convert MBR, VBR, & Stage2 to use a BSS section. #3

Merged
Nivirx merged 25 commits from bss-setup into trunk 2024-10-13 18:05:19 -04:00
2 changed files with 11 additions and 28 deletions
Showing only changes of commit d1217182d4 - Show all commits

View File

@@ -25,14 +25,11 @@
[WARNING -reloc-abs-word] ; Yes, we use absolute addresses. surpress these warnings. [WARNING -reloc-abs-word] ; Yes, we use absolute addresses. surpress these warnings.
[map all mbr.map] [map all mbr.map]
%define __STEVIA_MBR %define __STEVIA_MBR
jmp short (init - $$) jmp short (init - $$)
nop nop
; ############### ; ###############
;
; Headers/Includes/Definitions ; Headers/Includes/Definitions
;
; ############### ; ###############
%include "util/bochs_magic.inc" %include "util/bochs_magic.inc"
@@ -43,11 +40,7 @@ nop
%include "error_codes.inc" %include "error_codes.inc"
%include "partition_table.inc" %include "partition_table.inc"
; ############### ALIGN 4
; End Section
; ###############
ALIGN 4, db 0x90
init: init:
cli ; We do not want to be interrupted cli ; We do not want to be interrupted
@@ -69,23 +62,15 @@ init:
jmp 0:main jmp 0:main
; ############### ; ###############
;
; Extra/Shared Functions ; Extra/Shared Functions
;
; ############### ; ###############
%include "util/kmem_func.nasm" %include "util/kmem_func.nasm"
%include "util/error_func.nasm" %include "util/error_func.nasm"
; ###############
; End Section
; ###############
; ;
; bp - 2 : uint8_t boot_drive ; bp - 2 : uint8_t boot_drive
; bp - 4 : uint16_t part_offset ; bp - 4 : uint16_t part_offset
;
ALIGN 4, db 0x90 ALIGN 4, db 0x90
main: main:
mov byte [bp - 2], dl ; BIOS passes drive number in DL mov byte [bp - 2], dl ; BIOS passes drive number in DL
@@ -158,7 +143,7 @@ main:
mov si, word [bp - 4] mov si, word [bp - 4]
mov dl, byte [bp - 2] mov dl, byte [bp - 2]
jmp 0:0x7C00 jmp word 0x0000:0x7C00
; ############### ; ###############
; ;
@@ -168,10 +153,6 @@ main:
%include 'BIOS/func/ext_read.nasm' %include 'BIOS/func/ext_read.nasm'
; ###############
; End Section
; ###############
%assign bytes_remaining (440 - ($ - $$)) %assign bytes_remaining (440 - ($ - $$))
%warning MBR has bytes_remaining bytes remaining for code (MAX: 440 bytes) %warning MBR has bytes_remaining bytes remaining for code (MAX: 440 bytes)
times ((512 - 72) - ($ - $$)) nop ; Fill the rest of sector with nop times ((512 - 72) - ($ - $$)) nop ; Fill the rest of sector with nop

View File

@@ -24,7 +24,7 @@
[WARNING -reloc-abs-word] [WARNING -reloc-abs-word]
[map all vbr.map] ; Yes, we use absolute addresses. surpress these warnings. [map all vbr.map] ; Yes, we use absolute addresses. surpress these warnings.
%define __STEVIA_VBR %define __STEVIA_VBR
section .text
__ENTRY: __ENTRY:
jmp short (init - $$) jmp short (init - $$)
nop nop
@@ -51,11 +51,8 @@ times 54 db 0x00
%include "error_codes.inc" %include "error_codes.inc"
%include "fat32/bpb_offset_bx.inc" %include "fat32/bpb_offset_bx.inc"
; ###############
; End Section
; ###############
ALIGN 4, db 0x90 ALIGN 4
init: init:
cli ; We do not want to be interrupted cli ; We do not want to be interrupted
@@ -85,6 +82,9 @@ init:
; End Section ; End Section
; ############### ; ###############
;
; byte boot_drive @ bp - 2
; word part_offset @ bp - 4
ALIGN 4, db 0x90 ALIGN 4, db 0x90
main: main:
mov byte [bp - 2], dl ; boot_drive mov byte [bp - 2], dl ; boot_drive
@@ -101,7 +101,7 @@ main:
push ax push ax
mov ax, fat32_bpb ; defined in memory.inc, destination mov ax, fat32_bpb ; defined in memory.inc, destination
push ax push ax
call kmemcpy ; copy bpb to memory call kmemcpy ; copy bpb & ebpb to memory
add sp, 0x6 add sp, 0x6
mov bx, fat32_bpb ; bx now points to aligned memory structure mov bx, fat32_bpb ; bx now points to aligned memory structure
@@ -130,6 +130,8 @@ main:
add sp, 0xC add sp, 0xC
.check_sig: .check_sig:
; BUG: this is hard coded to check @ ((0x7E0 << 4) + 0x7FFC)...i.e (STAGE2_ENTRY + (STAGE2_MAX_BYTES - 4))
; this should be removed or done properly
mov ax, 0x7E0 mov ax, 0x7E0
mov fs, ax mov fs, ax
cmp dword [fs:0x7FFC], 0xDEADBEEF cmp dword [fs:0x7FFC], 0xDEADBEEF
@@ -140,7 +142,7 @@ main:
.sig_ok: .sig_ok:
mov si, word [bp - 4] mov si, word [bp - 4]
mov dl, byte [bp - 2] mov dl, byte [bp - 2]
jmp 0:0x7E00 jmp word 0x0000:0x7E00
; ############### ; ###############
; Required BIOS function(s) ; Required BIOS function(s)