Bootloader: Continue work on bootloader

Bootloader can now get the memory map and read cmdline from user.

Now 'just' video mode query, ext2 and ELF parsing are needed :D

bootloader/.gitignore

@@ -0,0 +1,3 @@
+test.img
+build/
+installer/build/

bootloader/arch/x86_64/boot.S

@@ -0,0 +1,667 @@
+# FIXME: don't assume 512 byte sectors
+.set SECTOR_SIZE_SHIFT,	9
+.set SECTOR_SIZE,		1 << SECTOR_SIZE_SHIFT
+
+.set SCREEN_WIDTH,	80
+.set SCREEN_HEIGHT,	25
+
+.code16
+
+#########################################
+#
+# STAGE 1 BOOTLOADER
+#
+# its sole purpose is to load stage2 from
+# bios boot partition
+#
+#########################################
+
+.section .stage1
+
+stage1_start:
+	jmp stage1_main
+
+# prints character to screen
+# al:		ascii character to print
+putc:
+	pusha
+	movb $0x0E, %ah
+	movb $0x00, %bh
+	int $0x10
+	popa
+	ret
+
+# prints null terminated string to screen
+# ds:si:	string address
+puts:
+	pushw %si
+	pushw %bx
+	pushw %ax
+
+	movb $0x0E, %ah
+	movb $0x00, %bh
+
+.puts_loop:
+	lodsb
+
+	test %al, %al
+	jz .puts_done
+
+	int $0x10
+	jmp .puts_loop
+
+.puts_done:
+	popw %ax
+	popw %bx
+	popw %si
+	ret
+
+# compares memory between addresses
+# si:		ptr1
+# di:		ptr2
+# cx:		bytes count
+# return:
+#	al: 1 if equal, 0 otherwise
+memcmp:
+	pushw %si
+	pushw %di
+
+	cld
+	repe cmpsb
+	setzb %al
+
+	popw %di
+	popw %si
+	ret
+
+
+# read sectors from disk
+# bx:eax:	lba start
+# cx:		lba count (has to less than 0x80)
+# dl:		drive number
+# ds:di:	physical address
+# returns only on success
+read_from_disk:
+	push %ax
+	push %si
+
+	# prepare disk read packet
+	mov $disk_address_packet, %si
+	movb $0x10,	0x00(%si)	# packet size
+	movb $0x00,	0x01(%si)	# always 0
+	movw %cx,	0x02(%si)	# lba count
+	movw %di,	0x04(%si)	# offset
+	movw %ds,	0x06(%si)	# segment
+	movl %eax,	0x08(%si)	# 32 bit lower lba
+	movw %bx,	0x0C(%si)	# 16 bit upper lba
+	movw $0,	0x0E(%si)	# zero
+
+	# issue read command
+	clc
+	mov $0x42, %ah
+	int $0x13
+	jc .read_failed
+
+	pop %si
+	pop %ax
+	ret
+
+
+# Validates that GPT header is valid and usable
+# doesn't return on invalid header
+validate_gpt_header:
+	# confirm header (starts with 'EFI PART')
+	cmpl $0x20494645, (gpt_header + 0)
+	jne .not_gpt_partition
+	cmpl $0x54524150, (gpt_header + 4)
+	jne .not_gpt_partition
+	ret
+
+
+# Find partition entry with type guid
+# si:	address of type guid
+# dl:	drive number
+# returns:
+#   al: non-zero if found
+#	di: address of partition entry
+find_gpt_partition_entry:
+	# eax := entry_count
+	movl (gpt_header + 80), %eax
+	test %eax, %eax
+	jz .no_gpt_partition_found
+
+	# edx:eax := eax * entry_size
+	pushw %dx
+	mull (gpt_header + 84)
+	test %edx, %edx
+	jnz .too_gpt_big_entries
+	popw %dx
+
+	# FIXME: read one entry array section at a time
+
+	# sector count := (arr_size + SECTOR_SIZE - 1) / SECTOR_SIZE
+	movl %eax, %ecx
+	shrl $SECTOR_SIZE_SHIFT, %ecx
+
+	# start lba
+	movl (gpt_header + 72), %eax
+	movw (gpt_header + 76), %bx
+
+	movw $gpt_entry_data, %di
+
+	call read_from_disk
+
+	# NOTE: 'only' 0xFFFF partitions supported,
+	#       although read will fail with more than 0x80
+	movw (gpt_header + 80), %cx
+
+.loop_gpt_entries:
+	pushw %cx
+	movw $16, %cx
+	call memcmp
+	popw %cx
+
+	testb %al, %al
+	jnz .gpt_partition_found
+
+	# add entry size to entry pointer
+	addw (gpt_header + 84), %di
+
+	loop .loop_gpt_entries
+
+.no_gpt_partition_found:
+	movb $0, %al
+	ret
+
+.gpt_partition_found:
+	movb $1, %al
+	ret
+
+
+stage1_main:
+	# setup segments
+	movw $0, %ax
+	movw %ax, %ds
+	movw %ax, %es
+
+	# setup stack
+	movw %ax, %ss
+	movw $0x7C00, %sp
+
+	# save boot disk number
+	movb %dl, (boot_disk_number)
+
+	# confirm that int 13h extensions are available
+	clc
+	movb $0x41, %ah
+	movw $0x55AA, %bx
+	movb (boot_disk_number), %dl
+	int $0x13
+	jc .no_int13h_ext
+
+	# read gpt header
+	movl $1, %eax
+	movw $0, %bx
+	movw $1, %cx
+	movb (boot_disk_number), %dl
+	movw $gpt_header, %di
+	call read_from_disk
+
+	call validate_gpt_header
+
+	movw $bios_boot_guid, %si
+	movb boot_disk_number, %dl
+	call find_gpt_partition_entry
+	testb %al, %al
+	jz .no_bios_boot_partition
+
+	# BIOS boot partiton found!
+
+	# first lba
+	movl 32(%di), %eax
+	movw $0, %bx
+
+	# count := last lba - first lba + 1
+	movl 40(%di), %ecx
+	subl %eax, %ecx
+	addl $1, %ecx
+
+	# calculate stage2 sector count
+	movw $((stage2_end - stage2_start + SECTOR_SIZE - 1) / SECTOR_SIZE), %cx
+
+	movb (boot_disk_number), %dl
+	movw $stage2_start, %di
+
+	call read_from_disk
+	jmp stage2_main
+
+print_and_halt:
+	call puts
+halt:
+	hlt
+	jmp halt
+
+.no_int13h_ext:
+	mov $no_int13_ext_msg, %si
+	jmp print_and_halt
+
+.read_failed:
+	mov $read_failed_msg, %si
+	jmp print_and_halt
+
+.not_gpt_partition:
+	mov $not_gpt_partition_msg, %si
+	jmp print_and_halt
+
+.no_bios_boot_partition:
+	mov $no_bios_boot_partition_msg, %si
+	jmp print_and_halt
+
+.too_gpt_big_entries:
+	mov $too_gpt_big_entries_msg, %si
+	jmp print_and_halt
+
+
+# 21686148-6449-6E6F-744E-656564454649
+bios_boot_guid:
+	.long 0x21686148		# little endian
+	.word 0x6449			# little endian
+	.word 0x6E6F			# little endian
+	.word 0x4E74			# big endian
+	.quad 0x494645646565	# big endian
+
+no_int13_ext_msg:
+	.asciz "no INT 13h ext"
+
+read_failed_msg:
+	.asciz "read error"
+
+not_gpt_partition_msg:
+	.asciz "not GPT"
+
+no_bios_boot_partition_msg:
+	.asciz "no bios boot partition"
+
+too_gpt_big_entries_msg:
+	.asciz "too big GPT array"
+
+boot_disk_number:
+	.skip 1
+
+
+#########################################
+#
+# STAGE 2 BOOTLOADER
+#
+#########################################
+
+.section .stage2
+
+stage2_start:
+
+# read a character from keyboard
+# return:
+#	al: ascii
+#	ah: bios scan code
+getc:
+	movb $0x00, %ah
+	int $0x16
+	ret
+
+
+# prints newline to screen
+print_newline:
+	pushw %ax
+	movb $'\r', %al
+	call putc
+	movb $'\n', %al
+	call putc
+	pop %ax
+	ret
+
+
+# prints backspace to screen, can go back a line
+print_backspace:
+	pusha
+
+	# get cursor position
+	movb $0x03, %ah
+	movb $0x00, %bh
+	int $0x10
+
+	# don't do anyting if on first row
+	testb %dh, %dh
+	jz .print_backspace_done
+
+	# go one line up if on first column
+	test %dl, %dl
+	jz .print_backspace_go_line_up
+
+	# otherwise decrease column
+	decb %dl
+	jmp .print_backspace_do_print
+
+.print_backspace_go_line_up:
+	# decrease row and set column to the last one
+	decb %dh
+	movb $(SCREEN_WIDTH - 1), %dl
+
+.print_backspace_do_print:
+	# set cursor position
+	movb $0x02, %ah
+	int $0x10
+
+	# print 'empty' character (space)
+	mov $' ', %al
+	call putc
+
+	# set cursor position
+	movb $0x02, %ah
+	int $0x10
+
+.print_backspace_done:
+	popa
+	ret
+
+
+# print number to screen
+# ax:	number to print
+# bx:	number base
+# cx:	min width (zero pads if shorter)
+printnum:
+	pusha
+	pushw %cx
+
+	movw $printnum_buffer, %si
+	xorw %cx, %cx
+
+.printnum_fill_loop:
+	# fill buffer with all remainders ax % bx
+	xorw %dx, %dx
+	divw %bx
+	movb %dl, (%si)
+	incw %si
+	incw %cx
+	testw %ax, %ax
+	jnz .printnum_fill_loop
+
+	# check if zero pad is required
+	popw %dx
+	cmpw %cx, %dx
+	jbe .printnum_print_loop
+
+	xchgw %dx, %cx
+	subw %dx, %cx
+	movb $'0', %al
+.printnum_pad_zeroes:
+	call putc
+	loop .printnum_pad_zeroes
+
+	movw %dx, %cx
+
+.printnum_print_loop:
+	decw %si
+	movb (%si), %al
+	cmpb $10, %al
+	jae 1f
+	addb $'0', %al
+	jmp 2f
+1:	addb $('a' - 10), %al
+2:	call putc
+	loop .printnum_print_loop
+
+	popa
+	ret
+
+
+# test if character is printable ascii
+# al:	character to test
+# sets ZF if is printable
+isprint:
+	cmpb $0x20, %al
+	jb .isprint_done
+	cmpb $0x7E, %al
+	ja .isprint_done
+	cmpb %al, %al
+.isprint_done:
+	ret
+
+
+# fills memory map data structure
+# doesn't return on error
+get_memory_map:
+	pusha
+
+	movl $0, (memory_map_entry_count)
+
+	movl $0x0000E820, %eax
+	movl $0x534D4150, %edx
+	xorl %ebx, %ebx
+	movl $20, %ecx
+	movw $memory_map_entries, %di
+
+	clc
+	int $0x15
+	# If first call returs with CF set, the call failed
+	jc .get_memory_map_error
+
+.get_memory_map_rest:
+	cmpl $0x534D4150, %eax
+	jne .get_memory_map_error
+
+	# FIXME: don't assume BIOS to always return 20 bytes
+	cmpl $20, %ecx
+	jne .get_memory_map_error
+
+	# increment entry count
+	incl (memory_map_entry_count)
+
+	# increment entry pointer
+	addw %cx, %di
+
+	# BIOS can indicate end of list by 0 in ebx
+	testl %ebx, %ebx
+	jz .get_memory_map_done
+
+	movl $0x0000E820, %eax
+	movl $0x534D4150, %edx
+
+	clc
+	int $0x15
+	# BIOS can indicate end of list by setting CF
+	jnc .get_memory_map_rest
+
+.get_memory_map_done:
+	popa
+	ret
+
+.get_memory_map_error:
+	movw $memory_map_error_msg, %si
+	jmp print_and_halt
+
+
+# fills command line buffer
+get_command_line:
+	pusha
+
+	movw $command_line_enter_msg, %si
+	call puts
+
+	movw $command_line_buffer, %di
+
+.get_command_line_loop:
+	call getc
+
+	cmpb $'\b', %al
+	je .get_command_line_backspace
+
+	# Not sure if some BIOSes return '\n' as enter, but check it just in case
+	cmpb $'\r', %al
+	je .get_command_line_done
+	cmpb $'\n', %al
+	je .get_command_line_done
+
+	call isprint
+	jnz .get_command_line_loop
+
+	# put byte to buffer
+	movb %al, (%di)
+	incw %di
+
+	# print byte
+	call putc
+
+	jmp .get_command_line_loop
+
+.get_command_line_backspace:
+	# don't do anything if at the beginning
+	cmpw $command_line_buffer, %di
+	je .get_command_line_loop
+
+	# decrement buffer pointer
+	decw %di
+
+	# erase byte in display
+	call print_backspace
+
+	jmp .get_command_line_loop
+
+.get_command_line_done:
+	# null terminate command line
+	movb $0, (%di)
+
+	call print_newline
+
+	popa
+	ret
+
+
+stage2_main:
+	# clear screen and enter 80x25 text mode
+	movb $0x03, %al
+	movb $0x00, %ah
+	int $0x10
+
+	# print hello message
+	movw $hello_msg, %si
+	call puts
+	call print_newline
+
+	call get_memory_map
+	call get_command_line
+
+	call print_newline
+
+	movw $start_kernel_load_msg, %si
+	call puts
+	call print_newline
+
+	movw $command_line_msg, %si
+	call puts
+	movw $command_line_buffer, %si
+	call puts
+	call print_newline
+
+	movw $memory_map_msg, %si
+	call puts
+	call print_newline
+
+	movl (memory_map_entry_count), %edx
+	movw $memory_map_entries, %si
+
+	movw $16, %bx
+	movw $4, %cx
+
+.loop_memory_map:
+	movb $' ', %al
+	call putc
+	call putc
+	call putc
+	call putc
+
+	movw 0x06(%si), %ax
+	call printnum
+	movw 0x04(%si), %ax
+	call printnum
+	movw 0x02(%si), %ax
+	call printnum
+	movw 0x00(%si), %ax
+	call printnum
+
+	movb $',', %al
+	call putc
+	movb $' ', %al
+	call putc
+
+	movw 0x0E(%si), %ax
+	call printnum
+	movw 0x0C(%si), %ax
+	call printnum
+	movw 0x0A(%si), %ax
+	call printnum
+	movw 0x08(%si), %ax
+	call printnum
+
+	movb $',', %al
+	call putc
+	movb $' ', %al
+	call putc
+
+	movw 0x12(%si), %ax
+	call printnum
+	movw 0x10(%si), %ax
+	call printnum
+
+	call print_newline
+
+	addw $20, %si
+
+	decl %edx
+	jnz .loop_memory_map
+
+
+	jmp halt
+
+
+hello_msg:
+	.asciz "This is banan-os bootloader"
+
+command_line_msg:
+command_line_enter_msg:
+	.asciz "cmdline: "
+
+memory_map_msg:
+	.asciz "memmap:"
+
+memory_map_error_msg:
+	.asciz "Failed to get memory map"
+
+start_kernel_load_msg:
+	.asciz "Starting to load kernel"
+
+stage2_end:
+
+
+.section .bss
+
+.align SECTOR_SIZE
+gpt_header:
+	.skip SECTOR_SIZE
+gpt_entry_data:
+	.skip SECTOR_SIZE
+
+disk_address_packet:
+	.skip 16
+
+printnum_buffer:
+	.skip 10
+
+memory_map_entry_count:
+	.skip 4
+# 100 entries should be enough...
+memory_map_entries:
+	.skip 20 * 100
+
+# 100 character command line
+command_line_buffer:
+	.skip 100

