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Merge upstream changes from branch 'trunk' into fat32_sys_rewrite

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This commit is contained in:
Elaina Claus
2024-12-19 20:09:48 -05:00
parent d98786072c 56b86fe12e
commit 9918f2367e
4 changed files with 102 additions and 81 deletions
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114
src/stage2/stage2.nasm
View File

@@ -49,15 +49,20 @@
section .text
begin_text:
; dl = byte boot_drive
; si = word part_offset (active partition offset)
; bx = ptr PartTable_t partition_table
; dx = ptr FAT32_bpb_t fat32_bpb
; ax = word part_offset (active partition offset)
; si = ptr PartTable_t partition_table
; di = ptr FAT32_bpb_t fat32_bpb
ALIGN 4, db 0x90
init:
__BOCHS_MAGIC_DEBUG
cli ; We do not want to be interrupted
mov ax, __STAGE2_SEGMENT ; set all our segments to the configured segment, excep es
; these 4 are stored in the .data section and are effectivly const types
mov [vbr_part_table_ptr], si ; pointer to partition_table
mov [vbr_fat32_bpb_ptr], di ; pointer to fat32_bpb
mov [boot_drive], dl ; copy boot_drive to globals
mov [partition_offset], ax ; copy partition_offset to globals
mov ax, __STAGE2_SEGMENT ; set all our segments to the configured segment, except es
mov ds, ax ; *
mov fs, ax ; *
mov gs, ax ; *
@@ -81,7 +86,7 @@ init:
mov sp, stack_top
mov bp, sp
sub sp, 0x20
sub sp, 0x10
push bp ; setup a somewhat normal stack frame, minus a ret ptr
sti
@@ -121,14 +126,9 @@ struc EarlyBootStruct_t
.fat32_ebpb resb FAT32_ebpb_t_size
endstruc
; bp - 4 : ptr PartTable_t partition_table
; bp - 8 : ptr FAT32_bpb_t fat32_bpb
ALIGN 4, db 0x90
main:
mov byte [boot_drive], dl ; boot_drive (probably 0x80)
mov word [partition_offset], si ; partition_offset
mov word [bp - 4], bx ; partition_table_vbr
mov word [bp - 8], dx ; fat32_bpb_vbr
__BOCHS_MAGIC_DEBUG
.check_sig:
mov eax, dword [STAGE2_SIG]
cmp eax, 0xDEADBEEF
@@ -136,21 +136,21 @@ main:
ERROR STAGE2_SIGNATURE_MISSING
.stage2_main:
mov ax, PartTable_t_size
push ax ; len = PartTable_t_size
mov ax, word [vbr_part_table_ptr] ; src = ptr to vbr partition_table
push ax
mov ax, [bp - 4] ; ptr partition_table
mov ax, partition_table ; dst
push ax
mov ax, partition_table
push ax
call kmemcpy ; copy partition table data
call kmemcpy ; copy partition table data to .data section in stage2
add sp, 0x6
mov ax, (FAT32_bpb_t_size + FAT32_ebpb_t_size) ; size in byte
mov ax, (FAT32_bpb_t_size + FAT32_ebpb_t_size) ; len
push ax
mov ax, [bp - 8]
mov ax, word [vbr_fat32_bpb_ptr] ; src
push ax
mov ax, fat32_bpb ; defined in memory.inc, destination
mov ax, fat32_bpb ; dst
push ax
call kmemcpy ; copy bpb & ebpb to memory
call kmemcpy ; copy bpb & ebpb to memory
add sp, 0x6
call SetTextMode
@@ -161,13 +161,15 @@ main:
call EnableA20
print_string A20_Enabled_OK_info
; get system memory map
call GetMemoryMap
print_string MemoryMap_OK_info
; enter unreal mode
call EnterUnrealMode
print_string UnrealMode_OK_info
; get system memory map
call GetMemoryMap
print_string MemoryMap_OK_info
; FAT Driver setup
call InitFATDriver
@@ -389,12 +391,52 @@ define_info NextFATCluster, "Attempting to find next FAT cluster..."
define_info ReadFATCluster, "Attempting to load next FAT"
define_info MaybeFound_Boot, "Maybe found a file...checking..."
define_cstr BootTarget, "BOOT BIN"
define_cstr BootTarget_cstr, "BOOT BIN"
ALIGN 16, db 0
BootTarget_str:
BootTarget:
db 'BOOT BIN'
;
; pre-bss init globals (generally const...but there are exceptions)
;
align 8, db 0x00
boot_drive:
db 0x00
align 8, db 0x00
partition_offset:
dw 0x0000
align 8, db 0x00
vbr_fat32_bpb_ptr:
dw 0x0000
align 8, db 0x00
vbr_part_table_ptr:
dw 0x0000
;
; pre-bss init globals (generally const...but there are exceptions)
;
align 8, db 0x00
boot_drive:
db 0x00
align 8, db 0x00
partition_offset:
dw 0x0000
align 8, db 0x00
vbr_fat32_bpb_ptr:
dw 0x0000
align 8, db 0x00
vbr_part_table_ptr:
dw 0x0000
ALIGN 16
IntToHex_table:
db '0123456789ABCDEF'
@@ -489,37 +531,29 @@ section .bss follows=.sign
begin_bss:
; structures
align 16, resb 1
align 8, resb 1
partition_table resb PartTable_t_size
align 16, resb 1
align 8, resb 1
fat32_bpb resb FAT32_bpb_t_size
fat32_ebpb resb FAT32_ebpb_t_size
align 16, resb 1
align 8, resb 1
fat32_nc_data resb 16
align 16, resb 1
align 8, resb 1
lba_packet resb LBAPkt_t_size
align 16, resb 1
align 8, resb 1
fat32_state:
resb FAT32_State_t_size
align 16, resb 1
align 8, resb 1
SteviaInfo:
resd 4
;
; locals
; post-bss init globals
;
ALIGN 4,resb 1
boot_drive:
resb 1
ALIGN 4,resb 1
partition_offset:
resw 1
;
; large continuous allocations

8
src/vbr/vbr.nasm
View File

@@ -152,10 +152,10 @@ main:
call read_disk_raw
add sp, 0xC
.enter_stage2:
mov dl, byte [bp - 2] ; boot_drive
mov si, word [bp - 4] ; part_offset
mov bx, partition_table
mov dx, fat32_bpb
mov dl, byte [bp - 2] ; byte boot_drive
mov ax, word [bp - 4] ; word part_offset
mov si, partition_table ; ptr partition_table
mov di, fat32_bpb ; ptr fat32_bpb
jmp word 0x0000:STAGE2_ENTRY
; ###############