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Author SHA1 Message Date
460165a8d1 re-naming 2025-09-13 15:07:36 -04:00
935cbd1089 naming changes to ReadMbr/Vbr 2025-09-13 14:56:26 -04:00
7f1b4fa632 more naming changes 2025-09-13 14:51:30 -04:00
2 changed files with 39 additions and 47 deletions

View File

@@ -11,9 +11,9 @@ endstruc
; void arena_init(ArenaState *a) ; void arena_init(ArenaState *a)
; ;
arena_init: ArenaInit:
__CDECL16_PROC_ENTRY __CDECL16_PROC_ENTRY
.func: .proc:
mov ax, word [bp + 4] ; ptr to state structure mov ax, word [bp + 4] ; ptr to state structure
mov di, ax mov di, ax
@@ -25,15 +25,11 @@ arena_init:
; zero out heap area on init ; zero out heap area on init
; void* kmemset_byte(void* dst, uint8_t val, uint16_t len); ; void* kmemset_byte(void* dst, uint8_t val, uint16_t len);
; TODO: use word or qword spacing at least to speed this up ; TODO: use word or qword spacing at least to speed this up
mov ax, __ARENA_HEAP_SIZE push __ARENA_HEAP_SIZE ; len
push ax ; len push 0x0 ; val = 0
xor ax, ax push __ARENA_HEAP_START ; dst
push ax ; val = 0
mov ax, __ARENA_HEAP_START
push ax ; dst
call kmemset call kmemset
add sp, 0x6 add sp, 0x6
.endp: .endp:
__CDECL16_PROC_EXIT __CDECL16_PROC_EXIT
ret ret
@@ -43,7 +39,7 @@ arena_init:
; align x up to the nearest specified alignment (a), a should be a power of 2 ; align x up to the nearest specified alignment (a), a should be a power of 2
; (x + (a-1)) & ~(a-1) ; (x + (a-1)) & ~(a-1)
; return value in ax ; return value in ax
arena_align_up: ArenaAlignUp:
__CDECL16_PROC_ENTRY __CDECL16_PROC_ENTRY
.func: .func:
; if a == 0 return x ; if a == 0 return x
@@ -51,7 +47,7 @@ arena_align_up:
mov bx, [bp + 6] ; a mov bx, [bp + 6] ; a
test bx, bx test bx, bx
jz .endp jz .endf
; enforce power-of-two for alignment, return x ; enforce power-of-two for alignment, return x
; for example... ; for example...
@@ -69,7 +65,7 @@ arena_align_up:
mov cx, bx mov cx, bx
dec cx dec cx
test bx, cx test bx, cx
jnz .endp jnz .endf
dec bx ; a - 1 dec bx ; a - 1
@@ -80,7 +76,7 @@ arena_align_up:
and cx, bx ; and with the inverse and cx, bx ; and with the inverse
mov ax, cx ; move to ax and return mov ax, cx ; move to ax and return
.endp: .endf:
__CDECL16_PROC_EXIT __CDECL16_PROC_EXIT
ret ret
@@ -88,9 +84,9 @@ arena_align_up:
; bp-2 - current used arena (i.e 'highmark') ; bp-2 - current used arena (i.e 'highmark')
; bp-4 - aligned_ptr ; bp-4 - aligned_ptr
; bp-6 - new_end ; bp-6 - new_end
arena_alloc: ArenaAlloc:
__CDECL16_PROC_ENTRY 0x10 __CDECL16_PROC_ENTRY 0x10
.func: .proc:
; remove bytes from pool and increment mark to the new cursor location ; remove bytes from pool and increment mark to the new cursor location
; return a pointer to the begining of allocated segment ; return a pointer to the begining of allocated segment
mov bx, early_heap_state mov bx, early_heap_state
@@ -102,11 +98,10 @@ arena_alloc:
push bx ; save heap_state pointer push bx ; save heap_state pointer
mov ax, word [bp + 6] ; requested next allocation alignment
push ax push word [bp + 6] ; requested next allocation alignment
mov ax, word [bp - 2] ; current arena 'highmark' push word [bp - 2] ; current arena 'highmark'
push ax call ArenaAlignUp
call arena_align_up
add sp, 0x4 add sp, 0x4
mov word [bp - 4], ax ; save return value mov word [bp - 4], ax ; save return value
@@ -118,7 +113,7 @@ arena_alloc:
mov dx, word [bx + ArenaStateStruc_t.end] mov dx, word [bx + ArenaStateStruc_t.end]
cmp ax, dx cmp ax, dx
