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Kernel: start work on higher half kernel

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Bananymous
2023-05-30 08:00:17 +03:00
parent 79315d318c
commit 0907965dc5
5 changed files with 65 additions and 28 deletions
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47
kernel/arch/x86_64/boot.S
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@@ -10,6 +10,9 @@
.set PG_READ_WRITE, 1<<1
.set PG_PAGE_SIZE, 1<<7
#define KERNEL_OFFSET 0xFFFFFFFF80000000
#define V2P(vaddr) ((vaddr) - KERNEL_OFFSET)
.code32
# Multiboot header
@@ -49,16 +52,23 @@
# Identity map first GiB
.align 4096
boot_pml4:
.quad boot_pdpt + (PG_READ_WRITE | PG_PRESENT)
.quad V2P(boot_pdpt_lo) + (PG_READ_WRITE | PG_PRESENT)
.rept 510
.quad 0
.endr
.quad V2P(boot_pdpt_hi) + (PG_READ_WRITE | PG_PRESENT)
boot_pdpt_lo:
.quad V2P(boot_pd) + (PG_READ_WRITE | PG_PRESENT)
.rept 511
.quad 0
.endr
boot_pdpt:
.quad boot_pd + (PG_READ_WRITE | PG_PRESENT)
.rept 511
boot_pdpt_hi:
.rept 510
.quad 0
.endr
boot_pd:
.endr
.quad V2P(boot_pd) + (PG_READ_WRITE | PG_PRESENT)
.quad 0
boot_pd: # 1 GiB
.set i, 0
.rept 512
.quad i + (PG_PAGE_SIZE | PG_READ_WRITE | PG_PRESENT)
@@ -71,7 +81,7 @@ boot_gdt:
.quad 0x00AF92000000FFFF # kernel data
boot_gdtr:
.short . - boot_gdt - 1
.quad boot_gdt
.quad V2P(boot_gdt)
has_cpuid:
pushfl
@@ -110,11 +120,11 @@ check_requirements:
copy_kernel_commandline:
pushl %esi
pushl %edi
movl g_multiboot_info, %esi
movl V2P(g_multiboot_info), %esi
addl $16, %esi
movl (%esi), %esi
movl $1024, %ecx
movl $g_kernel_cmdline, %edi
movl $V2P(g_kernel_cmdline), %edi
rep movsl
popl %edi
popl %esi
@@ -143,7 +153,7 @@ initialize_paging:
wrmsr
# set address of paging structures
movl $boot_pml4, %ecx
movl $V2P(boot_pml4), %ecx
movl %ecx, %cr3
# enable paging
@@ -157,9 +167,9 @@ initialize_paging:
.type _start, @function
_start:
# Initialize stack and multiboot info
movl $g_boot_stack_top, %esp
movl %eax, g_multiboot_magic
movl %ebx, g_multiboot_info
movl $V2P(g_boot_stack_top), %esp
movl %eax, V2P(g_multiboot_magic)
movl %ebx, V2P(g_multiboot_info)
call copy_kernel_commandline
call check_requirements
@@ -168,8 +178,8 @@ _start:
call initialize_paging
# flush gdt and jump to 64 bit
lgdt boot_gdtr
ljmpl $0x08, $long_mode
lgdt V2P(boot_gdtr)
ljmpl $0x08, $V2P(long_mode)
.code64
long_mode:
@@ -183,6 +193,13 @@ long_mode:
movw %ax, %fs
movw %ax, %gs
# jump to higher half
movq $g_boot_stack_top, %rsp
movabsq $higher_half, %rcx
jmp *%rcx
higher_half:
# call global constuctors
call _init