bootloader/arch/x86_64/linker.ld

@@ -0,0 +1,11 @@
+SECTIONS
+{
+	. = 0x7C00;
+	.stage1 : { *(.stage1) }
+
+	. = ALIGN(512);
+	.stage2 : { *(.stage2) }
+
+	. = ALIGN(512);
+	.bss : { *(.bss) }
+}

bootloader/build-and-run.sh

@@ -0,0 +1,45 @@
+#!/bin/sh
+
+set -e
+
+CURRENT_DIR=$(dirname $(realpath $0))
+
+INSTALLER_DIR=$CURRENT_DIR/installer
+INSTALLER_BUILD_DIR=$INSTALLER_DIR/build
+
+BUILD_DIR=$CURRENT_DIR/build
+DISK_IMAGE_PATH=$CURRENT_DIR/test.img
+
+if ! [ -d $INSTALLER_BUILD_DIR ]; then
+	mkdir -p $INSTALLER_BUILD_DIR
+	cd $INSTALLER_BUILD_DIR
+	cmake ..
+fi
+
+cd $INSTALLER_BUILD_DIR
+make
+
+cd $CURRENT_DIR
+
+echo creating clean disk image
+truncate --size 0 $DISK_IMAGE_PATH
+truncate --size 50M $DISK_IMAGE_PATH
+echo -ne 'g\nn\n\n\n+1M\nt 1\n4\nw\n' | fdisk $DISK_IMAGE_PATH > /dev/null
+
+mkdir -p $BUILD_DIR
+
+echo compiling bootloader
+x86_64-banan_os-as arch/x86_64/boot.S -o $BUILD_DIR/bootloader.o
+
+echo linking bootloader
+x86_64-banan_os-ld -nostdlib -T arch/x86_64/linker.ld $BUILD_DIR/bootloader.o -o $BUILD_DIR/bootloader
+
+echo installing bootloader
+$INSTALLER_BUILD_DIR/x86_64-banan_os-bootloader-installer $BUILD_DIR/bootloader $DISK_IMAGE_PATH
+
+if [ "$1" == "debug" ] ; then
+	QEMU_FLAGS="-s -S"
+fi
+
+echo running qemu
+env BANAN_DISK_IMAGE_PATH=${DISK_IMAGE_PATH} BANAN_ARCH=x86_64 ../script/qemu.sh $QEMU_FLAGS

bootloader/installer/CMakeLists.txt

@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 3.26)
+
+project(x86_64-banan_os-bootloader-installer CXX)
+
+set(SOURCES
+    crc32.cpp
+    ELF.cpp
+    GPT.cpp
+    GUID.cpp
+	main.cpp
+)
+
+add_executable(x86_64-banan_os-bootloader-installer ${SOURCES})
+target_compile_options(x86_64-banan_os-bootloader-installer PUBLIC -O2 -std=c++20)

bootloader/installer/ELF.cpp

@@ -0,0 +1,140 @@
+#include "ELF.h"
+
+#include <cassert>
+#include <cerrno>
+#include <cstring>
+#include <fcntl.h>
+#include <iostream>
+#include <sys/mman.h>
+#include <unistd.h>
+
+ELFFile::ELFFile(std::string_view path)
+	: m_path(path)
+{
+	m_fd = open(m_path.c_str(), O_RDONLY);
+	if (m_fd == -1)
+	{
+		std::cerr << "Could not open '" << m_path << "': " << std::strerror(errno) << std::endl;
+		return;
+	}
+
+	if (fstat(m_fd, &m_stat) == -1)
+	{
+		std::cerr << "Could not stat '" << m_path << "': " << std::strerror(errno) << std::endl;
+		return;
+	}
+
+	void* mmap_addr = mmap(nullptr, m_stat.st_size, PROT_READ, MAP_PRIVATE, m_fd, 0);
+	if (mmap_addr == MAP_FAILED)
+	{
+		std::cerr << "Could not mmap '" << m_path << "': " << std::strerror(errno) << std::endl;
+		return;
+	}
+	m_mmap = reinterpret_cast<uint8_t*>(mmap_addr);
+
+	if (!validate_elf_header())
+		return;
+
+	m_success = true;
+}
+
+ELFFile::~ELFFile()
+{
+	if (m_mmap)
+		munmap(m_mmap, m_stat.st_size);
+	m_mmap = nullptr;
+
+	if (m_fd != -1)
+		close(m_fd);
+	m_fd = -1;
+}
+
+const Elf64_Ehdr& ELFFile::elf_header() const
+{
+	return *reinterpret_cast<Elf64_Ehdr*>(m_mmap);
+}
+
+bool ELFFile::validate_elf_header() const
+{
+	if (m_stat.st_size < sizeof(Elf64_Ehdr))
+	{
+		std::cerr << m_path << " is too small to be a ELF executable" << std::endl;
+		return false;
+	}
+
+	const auto& elf_header = this->elf_header();
+
+	if (
+		elf_header.e_ident[EI_MAG0] != ELFMAG0 ||
+		elf_header.e_ident[EI_MAG1] != ELFMAG1 ||
+		elf_header.e_ident[EI_MAG2] != ELFMAG2 ||
+		elf_header.e_ident[EI_MAG3] != ELFMAG3
+	)
+	{
+		std::cerr << m_path << " doesn't have an ELF magic number" << std::endl;
+		return false;
+	}
+
+	if (elf_header.e_ident[EI_CLASS] != ELFCLASS64)
+	{
+		std::cerr << m_path << " is not 64 bit ELF" << std::endl;
+		return false;
+	}
+
+	if (elf_header.e_ident[EI_DATA] != ELFDATA2LSB)
+	{
+		std::cerr << m_path << " is not in little endian format" << std::endl;
+		return false;
+	}
+
+	if (elf_header.e_ident[EI_VERSION] != EV_CURRENT)
+	{
+		std::cerr << m_path << " has unsupported version" << std::endl;
+		return false;
+	}
+
+	if (elf_header.e_type != ET_EXEC)
+	{
+		std::cerr << m_path << " is not an executable ELF file" << std::endl;
+		return false;
+	}
+
+	if (elf_header.e_machine != EM_X86_64)
+	{
+		std::cerr << m_path << " is not an x86_64 ELF file" << std::endl;
+		return false;
+	}
+
+	return true;
+}
+
+const Elf64_Shdr& ELFFile::section_header(std::size_t index) const
+{
+	const auto& elf_header = this->elf_header();
+	assert(index < elf_header.e_shnum);
+	const uint8_t* section_array_start = m_mmap + elf_header.e_shoff;
+	return *reinterpret_cast<const Elf64_Shdr*>(section_array_start + index * elf_header.e_shentsize);
+}
+
+std::string_view ELFFile::section_name(const Elf64_Shdr& section_header) const
+{
+	const auto& elf_header = this->elf_header();
+	assert(elf_header.e_shstrndx != SHN_UNDEF);
+	const auto& section_string_table = this->section_header(elf_header.e_shstrndx);
+	const char* string_table_start = reinterpret_cast<const char*>(m_mmap + section_string_table.sh_offset);
+	return string_table_start + section_header.sh_name;
+}
+
+std::optional<std::span<const uint8_t>> ELFFile::find_section(std::string_view name) const
+{
+	const auto& elf_header = this->elf_header();
+	for (std::size_t i = 0; i < elf_header.e_shnum; i++)
+	{
+		const auto& section_header = this->section_header(i);
+		auto section_name = this->section_name(section_header);
+		if (section_name != name)
+			continue;
+		return std::span<const uint8_t>(m_mmap + section_header.sh_offset, section_header.sh_size);
+	}
+	return {};
+}