ja arena_alloc.error ; if our heap end is < the requested throw an error, heap is full ja .error ; if our heap end is < the requested throw an error, heap is full
; else update the mark to the new value & return the aligned pointer ; else update the mark to the new value & return the aligned pointer
; mark_delta = new_end - curr_used ; mark_delta = new_end - curr_used
@@ -140,7 +135,7 @@ arena_alloc:
arena_mark: arena_mark:
__CDECL16_PROC_ENTRY __CDECL16_PROC_ENTRY
.func: .proc:
; return the current location of the 'cursor' in the allocator ; return the current location of the 'cursor' in the allocator
ERROR STEVIA_DEBUG_UNIMPLEMENTED ERROR STEVIA_DEBUG_UNIMPLEMENTED
.endp: .endp:
@@ -149,7 +144,7 @@ arena_mark:
arena_reset_to: arena_reset_to:
__CDECL16_PROC_ENTRY __CDECL16_PROC_ENTRY
.func: .proc:
; rewind the arena to a previously marked point ; rewind the arena to a previously marked point
ERROR STEVIA_DEBUG_UNIMPLEMENTED ERROR STEVIA_DEBUG_UNIMPLEMENTED
.endp: .endp:
@@ -158,7 +153,7 @@ arena_reset_to:
arena_reset: arena_reset:
__CDECL16_PROC_ENTRY __CDECL16_PROC_ENTRY
.func: .proc:
; reset the entire heap to a fresh state ; reset the entire heap to a fresh state
ERROR STEVIA_DEBUG_UNIMPLEMENTED ERROR STEVIA_DEBUG_UNIMPLEMENTED
.endp: .endp:

View File

@@ -126,29 +126,29 @@ main:
; setup the early heap ; setup the early heap
__CDECL16_CALL_ARGS early_heap_state __CDECL16_CALL_ARGS early_heap_state
__CDECL16_CALL arena_init, 1 __CDECL16_CALL ArenaInit, 1
__CDECL16_CALL_ARGS pszHelloPrompt __CDECL16_CALL_ARGS pszHelloPrompt
__CDECL16_CALL PrintString, 1 __CDECL16_CALL PrintString, 1
; setup and store our vbr/mbr (e)bpb ; setup and store our vbr/mbr (e)bpb
__CDECL16_CALL_ARGS 0x200, 0x10 __CDECL16_CALL_ARGS 0x200, 0x10
__CDECL16_CALL arena_alloc, 2 __CDECL16_CALL ArenaAlloc, 2
mov word [mbr_ptr], ax mov word [mbr_ptr], ax
push ax ; dst push ax ; dst
movzx ax, byte [u8_BootDrive] movzx ax, byte [u8_BootDrive]
push ax ; boot_drive push ax ; boot_drive
__CDECL16_CALL read_mbr, 2 ; fill mbr buffer __CDECL16_CALL ReadMbrData, 2 ; fill mbr buffer
__CDECL16_CALL_ARGS 0x200, 0x10 __CDECL16_CALL_ARGS 0x200, 0x10
__CDECL16_CALL arena_alloc, 2 __CDECL16_CALL ArenaAlloc, 2
mov word [vbr_ptr], ax mov word [vbr_ptr], ax
push ax ; dst push ax ; dst
movzx ax, byte [u8_BootDrive] movzx ax, byte [u8_BootDrive]
push ax ; boot_drive push ax ; boot_drive
__CDECL16_CALL read_vbr, 2 ; fill vbr buffer __CDECL16_CALL ReadVbrData, 2 ; fill vbr buffer
; enable A20 gate ; enable A20 gate
call EnableA20 call EnableA20
@@ -199,7 +199,7 @@ hcf:
; int read_mbr(int boot_drive, void* dst) ; int read_mbr(int boot_drive, void* dst)
; destination buffer needs 512 bytes of space ; destination buffer needs 512 bytes of space
read_mbr: ReadMbrData:
__CDECL16_PROC_ENTRY __CDECL16_PROC_ENTRY
.proc: .proc:
; read mbr on boot drive to memory (for the partition table) ; read mbr on boot drive to memory (for the partition table)
@@ -213,11 +213,10 @@ read_mbr:
push __STAGE2_SEGMENT ; this segment push __STAGE2_SEGMENT ; this segment
call read_disk_raw call read_disk_raw
add sp, 0xC add sp, 0xC
.check_sig: .check_sig:
mov bx, [bp + 6] mov bx, [bp + 6]
cmp word [bx + 0x1FE], 0xAA55 ; check for bytes at end cmp word [bx + 0x1FE], 0xAA55 ; check for bytes at end
jne read_mbr.error jne ReadMbrData.error
; TODO: this needs error checking, zero checking, check the sig a bunch of stuff... ; TODO: this needs error checking, zero checking, check the sig a bunch of stuff...
