banan-os/bootloader/boot.S

.code16

#########################################
#
# STAGE 1 BOOTLOADER
#
# its sole purpose is to load stage2 from
# bios boot partition
#
#########################################

.section .stage1

.global stage1_main
stage1_main:
	# setup segments
	movw $0, %ax
	movw %ax, %ds
	movw %ax, %es

	# setup stack
	movw %ax, %ss
	movl $0x7C00, %esp

	# save boot disk number
	call read_stage2_into_memory

	jmp stage2_main

.global print_and_halt
print_and_halt:
	call puts
halt:
	hlt
	jmp halt


#########################################
#
# STAGE 2 BOOTLOADER
#
#########################################

.section .stage2

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 read_user_command_line

	call print_newline

	movw $start_kernel_load_msg, %si
	call puts; call print_newline

	call print_memory_map

	call find_root_disk
	call find_root_partition

	call print_root_partition_info

	jmp halt

hello_msg:
	.asciz "This is banan-os bootloader"

start_kernel_load_msg:
	.asciz "Starting to load kernel"
Bootloader: Start work on bootloader I wrote a fast first stage bootloader and a installer to put it into a disk image. 2023-11-09 22:42:47 +02:00			`.code16`

			`#########################################`
			`#`
			`# STAGE 1 BOOTLOADER`
			`#`
			`# its sole purpose is to load stage2 from`
			`# bios boot partition`
			`#`
			`#########################################`

			`.section .stage1`

Bootloader: Split bootloader into multiple files This cleans up the code since bootloader is starting to near 1k lines 2023-11-14 03:26:03 +02:00			`.global stage1_main`
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 2023-11-11 22:49:00 +02:00			`stage1_main:`
Bootloader: Start work on bootloader I wrote a fast first stage bootloader and a installer to put it into a disk image. 2023-11-09 22:42:47 +02:00			`# setup segments`
			`movw $0, %ax`
			`movw %ax, %ds`
			`movw %ax, %es`

			`# setup stack`
			`movw %ax, %ss`
Bootloader: Find root partition from GPT header 2023-11-13 18:55:48 +02:00			`movl $0x7C00, %esp`
Bootloader: Start work on bootloader I wrote a fast first stage bootloader and a installer to put it into a disk image. 2023-11-09 22:42:47 +02:00
			`# save boot disk number`
Bootloader: Split bootloader into multiple files This cleans up the code since bootloader is starting to near 1k lines 2023-11-14 03:26:03 +02:00			`call read_stage2_into_memory`
Bootloader: Find root partition from GPT header 2023-11-13 18:55:48 +02:00
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 2023-11-11 22:49:00 +02:00			`jmp stage2_main`
Bootloader: Start work on bootloader I wrote a fast first stage bootloader and a installer to put it into a disk image. 2023-11-09 22:42:47 +02:00
Bootloader: Split bootloader into multiple files This cleans up the code since bootloader is starting to near 1k lines 2023-11-14 03:26:03 +02:00			`.global print_and_halt`
Bootloader: Start work on bootloader I wrote a fast first stage bootloader and a installer to put it into a disk image. 2023-11-09 22:42:47 +02:00			`print_and_halt:`
			`call puts`
			`halt:`
			`hlt`
			`jmp halt`


			`#########################################`
			`#`
			`# STAGE 2 BOOTLOADER`
			`#`
			`#########################################`

			`.section .stage2`
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 2023-11-11 22:49:00 +02:00
Bootloader: Find root partition from GPT header 2023-11-13 18:55:48 +02:00			`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`
Bootloader: Split bootloader into multiple files This cleans up the code since bootloader is starting to near 1k lines 2023-11-14 03:26:03 +02:00			`call read_user_command_line`
Bootloader: Find root partition from GPT header 2023-11-13 18:55:48 +02:00
			`call print_newline`

			`movw $start_kernel_load_msg, %si`
			`call puts; call print_newline`

			`call print_memory_map`

			`call find_root_disk`
			`call find_root_partition`

Bootloader: Split bootloader into multiple files This cleans up the code since bootloader is starting to near 1k lines 2023-11-14 03:26:03 +02:00			`call print_root_partition_info`
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 2023-11-11 22:49:00 +02:00
			`jmp halt`
Bootloader: Start work on bootloader I wrote a fast first stage bootloader and a installer to put it into a disk image. 2023-11-09 22:42:47 +02:00
			`hello_msg:`
			`.asciz "This is banan-os bootloader"`

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 2023-11-11 22:49:00 +02:00			`start_kernel_load_msg:`
			`.asciz "Starting to load kernel"`