bootloader/installer/ELF.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <cstdint>
+#include <optional>
+#include <span>
+#include <string_view>
+#include <string>
+#include <sys/stat.h>
+
+#include <elf.h>
+
+class ELFFile
+{
+public:
+	ELFFile(std::string_view path);
+	~ELFFile();
+
+	const Elf64_Ehdr& elf_header() const;
+	std::optional<std::span<const uint8_t>> find_section(std::string_view name) const;
+
+	bool success() const { return m_success; }
+
+	std::string_view path() const { return m_path; }
+
+private:
+	const Elf64_Shdr& section_header(std::size_t index) const;
+	std::string_view section_name(const Elf64_Shdr&) const;
+	bool validate_elf_header() const;
+
+private:
+	const std::string	m_path;
+	bool				m_success	{ false };
+	int					m_fd		{ -1 };
+	struct stat			m_stat		{ };
+	uint8_t*			m_mmap		{ nullptr };
+};

bootloader/installer/GPT.cpp

@@ -0,0 +1,171 @@
+#include "crc32.h"
+#include "GPT.h"
+
+#include <cassert>
+#include <cerrno>
+#include <cstring>
+#include <fcntl.h>
+#include <iostream>
+#include <sys/mman.h>
+#include <unistd.h>
+
+// FIXME: don't assume 512 byte sectors
+#define SECTOR_SIZE 512
+
+GPTFile::GPTFile(std::string_view path)
+	: m_path(path)
+{
+	m_fd = open(m_path.c_str(), O_RDWR);
+	if (m_fd == -1)
+	{
+		std::cerr << "Could not open '" << m_path << "': " << std::strerror(errno) << std::endl;
+		return;
+	}
+
+	if (fstat(m_fd, &m_stat) == -1)
+	{
+		std::cerr << "Could not stat '" << m_path << "': " << std::strerror(errno) << std::endl;
+		return;
+	}
+
+	void* mmap_addr = mmap(nullptr, m_stat.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, m_fd, 0);
+	if (mmap_addr == MAP_FAILED)
+	{
+		std::cerr << "Could not mmap '" << m_path << "': " << std::strerror(errno) << std::endl;
+		return;
+	}
+	m_mmap = reinterpret_cast<uint8_t*>(mmap_addr);
+
+	if (!validate_gpt_header())
+		return;
+
+	m_success = true;
+}
+
+GPTFile::~GPTFile()
+{
+	if (m_mmap)
+		munmap(m_mmap, m_stat.st_size);
+	m_mmap = nullptr;
+
+	if (m_fd != -1)
+		close(m_fd);
+	m_fd = -1;
+}
+
+MBR& GPTFile::mbr()
+{
+	return *reinterpret_cast<MBR*>(m_mmap);
+}
+
+const GPTHeader& GPTFile::gpt_header() const
+{
+    return *reinterpret_cast<GPTHeader*>(m_mmap + SECTOR_SIZE);
+}
+
+bool GPTFile::install_bootcode(std::span<const uint8_t> boot_code)
+{
+	auto& mbr = this->mbr();
+
+	if (boot_code.size() > sizeof(mbr.boot_code))
+	{
+		std::cerr << m_path << ": can't fit " << boot_code.size() << " bytes of boot code in mbr (max is " << sizeof(mbr.boot_code) << ")" << std::endl;
+		return false;
+	}
+
+	// copy boot code
+	memcpy(mbr.boot_code, boot_code.data(), boot_code.size());
+
+	// setup mbr
+	mbr.unique_mbr_disk_signature = 0xdeadbeef;
+	mbr.unknown = 0;
+	mbr.signature = 0xAA55;
+
+	// setup mbr partition records
+	mbr.partition_records[0].boot_indicator = 0x00;
+	mbr.partition_records[0].starting_chs[0] = 0x00;
+	mbr.partition_records[0].starting_chs[1] = 0x02;
+	mbr.partition_records[0].starting_chs[2] = 0x00;
+	mbr.partition_records[0].os_type = 0xEE;
+	mbr.partition_records[0].ending_chs[0] = 0xFF;
+	mbr.partition_records[0].ending_chs[1] = 0xFF;
+	mbr.partition_records[0].ending_chs[2] = 0xFF;
+	mbr.partition_records[0].starting_lba = 1;
+	mbr.partition_records[0].size_in_lba = 0xFFFFFFFF;
+	memset(&mbr.partition_records[1], 0x00, sizeof(MBRPartitionRecord));
+	memset(&mbr.partition_records[2], 0x00, sizeof(MBRPartitionRecord));
+	memset(&mbr.partition_records[3], 0x00, sizeof(MBRPartitionRecord));
+
+	return true;
+}
+
+bool GPTFile::write_partition(std::span<const uint8_t> data, GUID type_guid)
+{
+	auto partition = find_partition(type_guid);
+	if (!partition.has_value())
+	{
+		std::cerr << m_path << ": could not find partition with type " << type_guid << std::endl;
+		return false;
+	}
+
+	const std::size_t partition_size = (partition->ending_lba - partition->starting_lba + 1) * SECTOR_SIZE;
+
+	if (data.size() > partition_size)
+	{
+		std::cerr << m_path << ": can't fit " << data.size() << " bytes of data to partition of size " << partition_size << std::endl;
+		return false;
+	}
+
+	memcpy(m_mmap + partition->starting_lba * SECTOR_SIZE, data.data(), data.size());
+
+	return true;
+}
+
+std::optional<GPTPartitionEntry> GPTFile::find_partition(const GUID& type_guid) const
+{
+	const auto& gpt_header = this->gpt_header();
+	const uint8_t* partition_entry_array_start = m_mmap + gpt_header.partition_entry_lba * SECTOR_SIZE;
+	for (std::size_t i = 0; i < gpt_header.number_of_partition_entries; i++)
+	{
+		const auto& partition_entry = *reinterpret_cast<const GPTPartitionEntry*>(partition_entry_array_start + i * gpt_header.size_of_partition_entry);
+		if (partition_entry.type_guid != type_guid)
+			continue;
+		return partition_entry;
+	}
+	return {};
+}
+
+bool GPTFile::validate_gpt_header() const
+{
+    if (SECTOR_SIZE + m_stat.st_size < sizeof(GPTHeader))
+    {
+		std::cerr << m_path << " is too small to have GPT header" << std::endl;
+        return false;
+    }
+
+    auto gpt_header = this->gpt_header();
+
+    if (std::memcmp(gpt_header.signature, "EFI PART", 8) != 0)
+    {
+		std::cerr << m_path << " doesn't contain GPT partition header signature" << std::endl;
+		return false;
+    }
+
+	const uint32_t header_crc32 = gpt_header.header_crc32;
+
+	gpt_header.header_crc32 = 0;
+	if (header_crc32 != crc32_checksum(reinterpret_cast<uint8_t*>(&gpt_header), gpt_header.header_size))
+	{
+		std::cerr << m_path << " has non-matching header crc32" << std::endl;
+		return false;
+	}
+
+	const std::size_t partition_array_size = gpt_header.number_of_partition_entries * gpt_header.size_of_partition_entry;
+	if (gpt_header.partition_entry_array_crc32 != crc32_checksum(m_mmap + gpt_header.partition_entry_lba * SECTOR_SIZE, partition_array_size))
+	{
+		std::cerr << m_path << " has non-matching partition entry crc32" << std::endl;
+		return false;
+	}
+
+    return true;
+}

bootloader/installer/GPT.h

@@ -0,0 +1,88 @@
+#pragma once
+
+#include "GUID.h"
+
+#include <cstdint>
+#include <optional>
+#include <span>
+#include <string_view>
+#include <string>
+#include <sys/stat.h>
+
+struct MBRPartitionRecord
+{
+	uint8_t boot_indicator;
+	uint8_t starting_chs[3];
+	uint8_t os_type;
+	uint8_t ending_chs[3];
+	uint32_t starting_lba;
+	uint32_t size_in_lba;
+} __attribute__((packed));
+
+struct MBR
+{
+	uint8_t boot_code[440];
+	uint32_t unique_mbr_disk_signature;
+	uint16_t unknown;
+	MBRPartitionRecord partition_records[4];
+	uint16_t signature;
+} __attribute__((packed));
+static_assert(sizeof(MBR) == 512);
+
+struct GPTPartitionEntry
+{
+	GUID type_guid;
+	GUID partition_guid;
+	uint64_t starting_lba;
+	uint64_t ending_lba;
+	uint64_t attributes;
+	uint16_t name[36];
+};
+static_assert(sizeof(GPTPartitionEntry) == 128);
+
+struct GPTHeader
+{
+	char signature[8];
+	uint32_t revision;
+	uint32_t header_size;
+	uint32_t header_crc32;
+	uint32_t reserved;
+	uint64_t my_lba;
+	uint64_t alternate_lba;
+	uint64_t first_usable_lba;
+	uint64_t last_usable_lba;
+	GUID disk_guid;
+	uint64_t partition_entry_lba;
+	uint32_t number_of_partition_entries;
+	uint32_t size_of_partition_entry;
+	uint32_t partition_entry_array_crc32;
+} __attribute__((packed));
+static_assert(sizeof(GPTHeader) == 92);
+
+class GPTFile
+{
+public:
+	GPTFile(std::string_view path);
+	~GPTFile();
+
+	bool install_bootcode(std::span<const uint8_t>);
+	bool write_partition(std::span<const uint8_t>, GUID type_guid);
+
+	const GPTHeader& gpt_header() const;
+
+	bool success() const { return m_success; }
+
+	std::string_view path() const { return m_path; }
+
+private:
+	MBR& mbr();
+	bool validate_gpt_header() const;
+	std::optional<GPTPartitionEntry> find_partition(const GUID& type_guid) const;
+
+private:
+	const std::string	m_path;
+	bool				m_success	{ false };
+	int					m_fd		{ -1 };
+	struct stat			m_stat		{ };
+	uint8_t*			m_mmap		{ nullptr };
+};