.update_globals: .update_globals:
mov ax, [bp + 6] mov ax, [bp + 6]
@@ -230,22 +229,20 @@ read_mbr:
ERROR STEVIA_DEBUG_ERR ERROR STEVIA_DEBUG_ERR
; int read_vbr(int boot_drive, void* buf) ; int read_vbr(int boot_drive, void* buf)
read_vbr: ; read vbr on boot partition to memory (for fat bpb/ebpb)
ReadVbrData:
__CDECL16_PROC_ENTRY __CDECL16_PROC_ENTRY
.proc: .proc:
__BOCHS_MAGIC_DEBUG mov bx, word [part_table_ptr] ; calculate offset; base pointer @ partition table
; read vbr on boot partition to memory (for fat bpb/ebpb)
.calc_part_offset:
mov bx, word [part_table_ptr] ; base pointer @ partition table
mov cx, 4 ; only checking 4 entries mov cx, 4 ; only checking 4 entries
mov si, PartEntry_t.attributes mov si, PartEntry_t.attributes
.find_active_L0: .find_active_L0:
mov al, byte [bx + si] mov al, byte [bx + si]
test al, 0x80 ; 0x80 == 1000_0000b test al, 0x80 ; 0x80 == 1000_0000b
je read_vbr.active_found je ReadVbrData.active_found
add si, 0x10 ; add 16 bytes to offset (next part entry's attributes) add si, 0x10 ; add 16 bytes to offset (next part entry's attributes)
loop read_vbr.find_active_L0 loop ReadVbrData.find_active_L0
jmp read_vbr.error jmp ReadVbrData.error
.active_found: .active_found:
add bx, si ; update base to active part add bx, si ; update base to active part
@@ -264,10 +261,10 @@ read_vbr:
.check_sig: .check_sig:
mov bx, [bp + 6] mov bx, [bp + 6]
cmp word [bx + 0x1FE], 0xAA55 ; check for bytes at end cmp word [bx + 0x1FE], 0xAA55 ; check for bytes at end
jne read_mbr.error jne ReadVbrData.error
.check_FAT_size: .check_FAT_size:
test word [bx + FAT32_bpb_t.unused2_ZERO_word], 0 ; TotSectors16 will not be set if FAT32 test word [bx + FAT32_bpb_t.unused2_ZERO_word], 0 ; TotSectors16 will not be set if FAT32
jnz read_vbr.error jnz ReadVbrData.error
.update_globals: .update_globals:
mov word [fat32_bpb_ptr], bx mov word [fat32_bpb_ptr], bx
add bx, FAT32_bpb_t_size ; offset to ebpb add bx, FAT32_bpb_t_size ; offset to ebpb
@@ -338,7 +335,7 @@ ALIGN 4, db 0x90
EnterUnrealMode: EnterUnrealMode:
__CDECL16_PROC_ENTRY __CDECL16_PROC_ENTRY
cli ; no interrupts cli ; no interrupts
.func: .proc:
lgdt [((__STAGE2_SEGMENT << 4) + UnrealGdtInfo)] ; load unreal gdt lgdt [((__STAGE2_SEGMENT << 4) + UnrealGdtInfo)] ; load unreal gdt
mov eax, cr0 mov eax, cr0
@@ -480,19 +477,19 @@ Gdt32Start:
Gdt32End: Gdt32End:
align 16,db 0 align 16,db 0
BUILD_NASM_VER: BuildNasmVer:
db "Stevia Stage2 built with NASM - ", __NASM_VER__, 00h db "Stevia Stage2 built with NASM - ", __NASM_VER__, 00h
align 16,db 0 align 16,db 0
BUILD_DATETIME: BuildDateTime:
db 'Assembled - ', __DATE__, ' ', __TIME__, 00h db 'Assembled - ', __DATE__, ' ', __TIME__, 00h
align 16,db 0 align 16,db 0
BUILD_GIT_VER: BuildGitVer:
db __GIT_VER__, 00h db __GIT_VER__, 00h
align 16,db 0 align 16,db 0
BUILD_GIT_HASH: BuildGitHash:
db __GIT_HASH__, 00h db __GIT_HASH__, 00h
end_data: end_data: