KolibriOS/kolibrios64
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draft of mapping kernel to VIRT_KERNEL_BASE

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rgimad
2025-02-25 15:33:26 +03:00
parent 5ccef2931b
commit 0c16a5f65a
1 changed files with 64 additions and 19 deletions
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83
kernel/boot/bootx64.asm
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@@ -21,7 +21,9 @@ include '../const.inc'
purge DQ ; because of some struct DQ in const.inc purge DQ ; because of some struct DQ in const.inc
include 'uefi64.inc' include 'uefi64.inc'
MEMORY_MAP_SIZE = 0x10000 MEMORY_MAP_SIZE = 0x10000 ; NOTE: can be bigger?
VIRT_KERNEL_BASE = 0xFFFFFFFF80000000
; linux/arch/x86/include/uapi/asm/e820.h ; linux/arch/x86/include/uapi/asm/e820.h
E820_RAM = 1 E820_RAM = 1
@@ -341,6 +343,7 @@ proc main _efi_handle, _efi_table
shl rcx, BSF 4096 shl rcx, BSF 4096
add rcx, rax add rcx, rax
mov [rax + KERNEL64_HEADER.phys_end], rcx mov [rax + KERNEL64_HEADER.phys_end], rcx
mov [kernel_image_phys_end], rcx
fstcall efi_puts, "Kernel + kernel_stack loaded to phys region [" fstcall efi_puts, "Kernel + kernel_stack loaded to phys region ["
fstcall efi_print_hex_fixed, [rax + KERNEL64_HEADER.phys_start] fstcall efi_print_hex_fixed, [rax + KERNEL64_HEADER.phys_start]
@@ -348,25 +351,60 @@ proc main _efi_handle, _efi_table
fstcall efi_print_hex_fixed, [rax + KERNEL64_HEADER.phys_end] fstcall efi_print_hex_fixed, [rax + KERNEL64_HEADER.phys_end]
fstcall efi_puts, <")",13,10,0> fstcall efi_puts, <")",13,10,0>
; TODO ; Zero out the paging tables p1-p4
;; pass phys start / end to kernel header mov rdi, table_p1
;; map [kernel_phys_start; kernel_phys_end) to 0xFFFFFFFF80000000, set kernel rsp, jmp to k64_entry mov rcx, 512*4
;; NOTE: dont allocate after getting memmap bc uefi allocations change the memmap. => get memmmap last of all xor rax, rax
;; TODO: write memmap to some buffer, to pass it to the kernel. move getting memmap code to a separate function cld
rep stosq
; mov rax, [kernel_file_size_pages] ; P4[P4_OFFSET(VIRT_KERNEL_BASE)] = P3 or flags
; shl rax, BSF 4096 ; * 4096 mov rax, table_p3
; add rax, [kernel_image_phys_base] or rax, 0x3 ; present, r/w
; ; fstcall efi_print_hex_fixed, rax mov rdi, table_p4
; ; jmp $ add rdi, ((VIRT_KERNEL_BASE shr 39) and 0x1FF)*8 ; offset of entry in P4
; push efi_puts stosq
; push efi_print_hex_fixed
; mov rsp, rax ; P3[P3_OFFSET(VIRT_KERNEL_BASE)] = P2 or flags
; mov rax, [kernel_header_buf + KERNEL64_HEADER.entry_point_offset] mov rax, table_p2
; add rax, [kernel_image_phys_base] or rax, 0x3 ; present, r/w
; ; fstcall efi_print_hex_fixed, rax mov rdi, table_p3
; ; jmp $ add rdi, ((VIRT_KERNEL_BASE shr 30) and 0x1FF)*8
; jmp rax stosq
; P2[P2_OFFSET(VIRT_KERNEL_BASE)] = P1 or flags
mov rax, table_p1
or rax, 0x3 ; present, r/w
mov rdi, table_p2
add rdi, ((VIRT_KERNEL_BASE shr 21) and 0x1FF)*8
stosq
mov rcx, [kernel_image_phys_base]
mov rdx, VIRT_KERNEL_BASE
.fill_p1:
mov rax, rdx
shr rax, 12
and rax, 0x1FF
shl rax, BSF 8 ; *8
add rax, table_p1
mov rdi, rcx
or rdi, 0x3
mov [rax], rdi
add rcx, 4096
add rdx, 4096
cmp rcx, [kernel_image_phys_end]
jb .fill_p1
; TODO
;; put phys start / end into kernel header
;; map [kernel_phys_start; kernel_phys_end) to 0xFFFFFFFF80000000
;; (~~fill paging tables~~, ExitBootServices and switch to the new PML4), set kernel rsp, jmp to k64_entry
;; NOTE: dont allocate after getting memmap bc uefi allocations change the memmap. => perform GetMemoryMap last of all..
;; QUESTION: How to pass memory map to the kernel?
;; Push in contents in stack? (wtf). Write memmap to some buffer,
;; map it into kernel address space and push pointer to it into the kernel stack
;; getting memmap should be a separate function
;;;;;;;;;;;;;;;;; test output ;;;;;;;;;;;;;;;;; test output
@@ -477,6 +515,13 @@ kernel_stack_size_pages dq ?
kernel_image_total_pages dq ? kernel_image_total_pages dq ?
kernel_image_phys_base dq ? kernel_image_phys_base dq ?
kernel_image_phys_end dq ?
align 4096
table_p4 rq 512
table_p3 rq 512
table_p2 rq 512
table_p1 rq 512