bootloader/installer/GUID.cpp

@@ -0,0 +1,26 @@
+#include "GUID.h"
+
+#include <iomanip>
+#include <cstring>
+
+bool GUID::operator==(const GUID& other) const
+{
+	return std::memcmp(this, &other, sizeof(GUID)) == 0;
+}
+
+std::ostream& operator<<(std::ostream& out, const GUID& guid)
+{
+	auto flags = out.flags();
+	out << std::hex << std::setfill('0');
+	out << std::setw(8) << guid.component1 << '-';
+	out << std::setw(4) << guid.component2 << '-';
+	out << std::setw(4) << guid.component3 << '-';
+
+	out << std::setw(2);
+	for (int i = 0; i < 2; i++) out << +guid.component45[i];
+	out << '-';
+	for (int i = 2; i < 6; i++) out << +guid.component45[i];
+
+	out.flags(flags);
+	return out;
+}

bootloader/installer/GUID.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <cstdint>
+#include <ostream>
+
+struct GUID
+{
+	uint32_t component1;
+	uint16_t component2;
+	uint16_t component3;
+	// last 2 components are combined so no packed needed
+	uint8_t component45[8];
+
+	bool operator==(const GUID& other) const;
+};
+
+std::ostream& operator<<(std::ostream& out, const GUID& guid);
+
+// unused		00000000-0000-0000-0000-000000000000
+static constexpr GUID unused_guid = {
+	0x00000000,
+	0x0000,
+	0x0000,
+	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
+};
+
+// bios boot	21686148-6449-6E6F-744E-656564454649
+static constexpr GUID bios_boot_guid = {
+	0x21686148,
+	0x6449,
+	0x6E6F,
+	{ 0x74, 0x4E, 0x65, 0x65, 0x64, 0x45, 0x46, 0x49 }
+};

bootloader/installer/build.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+g++ -O2 -std=c++20 main.cpp crc32.cpp ELF.cpp GPT.cpp GUID.cpp -o install-bootloader

bootloader/installer/crc32.cpp

@@ -0,0 +1,80 @@
+#include "crc32.h"
+
+static constexpr uint32_t crc32_table[256] =
+{
+	0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA,
+	0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
+	0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
+	0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
+	0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE,
+	0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
+	0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC,
+	0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
+	0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
+	0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
+	0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940,
+	0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
+	0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116,
+	0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
+	0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
+	0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
+	0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A,
+	0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
+	0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818,
+	0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
+	0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
+	0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
+	0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C,
+	0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
+	0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2,
+	0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
+	0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
+	0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
+	0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086,
+	0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
+	0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4,
+	0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
+	0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
+	0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
+	0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8,
+	0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
+	0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE,
+	0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
+	0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
+	0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
+	0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252,
+	0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
+	0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60,
+	0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
+	0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
+	0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
+	0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04,
+	0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
+	0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A,
+	0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
+	0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
+	0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
+	0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E,
+	0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
+	0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C,
+	0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
+	0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
+	0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
+	0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0,
+	0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
+	0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6,
+	0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
+	0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
+	0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D,
+};
+
+uint32_t crc32_checksum(const uint8_t* data, std::size_t count)
+{
+	uint32_t crc32 = 0xFFFFFFFF;
+	for (size_t i = 0; i < count; i++)
+	{
+		uint8_t index = (crc32 ^ data[i]) & 0xFF;
+		crc32 = (crc32 >> 8) ^ crc32_table[index];
+	}
+	return crc32 ^ 0xFFFFFFFF;
+}

bootloader/installer/crc32.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+
+uint32_t crc32_checksum(const uint8_t* data, std::size_t count);

bootloader/installer/main.cpp

@@ -0,0 +1,41 @@
+#include "ELF.h"
+#include "GPT.h"
+
+#include <iostream>
+
+int main(int argc, char** argv)
+{
+	using namespace std::string_view_literals;
+
+	if (argc != 3)
+	{
+		std::fprintf(stderr, "usage: %s BOOTLOADER DISK_IMAGE}\n", argv[0]);
+		return 1;
+	}
+
+	ELFFile bootloader(argv[1]);
+	if (!bootloader.success())
+		return 1;
+
+	auto stage1 = bootloader.find_section(".stage1"sv);
+	auto stage2 = bootloader.find_section(".stage2"sv);
+	if (!stage1.has_value() || !stage2.has_value())
+	{
+		std::cerr << bootloader.path() << " doesn't contain .stage1 and .stage2 sections" << std::endl;
+		return 1;
+	}
+
+	GPTFile disk_image(argv[2]);
+	if (!disk_image.success())
+		return 1;
+
+	if (!disk_image.install_bootcode(*stage1))
+		return 1;
+	std::cout << "wrote stage1 bootloader" << std::endl;
+
+	if (!disk_image.write_partition(*stage2, bios_boot_guid))
+		return 1;
+	std::cout << "wrote stage2 bootloader" << std::endl;
+
+	return 0;
+}

kernel/CMakeLists.txt

@@ -26,8 +26,6 @@ set(KERNEL_SOURCES
 	kernel/FS/Pipe.cpp
 	kernel/FS/ProcFS/FileSystem.cpp
 	kernel/FS/ProcFS/Inode.cpp
-	kernel/FS/RamFS/FileSystem.cpp
-	kernel/FS/RamFS/Inode.cpp
 	kernel/FS/TmpFS/FileSystem.cpp
 	kernel/FS/TmpFS/Inode.cpp
 	kernel/FS/VirtualFileSystem.cpp

kernel/include/kernel/Device/Device.h

@@ -1,11 +1,11 @@
 #pragma once
 
-#include <kernel/FS/RamFS/Inode.h>
+#include <kernel/FS/TmpFS/Inode.h>
 
 namespace Kernel
 {
 
-	class Device : public RamInode
+	class Device : public TmpInode
 	{
 	public:
 		virtual ~Device() = default;

kernel/include/kernel/FS/DevFS/FileSystem.h

@@ -1,13 +1,13 @@
 #pragma once
 
 #include <kernel/Device/Device.h>
-#include <kernel/FS/RamFS/FileSystem.h>
+#include <kernel/FS/TmpFS/FileSystem.h>
 #include <kernel/Semaphore.h>
 
 namespace Kernel
 {
 
-	class DevFileSystem final : public RamFileSystem
+	class DevFileSystem final : public TmpFileSystem
 	{
 	public:
 		static void initialize();
@@ -16,7 +16,7 @@ namespace Kernel
 		void initialize_device_updater();
 
 		void add_device(BAN::RefPtr<Device>);
-		void add_inode(BAN::StringView path, BAN::RefPtr<RamInode>);
+		void add_inode(BAN::StringView path, BAN::RefPtr<TmpInode>);
 		void for_each_device(const BAN::Function<BAN::Iteration(Device*)>& callback);
 
 		dev_t get_next_dev() const;
@@ -25,8 +25,8 @@ namespace Kernel
 		void initiate_sync(bool should_block);
 
 	private:
-		DevFileSystem(size_t size)
+		DevFileSystem()
-			: RamFileSystem(size)
+			: TmpFileSystem(-1)
 		{ }
 
 	private:

kernel/include/kernel/FS/RamFS/FileSystem.h

@@ -1,47 +0,0 @@
-#pragma once
-
-#include <BAN/HashMap.h>
-#include <BAN/Iteration.h>
-#include <kernel/FS/FileSystem.h>
-#include <kernel/SpinLock.h>
-
-namespace Kernel
-{
-
-	class RamInode;
-	class RamDirectoryInode;
-
-	class RamFileSystem : public FileSystem
-	{
-	public:
-		static BAN::ErrorOr<RamFileSystem*> create(size_t size, mode_t, uid_t, gid_t);
-		virtual ~RamFileSystem() = default;
-
-		BAN::ErrorOr<void> set_root_inode(BAN::RefPtr<RamDirectoryInode>);
-		virtual BAN::RefPtr<Inode> root_inode() override { return m_inodes[m_root_inode]; }
-
-		BAN::ErrorOr<void> add_inode(BAN::RefPtr<RamInode>);
-		BAN::ErrorOr<BAN::RefPtr<RamInode>> get_inode(ino_t);
-
-		blksize_t blksize() const { return m_blksize; }
-		ino_t next_ino() { return m_next_ino++; }
-
-		void for_each_inode(const BAN::Function<BAN::Iteration(BAN::RefPtr<RamInode>)>& callback);
-
-	protected:
-		RamFileSystem(size_t size)
-			: m_size(size)
-		{ }
-
-	private:
-		RecursiveSpinLock m_lock;
-		size_t m_size { 0 };
-
-		BAN::HashMap<ino_t, BAN::RefPtr<RamInode>> m_inodes;
-		ino_t m_root_inode { 0 };
-
-		const blksize_t m_blksize = PAGE_SIZE;
-		ino_t m_next_ino { 1 };
-	};
-
-}

kernel/include/kernel/FS/RamFS/Inode.h

@@ -1,141 +0,0 @@
-#pragma once
-
-#include <kernel/FS/Inode.h>
-
-#include <limits.h>
-
-namespace Kernel
-{
-
-	class RamFileSystem;
-
-	class RamInode : public Inode
-	{
-	public:
-		virtual ~RamInode() = default;
-
-		virtual ino_t		ino()		const override { return m_inode_info.ino; }
-		virtual Mode		mode()		const override { return { m_inode_info.mode }; }
-		virtual nlink_t		nlink()		const override { return m_inode_info.nlink; }
-		virtual uid_t		uid()		const override { return m_inode_info.uid; }
-		virtual gid_t		gid()		const override { return m_inode_info.gid; }
-		virtual off_t		size()		const override { return m_inode_info.size; }
-		virtual timespec	atime()		const override { return m_inode_info.atime; }
-		virtual timespec	mtime()		const override { return m_inode_info.mtime; }
-		virtual timespec	ctime()		const override { return m_inode_info.ctime; }
-		virtual blksize_t	blksize()	const override { return m_inode_info.blksize; }
-		virtual blkcnt_t	blocks()	const override { return m_inode_info.blocks; }
-		virtual dev_t		dev()		const override { return m_inode_info.dev; }
-		virtual dev_t		rdev()		const override { return m_inode_info.rdev; }
-
-		void add_link() { m_inode_info.nlink++; }
-
-	protected:
-		struct FullInodeInfo
-		{
-			FullInodeInfo(RamFileSystem&, mode_t, uid_t, gid_t);
-			ino_t		ino;
-			mode_t		mode;
-			nlink_t		nlink;
-			uid_t		uid;
-			gid_t		gid;
-			off_t		size;
-			timespec	atime;
-			timespec	mtime;
-			timespec	ctime;
-			blksize_t	blksize;
-			blkcnt_t	blocks;
-			dev_t		dev;
-			dev_t		rdev;
-		};
-
-		RamInode(RamFileSystem& fs, const FullInodeInfo& inode_info)
-			: m_fs(fs)
-			, m_inode_info(inode_info)
-		{
-			ASSERT((inode_info.mode & Inode::Mode::TYPE_MASK) == 0);
-		}
-
-		virtual BAN::ErrorOr<void> chmod_impl(mode_t) override;
-
-	protected:
-		RamFileSystem& m_fs;
-		FullInodeInfo m_inode_info;
-	};
-
-	class RamFileInode : public RamInode
-	{
-	public:
-		static BAN::ErrorOr<BAN::RefPtr<RamFileInode>> create(RamFileSystem&, mode_t, uid_t, gid_t);
-		~RamFileInode() = default;
-
-	protected:
-		RamFileInode(RamFileSystem&, const FullInodeInfo&);
-
-		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
-		virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan) override;
-		virtual BAN::ErrorOr<void> truncate_impl(size_t) override;
-
-	private:
-		BAN::Vector<uint8_t> m_data;
-
-		friend class RamFileSystem;
-	};
-
-	class RamDirectoryInode : public RamInode
-	{
-	public:
-		static BAN::ErrorOr<BAN::RefPtr<RamDirectoryInode>> create(RamFileSystem&, ino_t parent, mode_t, uid_t, gid_t);
-		~RamDirectoryInode() = default;
-
-		BAN::ErrorOr<void> add_inode(BAN::StringView, BAN::RefPtr<RamInode>);
-
-	protected:
-		RamDirectoryInode(RamFileSystem&, const FullInodeInfo&, ino_t parent);
-
-		virtual BAN::ErrorOr<BAN::RefPtr<Inode>> find_inode_impl(BAN::StringView) override;
-		virtual BAN::ErrorOr<void> list_next_inodes_impl(off_t, DirectoryEntryList*, size_t) override;
-		virtual BAN::ErrorOr<void> create_file_impl(BAN::StringView, mode_t, uid_t, gid_t) override;
-		virtual BAN::ErrorOr<void> create_directory_impl(BAN::StringView, mode_t, uid_t, gid_t) override;
-		virtual BAN::ErrorOr<void> unlink_impl(BAN::StringView) override;
-
-	private:
-		static constexpr size_t m_name_max = NAME_MAX;
-		struct Entry
-		{
-			char name[m_name_max + 1];
-			size_t name_len = 0;
-			ino_t ino;
-			uint8_t type;
-		};
-
-	private:
-		BAN::Vector<Entry> m_entries;
-		const ino_t m_parent;
-
-		friend class RamFileSystem;
-	};
-
-	class RamSymlinkInode final : public RamInode
-	{
-	public:
-		static BAN::ErrorOr<BAN::RefPtr<RamSymlinkInode>> create(RamFileSystem&, BAN::StringView target, mode_t, uid_t, gid_t);
-		~RamSymlinkInode() = default;
-
-		virtual off_t size() const override { return m_target.size(); }
-
-		BAN::ErrorOr<void> set_link_target(BAN::StringView);
-
-	protected:
-		virtual BAN::ErrorOr<BAN::String> link_target_impl() override;
-
-	private:
-		RamSymlinkInode(RamFileSystem&, const FullInodeInfo&, BAN::String&&);
-
-	private:
-		BAN::String m_target;
-
-		friend class RamFileSystem;
-	};
-
-}

kernel/include/kernel/FS/TmpFS/FileSystem.h

@@ -4,6 +4,7 @@
 #include <BAN/Iteration.h>
 #include <kernel/FS/FileSystem.h>
 #include <kernel/FS/TmpFS/Inode.h>
+#include <kernel/LockGuard.h>
 #include <kernel/Memory/PageTable.h>
 #include <kernel/SpinLock.h>
 
@@ -25,6 +26,12 @@ namespace Kernel
 			requires BAN::is_same_v<decltype(func(buffer)), void>;
 		};
 
+		template<typename F>
+		concept for_each_inode_callback = requires(F func, BAN::RefPtr<TmpInode> inode)
+		{
+			requires BAN::is_same_v<decltype(func(inode)), BAN::Iteration>;
+		};
+
 	}
 
 
@@ -57,6 +64,9 @@ namespace Kernel
 		void free_block(size_t index);
 		BAN::ErrorOr<size_t> allocate_block();
 
+		template<TmpFuncs::for_each_inode_callback F>
+		void for_each_inode(F callback);
+
 	private:
 		struct PageInfo
 		{
@@ -135,11 +145,13 @@ namespace Kernel
 			(PAGE_SIZE / sizeof(TmpInodeInfo));
 
 		const size_t m_max_pages;
+		size_t m_used_pages { 0 };
 	};
 
 	template<TmpFuncs::with_block_buffer_callback F>
 	void TmpFileSystem::with_block_buffer(size_t index, F callback)
 	{
+		LockGuard _(m_lock);
 		paddr_t block_paddr = find_block(index);
 		PageTable::with_fast_page(block_paddr, [&] {
 			BAN::ByteSpan buffer(reinterpret_cast<uint8_t*>(PageTable::fast_page()), PAGE_SIZE);
@@ -147,4 +159,22 @@ namespace Kernel
 		});
 	}
 
+	template<TmpFuncs::for_each_inode_callback F>
+	void TmpFileSystem::for_each_inode(F callback)
+	{
+		LockGuard _(m_lock);
+		for (auto& [_, inode] : m_inode_cache)
+		{
+			switch (callback(inode))
+			{
+				case BAN::Iteration::Continue:
+					break;
+				case BAN::Iteration::Break:
+					return;
+				default:
+					ASSERT_NOT_REACHED();
+			}
+		}
+	}
+
 }

kernel/include/kernel/FS/TmpFS/Inode.h

@@ -35,8 +35,8 @@ namespace Kernel
 		virtual timespec	ctime()		const override final { return m_inode_info.ctime; }
 		virtual blksize_t	blksize()	const override final { return PAGE_SIZE; }
 		virtual blkcnt_t	blocks()	const override final { return m_inode_info.blocks; }
-		virtual dev_t		dev()		const override final { return 0; } // TODO
+		virtual dev_t		dev()		const override		 { return 0; } // TODO
-		virtual dev_t		rdev()		const override final { return 0; } // TODO
+		virtual dev_t		rdev()		const override		 { return 0; } // TODO
 
 	public:
 		static BAN::ErrorOr<BAN::RefPtr<TmpInode>> create_from_existing(TmpFileSystem&, ino_t, const TmpInodeInfo&);
@@ -83,10 +83,16 @@ namespace Kernel
 	class TmpSymlinkInode : public TmpInode
 	{
 	public:
+		static BAN::ErrorOr<BAN::RefPtr<TmpSymlinkInode>> create_new(TmpFileSystem&, mode_t, uid_t, gid_t, BAN::StringView target);
 		~TmpSymlinkInode();
 
+		BAN::ErrorOr<void> set_link_target(BAN::StringView);
+
+	protected:
+		virtual BAN::ErrorOr<BAN::String> link_target_impl() override;
+
 	private:
-		TmpSymlinkInode(TmpFileSystem&, ino_t, const TmpInodeInfo&, BAN::StringView target);
+		TmpSymlinkInode(TmpFileSystem&, ino_t, const TmpInodeInfo&);
 	};
 
 	class TmpDirectoryInode : public TmpInode

kernel/include/kernel/Input/PS2Controller.h

@@ -12,6 +12,8 @@ namespace Kernel::Input
 		PS2Device();
 		virtual ~PS2Device() {}
 
+		virtual void send_initialize() = 0;
+
 		virtual BAN::StringView name() const override { return m_name; }
 
 	private:

kernel/include/kernel/Input/PS2Keyboard.h

@@ -28,13 +28,13 @@ namespace Kernel::Input
 
 	public:
 		static BAN::ErrorOr<PS2Keyboard*> create(PS2Controller&);
+		virtual void send_initialize() override;
 
 		virtual void handle_irq() override;
 		virtual void update() override;
 
 	private:
 		PS2Keyboard(PS2Controller& controller);
-		BAN::ErrorOr<void> initialize();
 
 		void append_command_queue(uint8_t);
 		void append_command_queue(uint8_t, uint8_t);

kernel/include/kernel/Storage/StorageDevice.h

@@ -51,9 +51,6 @@ namespace Kernel
 	public:
 		virtual bool is_partition() const override { return true; }
 
-		virtual Mode mode() const override { return { Mode::IFBLK | Mode::IRUSR | Mode::IRGRP }; }
-		virtual uid_t uid() const override { return 0; }
-		virtual gid_t gid() const override { return 0; }
 		virtual dev_t rdev() const override { return m_rdev; }
 
 	protected:

kernel/kernel/Device/Device.cpp

@@ -5,7 +5,12 @@ namespace Kernel
 {
 
 	Device::Device(mode_t mode, uid_t uid, gid_t gid)
-		: RamInode(DevFileSystem::get(), FullInodeInfo(DevFileSystem::get(), mode, uid, gid))
+		// FIXME: what the fuck is this
+		: TmpInode(
+			DevFileSystem::get(),
+			MUST(DevFileSystem::get().allocate_inode(create_inode_info(mode, uid, gid))),
+			create_inode_info(mode, uid, gid)
+		)
 	{ }
 
 }

kernel/kernel/FS/DevFS/FileSystem.cpp

@@ -2,7 +2,7 @@
 #include <kernel/Device/NullDevice.h>
 #include <kernel/Device/ZeroDevice.h>
 #include <kernel/FS/DevFS/FileSystem.h>
-#include <kernel/FS/RamFS/Inode.h>
+#include <kernel/FS/TmpFS/Inode.h>
 #include <kernel/LockGuard.h>
 #include <kernel/Process.h>
 #include <kernel/Storage/StorageDevice.h>
@@ -16,12 +16,10 @@ namespace Kernel
 	void DevFileSystem::initialize()
 	{
 		ASSERT(s_instance == nullptr);
-		s_instance = new DevFileSystem(1024 * 1024);
+		s_instance = new DevFileSystem();
 		ASSERT(s_instance);
 
-		auto root_inode = MUST(RamDirectoryInode::create(*s_instance, 0, 0755, 0, 0));
+		MUST(s_instance->TmpFileSystem::initialize(0755, 0, 0));
-		MUST(s_instance->set_root_inode(root_inode));
-
 		s_instance->add_device(MUST(NullDevice::create(0666, 0, 0)));
 		s_instance->add_device(MUST(ZeroDevice::create(0666, 0, 0)));
 	}
@@ -41,10 +39,10 @@ namespace Kernel
 				{
 					s_instance->m_device_lock.lock();
 					s_instance->for_each_inode(
-						[](BAN::RefPtr<RamInode> inode)
+						[](BAN::RefPtr<TmpInode> inode)
 						{
 							if (inode->is_device())
-								((Device*)inode.ptr())->update();
+								reinterpret_cast<Device*>(inode.ptr())->update();
 							return BAN::Iteration::Continue;
 						}
 					);
@@ -74,11 +72,11 @@ namespace Kernel
 					}
 
 					s_instance->for_each_inode(
-						[](BAN::RefPtr<RamInode> inode)
+						[](BAN::RefPtr<TmpInode> inode)
 						{
 							if (inode->is_device())
 								if (((Device*)inode.ptr())->is_storage_device())
-									if (auto ret = ((StorageDevice*)inode.ptr())->sync_disk_cache(); ret.is_error())
+									if (auto ret = reinterpret_cast<StorageDevice*>(inode.ptr())->sync_disk_cache(); ret.is_error())
 										dwarnln("disk sync: {}", ret.error());
 							return BAN::Iteration::Continue;
 						}
@@ -120,24 +118,24 @@ namespace Kernel
 	void DevFileSystem::add_device(BAN::RefPtr<Device> device)
 	{
 		ASSERT(!device->name().contains('/'));
-		MUST(reinterpret_cast<RamDirectoryInode*>(root_inode().ptr())->add_inode(device->name(), device));
+		MUST(reinterpret_cast<TmpDirectoryInode*>(root_inode().ptr())->link_inode(*device, device->name()));
 	}
 
-	void DevFileSystem::add_inode(BAN::StringView path, BAN::RefPtr<RamInode> inode)
+	void DevFileSystem::add_inode(BAN::StringView path, BAN::RefPtr<TmpInode> inode)
 	{
 		ASSERT(!path.contains('/'));
-		MUST(reinterpret_cast<RamDirectoryInode*>(root_inode().ptr())->add_inode(path, inode));
+		MUST(reinterpret_cast<TmpDirectoryInode*>(root_inode().ptr())->link_inode(*inode, path));
 	}
 
 	void DevFileSystem::for_each_device(const BAN::Function<BAN::Iteration(Device*)>& callback)
 	{
 		LockGuard _(m_device_lock);
 		for_each_inode(
-			[&](BAN::RefPtr<Kernel::RamInode> inode)
+			[&](BAN::RefPtr<Kernel::TmpInode> inode)
 			{
 				if (!inode->is_device())
 					return BAN::Iteration::Continue;
-				return callback((Device*)inode.ptr());
+				return callback(reinterpret_cast<Device*>(inode.ptr()));
 			}
 		);
 	}

kernel/kernel/FS/RamFS/FileSystem.cpp

@@ -1,65 +0,0 @@
-#include <BAN/ScopeGuard.h>
-#include <kernel/FS/RamFS/FileSystem.h>
-#include <kernel/FS/RamFS/Inode.h>
-#include <kernel/LockGuard.h>
-
-namespace Kernel
-{
-
-	BAN::ErrorOr<RamFileSystem*> RamFileSystem::create(size_t size, mode_t mode, uid_t uid, gid_t gid)
-	{
-		auto* ramfs = new RamFileSystem(size);
-		if (ramfs == nullptr)
-			return BAN::Error::from_errno(ENOMEM);
-
-		BAN::ScopeGuard deleter([ramfs] { delete ramfs; });
-
-		auto root_inode = TRY(RamDirectoryInode::create(*ramfs, 0, mode, uid, gid));
-		TRY(ramfs->set_root_inode(root_inode));;
-
-		deleter.disable();
-
-		return ramfs;
-	}
-
-	BAN::ErrorOr<void> RamFileSystem::set_root_inode(BAN::RefPtr<RamDirectoryInode> root_inode)
-	{
-		LockGuard _(m_lock);
-		ASSERT(m_root_inode == 0);
-		TRY(add_inode(root_inode));
-		m_root_inode = root_inode->ino();
-		return {};
-	}
-
-	BAN::ErrorOr<void> RamFileSystem::add_inode(BAN::RefPtr<RamInode> inode)
-	{
-		LockGuard _(m_lock);
-		if (m_inodes.contains(inode->ino()))
-			return BAN::Error::from_errno(EEXIST);
-		TRY(m_inodes.insert(inode->ino(), inode));
-		return {};
-	}
-
-	BAN::ErrorOr<BAN::RefPtr<RamInode>> RamFileSystem::get_inode(ino_t ino)
-	{
-		LockGuard _(m_lock);
-		if (!m_inodes.contains(ino))
-			return BAN::Error::from_errno(ENOENT);
-		return m_inodes[ino];
-	}
-
-	void RamFileSystem::for_each_inode(const BAN::Function<BAN::Iteration(BAN::RefPtr<RamInode>)>& callback)
-	{
-		LockGuard _(m_lock);
-		for (auto& [_, inode] : m_inodes)
-		{
-			auto decision = callback(inode);
-			if (decision == BAN::Iteration::Break)
-				break;
-			if (decision == BAN::Iteration::Continue)
-				continue;
-			ASSERT_NOT_REACHED();
-		}
-	}
-
-}

kernel/kernel/FS/RamFS/Inode.cpp

@@ -1,321 +0,0 @@
-#include <kernel/FS/RamFS/FileSystem.h>
-#include <kernel/FS/RamFS/Inode.h>
-#include <kernel/Timer/Timer.h>
-
-namespace Kernel
-{
-
-	RamInode::FullInodeInfo::FullInodeInfo(RamFileSystem& fs, mode_t mode, uid_t uid, gid_t gid)
-	{
-		timespec current_time = SystemTimer::get().real_time();
-
-		this->ino = fs.next_ino();
-		this->mode = mode;
-		this->nlink = 1;
-		this->uid = uid;
-		this->gid = gid;
-		this->size = 0;
-		this->atime = current_time;
-		this->mtime = current_time;
-		this->ctime = current_time;
-		this->blksize = fs.blksize();
-		this->blocks = 0;
-
-		// TODO
-		this->dev = 0;
-		this->rdev = 0;
-	}
-
-
-	BAN::ErrorOr<void> RamInode::chmod_impl(mode_t mode)
-	{
-		ASSERT((mode & Inode::Mode::TYPE_MASK) == 0);
-		m_inode_info.mode = (m_inode_info.mode & Inode::Mode::TYPE_MASK) | mode;
-		return {};
-	}
-
-	/*
-
-		RAM FILE INODE
-
-	*/
-
-	BAN::ErrorOr<BAN::RefPtr<RamFileInode>> RamFileInode::create(RamFileSystem& fs, mode_t mode, uid_t uid, gid_t gid)
-	{
-		FullInodeInfo inode_info(fs, mode, uid, gid);
-
-		auto* ram_inode = new RamFileInode(fs, inode_info);
-		if (ram_inode == nullptr)
-			return BAN::Error::from_errno(ENOMEM);
-		return BAN::RefPtr<RamFileInode>::adopt(ram_inode);
-	}
-
-	RamFileInode::RamFileInode(RamFileSystem& fs, const FullInodeInfo& inode_info)
-		: RamInode(fs, inode_info)
-	{
-		m_inode_info.mode |= Inode::Mode::IFREG;
-	}
-
-	BAN::ErrorOr<size_t> RamFileInode::read_impl(off_t offset, BAN::ByteSpan buffer)
-	{
-		ASSERT(offset >= 0);
-		if (offset >= size())
-			return 0;
-		size_t to_copy = BAN::Math::min<size_t>(m_inode_info.size - offset, buffer.size());
-		memcpy(buffer.data(), m_data.data() + offset, to_copy);
-		return to_copy;
-	}
-
-	BAN::ErrorOr<size_t> RamFileInode::write_impl(off_t offset, BAN::ConstByteSpan buffer)
-	{
-		ASSERT(offset >= 0);
-		if (offset + buffer.size() > (size_t)size())
-			TRY(truncate_impl(offset + buffer.size()));
-		memcpy(m_data.data() + offset, buffer.data(), buffer.size());
-		return buffer.size();
-	}
-
-	BAN::ErrorOr<void> RamFileInode::truncate_impl(size_t new_size)
-	{
-		TRY(m_data.resize(new_size, 0));
-		m_inode_info.size   = m_data.size();
-		m_inode_info.blocks = BAN::Math::div_round_up<size_t>(size(), blksize());
-		return {};
-	}
-
-	/*
-
-		RAM DIRECTORY INODE
-
-	*/
-
-	BAN::ErrorOr<BAN::RefPtr<RamDirectoryInode>> RamDirectoryInode::create(RamFileSystem& fs, ino_t parent, mode_t mode, uid_t uid, gid_t gid)
-	{
-		FullInodeInfo inode_info(fs, mode, uid, gid);
-
-		// "." links to this
-		inode_info.nlink++;
-
-		// ".." links to this or parent
-		if (parent)
-			TRY(fs.get_inode(parent))->add_link();
-		else
-		{
-			inode_info.nlink++;
-			parent = inode_info.ino;
-		}
-
-		auto* ram_inode = new RamDirectoryInode(fs, inode_info, parent);
-		if (ram_inode == nullptr)
-			return BAN::Error::from_errno(ENOMEM);
-		return BAN::RefPtr<RamDirectoryInode>::adopt(ram_inode);
-	}
-
-	RamDirectoryInode::RamDirectoryInode(RamFileSystem& fs, const FullInodeInfo& inode_info, ino_t parent)
-		: RamInode(fs, inode_info)
-		, m_parent(parent)
-	{
-		m_inode_info.mode |= Inode::Mode::IFDIR;
-	}
-
-	BAN::ErrorOr<BAN::RefPtr<Inode>> RamDirectoryInode::find_inode_impl(BAN::StringView name)
-	{
-		if (name == "."sv)
-		{
-			BAN::RefPtr<Inode> inode = TRY(m_fs.get_inode(ino()));
-			return inode;
-		}
-
-		if (name == ".."sv)
-		{
-			BAN::RefPtr<Inode> inode = TRY(m_fs.get_inode(m_parent));
-			return inode;
-		}
-
-		for (const auto& entry : m_entries)
-		{
-			if (name == entry.name)
-			{
-				BAN::RefPtr<Inode> inode = TRY(m_fs.get_inode(entry.ino));
-				return inode;
-			}
-		}
-
-		return BAN::Error::from_errno(ENOENT);
-	}
-
-	BAN::ErrorOr<void> RamDirectoryInode::list_next_inodes_impl(off_t offset, DirectoryEntryList* list, size_t list_size)
-	{
-		ASSERT(offset >= 0);
-
-		// TODO: don't require memory for all entries on single call
-		if (offset != 0)
-		{
-			list->entry_count = 0;
-			return {};
-		}
-
-		size_t needed_size = sizeof(DirectoryEntryList);
-		needed_size += sizeof(DirectoryEntry) + 2; // "."
-		needed_size += sizeof(DirectoryEntry) + 3; // ".."
-		for (auto& entry : m_entries)
-			needed_size += sizeof(DirectoryEntry) + entry.name_len + 1;
-		if (needed_size > list_size)
-			return BAN::Error::from_errno(EINVAL);
-
-		DirectoryEntry* ptr = list->array;
-
-		// "."
-		{
-			ptr->dirent.d_ino = ino();
-			ptr->dirent.d_type = DT_DIR;
-			ptr->rec_len = sizeof(DirectoryEntry) + 2;
-			strcpy(ptr->dirent.d_name, ".");
-			ptr = ptr->next();
-		}
-
-		// ".."
-		{
-			ptr->dirent.d_ino = m_parent;
-			ptr->dirent.d_type = DT_DIR;
-			ptr->rec_len = sizeof(DirectoryEntry) + 3;
-			strcpy(ptr->dirent.d_name, "..");
-			ptr = ptr->next();
-		}
-
-		for (auto& entry : m_entries)
-		{
-			ptr->dirent.d_ino = entry.ino;
-			ptr->dirent.d_type = entry.type;
-			ptr->rec_len = sizeof(DirectoryEntry) + entry.name_len + 1;
-			strcpy(ptr->dirent.d_name, entry.name);
-			ptr = ptr->next();
-		}
-
-		list->entry_count = m_entries.size() + 2;
-
-		return {};
-	}
-
-	BAN::ErrorOr<void> RamDirectoryInode::create_file_impl(BAN::StringView name, mode_t mode, uid_t uid, gid_t gid)
-	{
-		BAN::RefPtr<RamInode> inode;
-		if (Mode(mode).ifreg())
-			inode = TRY(RamFileInode::create(m_fs, mode & ~Inode::Mode::TYPE_MASK, uid, gid));
-		else
-			return BAN::Error::from_errno(ENOTSUP);
-
-		TRY(add_inode(name, inode));
-
-		return {};
-	}
-
-	BAN::ErrorOr<void> RamDirectoryInode::create_directory_impl(BAN::StringView name, mode_t mode, uid_t uid, gid_t gid)
-	{
-		if (!Mode(mode).ifdir())
-			return BAN::Error::from_errno(EINVAL);
-		auto inode = TRY(RamDirectoryInode::create(m_fs, ino(), mode & ~Inode::Mode::TYPE_MASK, uid, gid));
-		TRY(add_inode(name, inode));
-		return {};
-	}
-
-	static uint8_t get_type(Inode::Mode mode)
-	{
-		if (mode.ifreg())
-			return DT_REG;
-		if (mode.ifdir())
-			return DT_DIR;
-		if (mode.ifchr())
-			return DT_CHR;
-		if (mode.ifblk())
-			return DT_BLK;
-		if (mode.ififo())
-			return DT_FIFO;
-		if (mode.ifsock())
-			return DT_SOCK;
-		if (mode.iflnk())
-			return DT_LNK;
-		return DT_UNKNOWN;
-	}
-
-	BAN::ErrorOr<void> RamDirectoryInode::add_inode(BAN::StringView name, BAN::RefPtr<RamInode> inode)
-	{
-		if (name.size() > m_name_max)
-			return BAN::Error::from_errno(ENAMETOOLONG);
-		
-		for (auto& entry : m_entries)
-			if (name == entry.name)
-				return BAN::Error::from_errno(EEXIST);
-		
-		TRY(m_entries.push_back({ }));
-		Entry& entry = m_entries.back();
-		strcpy(entry.name, name.data());
-		entry.name_len = name.size();
-		entry.ino = inode->ino();
-		entry.type = get_type(inode->mode());
-
-		if (auto ret = m_fs.add_inode(inode); ret.is_error())
-		{
-			m_entries.pop_back();
-			return ret.release_error();
-		}
-
-		return {};
-	}
-
-	BAN::ErrorOr<void> RamDirectoryInode::unlink_impl(BAN::StringView name)
-	{
-		// FIXME: delete inodes contents only after they are closed
-		for (size_t i = 0; i < m_entries.size(); i++)
-		{
-			if (name == m_entries[i].name)
-			{
-				m_entries.remove(i);
-				return {};
-			}
-		}
-		return BAN::Error::from_errno(ENOENT);
-	}
-
-	/*
-
-		RAM SYMLINK INODE
-
-	*/
-
-	BAN::ErrorOr<BAN::RefPtr<RamSymlinkInode>> RamSymlinkInode::create(RamFileSystem& fs, BAN::StringView target_sv, mode_t mode, uid_t uid, gid_t gid)
-	{
-		FullInodeInfo inode_info(fs, mode, uid, gid);
-
-		BAN::String target_str;
-		TRY(target_str.append(target_sv));
-
-		auto* ram_inode = new RamSymlinkInode(fs, inode_info, BAN::move(target_str));
-		if (ram_inode == nullptr)
-			return BAN::Error::from_errno(ENOMEM);
-		return BAN::RefPtr<RamSymlinkInode>::adopt(ram_inode);
-	}
-
-	RamSymlinkInode::RamSymlinkInode(RamFileSystem& fs, const FullInodeInfo& inode_info, BAN::String&& target)
-		: RamInode(fs, inode_info)
-		, m_target(BAN::move(target))
-	{
-		m_inode_info.mode |= Inode::Mode::IFLNK;
-	}
-
-	BAN::ErrorOr<BAN::String> RamSymlinkInode::link_target_impl()
-	{
-		BAN::String result;
-		TRY(result.append(m_target));
-		return result;
-	}
-
-	BAN::ErrorOr<void> RamSymlinkInode::set_link_target(BAN::StringView target)
-	{
-		BAN::String temp;
-		TRY(temp.append(target));
-		m_target = BAN::move(temp);
-		return {};
-	}
-
-}

kernel/kernel/FS/TmpFS/FileSystem.cpp

@@ -6,6 +6,9 @@ namespace Kernel
 
 	BAN::ErrorOr<TmpFileSystem*> TmpFileSystem::create(size_t max_pages, mode_t mode, uid_t uid, gid_t gid)
 	{
+		if (max_pages < 2)
+			return BAN::Error::from_errno(ENOSPC);
+
 		auto* result = new TmpFileSystem(max_pages);
 		if (result == nullptr)
 			return BAN::Error::from_errno(ENOMEM);
@@ -22,6 +25,8 @@ namespace Kernel
 		paddr_t data_paddr = Heap::get().take_free_page();
 		if (data_paddr == 0)
 			return BAN::Error::from_errno(ENOMEM);
+		m_used_pages++;
+
 		m_data_pages.set_paddr(data_paddr);
 		m_data_pages.set_flags(PageInfo::Flags::Present);
 		PageTable::with_fast_page(data_paddr, [&] {
@@ -31,6 +36,8 @@ namespace Kernel
 		paddr_t inodes_paddr = Heap::get().take_free_page();
 		if (inodes_paddr == 0)
 			return BAN::Error::from_errno(ENOMEM);
+		m_used_pages++;
+
 		m_inode_pages.set_paddr(inodes_paddr);
 		m_inode_pages.set_flags(PageInfo::Flags::Present);
 		PageTable::with_fast_page(inodes_paddr, [&] {
@@ -49,6 +56,8 @@ namespace Kernel
 
 	BAN::ErrorOr<BAN::RefPtr<TmpInode>> TmpFileSystem::open_inode(ino_t ino)
 	{
+		LockGuard _(m_lock);
+
 		if (m_inode_cache.contains(ino))
 			return m_inode_cache[ino];
 
@@ -66,6 +75,8 @@ namespace Kernel
 
 	BAN::ErrorOr<void> TmpFileSystem::add_to_cache(BAN::RefPtr<TmpInode> inode)
 	{
+		LockGuard _(m_lock);
+
 		if (!m_inode_cache.contains(inode->ino()))
 			TRY(m_inode_cache.insert(inode->ino(), inode));
 		return {};
@@ -73,12 +84,16 @@ namespace Kernel
 
 	void TmpFileSystem::remove_from_cache(BAN::RefPtr<TmpInode> inode)
 	{
+		LockGuard _(m_lock);
+	
 		ASSERT(m_inode_cache.contains(inode->ino()));
 		m_inode_cache.remove(inode->ino());
 	}
 
 	void TmpFileSystem::read_inode(ino_t ino, TmpInodeInfo& out)
 	{
+		LockGuard _(m_lock);
+
 		auto inode_location = find_inode(ino);
 		PageTable::with_fast_page(inode_location.paddr, [&] {
 			out = PageTable::fast_page_as_sized<TmpInodeInfo>(inode_location.index);
@@ -87,6 +102,8 @@ namespace Kernel
 
 	void TmpFileSystem::write_inode(ino_t ino, const TmpInodeInfo& info)
 	{
+		LockGuard _(m_lock);
+
 		auto inode_location = find_inode(ino);
 		PageTable::with_fast_page(inode_location.paddr, [&] {
 			auto& inode_info = PageTable::fast_page_as_sized<TmpInodeInfo>(inode_location.index);
@@ -96,6 +113,8 @@ namespace Kernel
 
 	void TmpFileSystem::delete_inode(ino_t ino)
 	{
+		LockGuard _(m_lock);
+
 		auto inode_location = find_inode(ino);
 		PageTable::with_fast_page(inode_location.paddr, [&] {
 			auto& inode_info = PageTable::fast_page_as_sized<TmpInodeInfo>(inode_location.index);
@@ -109,6 +128,8 @@ namespace Kernel
 
 	BAN::ErrorOr<ino_t> TmpFileSystem::allocate_inode(const TmpInodeInfo& info)
 	{
+		LockGuard _(m_lock);
+
 		constexpr size_t inodes_per_page = PAGE_SIZE / sizeof(TmpInodeInfo);
 
 		ino_t ino = first_inode;
@@ -133,6 +154,8 @@ namespace Kernel
 
 	TmpFileSystem::InodeLocation TmpFileSystem::find_inode(ino_t ino)
 	{
+		LockGuard _(m_lock);
+
 		ASSERT_GTE(ino, first_inode);
 		ASSERT_LT(ino, max_inodes);
 
@@ -149,6 +172,8 @@ namespace Kernel
 
 	void TmpFileSystem::free_block(size_t index)
 	{
+		LockGuard _(m_lock);
+
 		constexpr size_t addresses_per_page = PAGE_SIZE / sizeof(PageInfo);
 
 		const size_t index_of_page = (index - first_data_page) / addresses_per_page;
@@ -160,6 +185,8 @@ namespace Kernel
 			auto& page_info = PageTable::fast_page_as_sized<PageInfo>(index_in_page);
 			ASSERT(page_info.flags() & PageInfo::Flags::Present);
 			Heap::get().release_page(page_info.paddr());
+			m_used_pages--;
+
 			page_info.set_paddr(0);
 			page_info.set_flags(0);
 		});
@@ -167,6 +194,8 @@ namespace Kernel
 
 	BAN::ErrorOr<size_t> TmpFileSystem::allocate_block()
 	{
+		LockGuard _(m_lock);
+
 		size_t result = first_data_page;
 		TRY(for_each_indirect_paddr_allocating(m_data_pages, [&] (paddr_t paddr, bool allocated) {
 			if (allocated)
@@ -179,12 +208,16 @@ namespace Kernel
 
 	paddr_t TmpFileSystem::find_block(size_t index)
 	{
+		LockGuard _(m_lock);
+
 		ASSERT_GT(index, 0);
 		return find_indirect(m_data_pages, index - first_data_page, 3);
 	}
 
 	paddr_t TmpFileSystem::find_indirect(PageInfo root, size_t index, size_t depth)
 	{
+		LockGuard _(m_lock);
+
 		ASSERT(root.flags() & PageInfo::Flags::Present);
 		if (depth == 0)
 		{
@@ -214,6 +247,8 @@ namespace Kernel
 	template<TmpFuncs::for_each_indirect_paddr_allocating_callback F>
 	BAN::ErrorOr<BAN::Iteration> TmpFileSystem::for_each_indirect_paddr_allocating_internal(PageInfo page_info, F callback, size_t depth)
 	{
+		LockGuard _(m_lock);
+
 		ASSERT(page_info.flags() & PageInfo::Flags::Present);
 		if (depth == 0)
 		{
@@ -230,9 +265,12 @@ namespace Kernel
 
 			if (!(next_info.flags() & PageInfo::Flags::Present))
 			{
+				if (m_used_pages >= m_max_pages)
+					return BAN::Error::from_errno(ENOSPC);
 				paddr_t new_paddr = Heap::get().take_free_page();
 				if (new_paddr == 0)
 					return BAN::Error::from_errno(ENOMEM);
+				m_used_pages++;
 
 				PageTable::with_fast_page(new_paddr, [&] {
 					memset(PageTable::fast_page_as_ptr(), 0x00, PAGE_SIZE);
@@ -268,6 +306,8 @@ namespace Kernel
 	template<TmpFuncs::for_each_indirect_paddr_allocating_callback F>
 	BAN::ErrorOr<void> TmpFileSystem::for_each_indirect_paddr_allocating(PageInfo page_info, F callback, size_t depth)
 	{
+		LockGuard _(m_lock);
+
 		BAN::Iteration result = TRY(for_each_indirect_paddr_allocating_internal(page_info, callback, depth));
 		ASSERT(result == BAN::Iteration::Break);
 		return {};

kernel/kernel/FS/TmpFS/Inode.cpp

@@ -215,6 +215,86 @@ namespace Kernel
 		return {};
 	}
 
+	/* SYMLINK INODE */
+
+	BAN::ErrorOr<BAN::RefPtr<TmpSymlinkInode>> TmpSymlinkInode::create_new(TmpFileSystem& fs, mode_t mode, uid_t uid, gid_t gid, BAN::StringView target)
+	{
+		auto info = create_inode_info(Mode::IFLNK | mode, uid, gid);
+		ino_t ino = TRY(fs.allocate_inode(info));
+
+		auto* inode_ptr = new TmpSymlinkInode(fs, ino, info);
+		if (inode_ptr == nullptr)
+			return BAN::Error::from_errno(ENOMEM);
+		auto inode = BAN::RefPtr<TmpSymlinkInode>::adopt(inode_ptr);
+
+		TRY(inode->set_link_target(target));
+
+		return inode;
+	}
+
+	TmpSymlinkInode::TmpSymlinkInode(TmpFileSystem& fs, ino_t ino, const TmpInodeInfo& info)
+		: TmpInode(fs, ino, info)
+	{
+		ASSERT(mode().iflnk());
+	}
+
+	TmpSymlinkInode::~TmpSymlinkInode()
+	{
+	}
+
+	BAN::ErrorOr<void> TmpSymlinkInode::set_link_target(BAN::StringView new_target)
+	{
+		free_all_blocks();
+		m_inode_info.size = 0;
+
+		if (new_target.size() <= sizeof(TmpInodeInfo::block))
+		{
+			memcpy(m_inode_info.block.data(), new_target.data(), new_target.size());
+			m_inode_info.size = new_target.size();
+			return {};
+		}
+
+		const size_t blocks_needed = BAN::Math::div_round_up<size_t>(new_target.size(), blksize());
+		for (size_t i = 0; i < blocks_needed; i++)
+		{
+			const size_t block_index = TRY(block_index_with_allocation(i));
+			const size_t byte_count = BAN::Math::min<size_t>(new_target.size() - i * blksize(), blksize());
+
+			m_fs.with_block_buffer(block_index, [&](BAN::ByteSpan bytespan) {
+				memcpy(bytespan.data(), new_target.data() + i * blksize(), byte_count);
+			});
+
+			m_inode_info.size += byte_count;
+		}
+
+		return {};
+	}
+
+	BAN::ErrorOr<BAN::String> TmpSymlinkInode::link_target_impl()
+	{
+		BAN::String result;
+		TRY(result.resize(size()));
+
+		if ((size_t)size() <= sizeof(TmpInodeInfo::block))
+		{
+			memcpy(result.data(), m_inode_info.block.data(), size());
+			return result;
+		}
+
+		const size_t data_block_count = BAN::Math::div_round_up<size_t>(size(), blksize());
+		for (size_t i = 0; i < data_block_count; i++)
+		{
+			const size_t block_index = TRY(block_index_with_allocation(i));
+			const size_t byte_count = BAN::Math::min<size_t>(size() - i * blksize(), blksize());
+
+			m_fs.with_block_buffer(block_index, [&](BAN::ByteSpan bytespan) {
+				memcpy(result.data() + i * blksize(), bytespan.data(), byte_count);
+			});
+		}
+
+		return result;
+	}
+
 	/* DIRECTORY INODE */
 
 	BAN::ErrorOr<BAN::RefPtr<TmpDirectoryInode>> TmpDirectoryInode::create_root(TmpFileSystem& fs, mode_t mode, uid_t uid, gid_t gid)

kernel/kernel/Input/PS2Controller.cpp

@@ -180,18 +180,24 @@ namespace Kernel::Input
 			m_devices[0]->set_irq(PS2::IRQ::DEVICE0);
 			m_devices[0]->enable_interrupt();
 			config |= PS2::Config::INTERRUPT_FIRST_PORT;
-			DevFileSystem::get().add_device(m_devices[0]);
 		}
 		if (m_devices[1])
 		{
 			m_devices[1]->set_irq(PS2::IRQ::DEVICE1);
 			m_devices[1]->enable_interrupt();
 			config |= PS2::Config::INTERRUPT_SECOND_PORT;
-			DevFileSystem::get().add_device(m_devices[1]);
 		}
 
 		controller_send_command(PS2::Command::WRITE_CONFIG, config);
-			
+
+		for (uint8_t device = 0; device < 2; device++)
+		{
+			if (m_devices[device] == nullptr)
+				continue;
+			m_devices[device]->send_initialize();
+			DevFileSystem::get().add_device(m_devices[device]);
+		}
+
 		return {};
 	}
 

kernel/kernel/Input/PS2Keyboard.cpp

@@ -19,9 +19,6 @@ namespace Kernel::Input
 		PS2Keyboard* keyboard = new PS2Keyboard(controller);
 		if (keyboard == nullptr)
 			return BAN::Error::from_errno(ENOMEM);
-		BAN::ScopeGuard guard([keyboard] { delete keyboard; });
-		TRY(keyboard->initialize());
-		guard.disable();
 		return keyboard;
 	}
 
@@ -69,12 +66,11 @@ namespace Kernel::Input
 		}
 	}
 
-	BAN::ErrorOr<void> PS2Keyboard::initialize()
+	void PS2Keyboard::send_initialize()
 	{
 		append_command_queue(Command::SET_LEDS, 0x00);
 		append_command_queue(Command::SCANCODE, PS2::KBScancode::SET_SCANCODE_SET2);
 		append_command_queue(Command::ENABLE_SCANNING);
-		return {};
 	}
 
 	void PS2Keyboard::update()

kernel/kernel/Terminal/TTY.cpp

@@ -33,7 +33,7 @@ namespace Kernel
 		if (inode_or_error.is_error())
 		{
 			if (inode_or_error.error().get_error_code() == ENOENT)
-				DevFileSystem::get().add_inode("tty"sv, MUST(RamSymlinkInode::create(DevFileSystem::get(), s_tty->name(), 0666, 0, 0)));
+				DevFileSystem::get().add_inode("tty"sv, MUST(TmpSymlinkInode::create_new(DevFileSystem::get(), 0666, 0, 0, s_tty->name())));
 			else
 				dwarnln("{}", inode_or_error.error());
 			return;
@@ -41,7 +41,7 @@ namespace Kernel
 
 		auto inode = inode_or_error.release_value();
 		if (inode->mode().iflnk())
-			MUST(((RamSymlinkInode*)inode.ptr())->set_link_target(name()));
+			MUST(reinterpret_cast<TmpSymlinkInode*>(inode.ptr())->set_link_target(name()));
 	}
 
 	BAN::ErrorOr<void> TTY::tty_ctrl(int command, int flags)

toolchain/binutils-2.39.patch

@@ -59,7 +59,7 @@ index 62f806bdfe..e05db38382 100644
    h8300-*-elf)				fmt=elf ;;
    h8300-*-linux*)			fmt=elf em=linux ;;
  
-+  i386-*-banan_os*)			fmt=elf ;;
++  i386-*-banan_os*)			fmt=elf em=gnu ;;
    i386-*-beospe*)			fmt=coff em=pe ;;
    i386-*-beos*)				fmt=elf ;;
    i386-*-elfiamcu)			fmt=elf arch=iamcu ;;

toolchain/build.sh

@@ -74,7 +74,7 @@ build_binutils () {
 		--disable-nls \
 		--disable-werror
 
-	make -j $(nproc)
+	make
 	make install
 }
 
@@ -100,8 +100,8 @@ build_gcc () {
 		--disable-nls \
 		--enable-languages=c,c++
 
-	make -j $(nproc) all-gcc 
+	make all-gcc
-	make -j $(nproc) all-target-libgcc CFLAGS_FOR_TARGET='-g -O2 -mcmodel=large -mno-red-zone'
+	make all-target-libgcc CFLAGS_FOR_TARGET='-g -O2 -mcmodel=large -mno-red-zone'
 	make install-gcc install-target-libgcc
 }
 
@@ -127,7 +127,7 @@ build_grub () {
 		--with-platform="efi" \
 		--disable-werror
 	
-	make -j $(nproc)
+	make
 	make install
 }
 
@@ -138,7 +138,7 @@ build_libstdcpp () {
 	fi
 
 	cd $BANAN_BUILD_DIR/toolchain/$GCC_VERSION/build
-	make -j $(nproc) all-target-libstdc++-v3
+	make all-target-libstdc++-v3
 	make install-target-libstdc++-v3
 }
 
@@ -154,16 +154,22 @@ fi
 
 # NOTE: we have to manually create initial sysroot with libc headers
 #       since cmake cannot be invoked yet
-echo "Syncing sysroot headers"
+echo "Creating dummy sysroot"
-mkdir -p $BANAN_SYSROOT
+rm -rf $BANAN_SYSROOT
-sudo mkdir -p $BANAN_SYSROOT/usr/include
+mkdir -p $BANAN_SYSROOT/usr
-sudo rsync -a $BANAN_ROOT_DIR/libc/include/ $BANAN_SYSROOT/usr/include/
+cp -r $BANAN_ROOT_DIR/libc/include $BANAN_SYSROOT/usr/include
 
-mkdir -p $BANAN_BUILD_DIR/toolchain
 
 # Cleanup all old files from toolchain prefix
 rm -rf $BANAN_TOOLCHAIN_PREFIX
 
+if [[ -z ${MAKEFLAGS:x} ]]; then
+	export MAKEFLAGS="-j$(nproc)"
+fi
+
+mkdir -p $BANAN_BUILD_DIR/toolchain
 build_binutils
 build_gcc
 build_grub
+
+rm -rf $BANAN_SYSROOT