diff --git a/src/stage2/stage2.nasm b/src/stage2/stage2.nasm index fb59ec1..998699b 100755 --- a/src/stage2/stage2.nasm +++ b/src/stage2/stage2.nasm @@ -37,6 +37,7 @@ nop ; ; ############### +%include "util/bochs_magic.inc" %include "cdecl16.inc" %include "entry.inc" %include "config.inc" @@ -82,78 +83,53 @@ init: ; ; bp - 2 : uint8_t boot_drive ; bp - 4 : uint16_t part_offset -; +ALIGN 4, db 0x90 main: lea ax, [bp - 2] mov [boot_drive_ptr], ax lea ax, [bp - 4] - mov [partition_offset_ptr], ax + mov [partition_offset_ptr], ax ; setup pointers to boot_drive and partition offset on stack + mov byte [bp - 2], dl ; boot_drive (probably 0x80) mov word [bp - 4], si ; partition_offset mov eax, dword [STAGE2_SIG] cmp eax, 0xDEADBEEF je main.signature_present - ERROR STAGE2_SIGNATURE_MISSING .signature_present: call SetTextMode call disable_cursor - - lea ax, [HelloPrompt_cstr] - push ax - call PrintString - add sp, 0x2 - + __PRINT_CSTR HelloPrompt + ; enable A20 gate call EnableA20 - - lea ax, [A20_Enabled_cstr] - push ax - call PrintString - add sp, 0x2 + __PRINT_CSTR A20_Enabled ; enter unreal mode call EnterUnrealMode - - lea ax, [UnrealMode_OK_cstr] - push ax - call PrintString - add sp, 0x2 + __PRINT_CSTR UnrealMode_OK ; get system memory map call GetMemoryMap - - lea ax, [MemoryMap_OK_cstr] - push ax - call PrintString - add sp, 0x2 + __PRINT_CSTR MemoryMap_OK ; FAT Driver setup call InitFATDriver + __PRINT_CSTR InitFATSYS_OK ; ; Find first cluster of bootable file ; call SearchFATDIR push dword eax - - lea ax, [FileFound_OK_cstr] - push ax - call PrintString - add sp, 0x2 - + __PRINT_CSTR FileFound_OK push dword eax call PrintDWORD ; void PrintDWORD(uint32_t dword) add sp, 0x4 - - lea ax, [NewLine_cstr] - push ax - call PrintString - add sp, 0x2 + __PRINT_CSTR NewLine - ERROR STEVIA_DEBUG_HALT hcf: hlt jmp short (hcf - $$) @@ -164,6 +140,11 @@ hcf: ; ; ############### +boot_drive_ptr: + dw 0x0000 +partition_offset_ptr: + dw 0x0000 + %include 'fat32/FAT32_SYS.inc' ; ############### @@ -180,8 +161,18 @@ hcf: ; ; ############################## +%ifnmacro __PRINT_CSTR + %macro __PRINT_CSTR 1 + lea ax, [%1_cstr] + push ax + call PrintString + add sp, 0x2 + %endmacro +%endif + ; Prints a C-Style string (null terminated) using BIOS vga teletype call ; void PrintString(char* buf) +ALIGN 4, db 0x90 PrintString: __CDECL16_ENTRY mov di, [bp + 4] ; first arg is char* @@ -214,6 +205,7 @@ PrintString: ; Prints a single character ; void PrintCharacter(char c); +ALIGN 4, db 0x90 PrintCharacter: __CDECL16_ENTRY .func: @@ -231,6 +223,7 @@ PrintCharacter: ; TODO: fix the prolog, epilog and stack usage to confirm with cdecl16 ; prints the hex representation of of val ; void PrintDWORD(uint32_t val); +ALIGN 4, db 0x90 PrintDWORD: __CDECL16_ENTRY .func: @@ -282,7 +275,7 @@ PrintDWORD: ; SYSTEM CONFIGURATION FUNCTIONS ; ; ############################## - +ALIGN 4, db 0x90 EnterUnrealMode: __CDECL16_ENTRY .func: @@ -342,28 +335,39 @@ EnterUnrealMode.unload_cs: ; ; ############# -%define StrCRLF_NUL 0Dh, 0Ah, 00h +%macro define_str 2 + ALIGN 4 + %1_str: + db %2 + %define str_length %strlen(%2) ; string + %1_str_len: + dd str_len +%endmacro -HelloPrompt_cstr: - db 'Stevia Stage2', StrCRLF_NUL -A20_Enabled_cstr: - db 'A20 Enabled OK', StrCRLF_NUL -MemoryMap_OK_cstr: - db 'Memory map OK', StrCRLF_NUL -UnrealMode_OK_cstr: - db 'Unreal mode OK', StrCRLF_NUL -FileFound_OK_cstr: - db 'Found SFN entry for bootable binary, first cluster -> ', 00h +; TODO: technically this is a cstr but it splices a return and newline on the end +; TODO: this probably should be seperated out and the printing functionality should +; TODO: place that newline and return +%macro define_cstr 2 +%define CRLF_NUL 0Dh, 0Ah, 00h + ALIGN 4 + %1_cstr: + db %2, StrCRLF_NUL +%endmacro + +define_cstr HelloPrompt, "Hello from Stevia Stage2!" +define_cstr A20_Enabled_OK, "A20 Enabled OK" +define_cstr MemoryMap_OK, "Memory map OK" +define_cstr UnrealMode_OK, "Unreal mode OK" +define_cstr FileFound_OK, "Found SFN entry for bootable binary, first cluster -> " +define_cstr InitFATSYS_OK, "FAT32 Driver Init..." +define_cstr NewLine, "" + + +define_str BootTarget, "BOOT BIN" + +ALIGN 4 IntToHex_table: db '0123456789ABCDEF' -NewLine_cstr: - db StrCRLF_NUL -BootTarget_str: - db "BOOT BIN" -boot_drive_ptr: - dw 0x0000 -partition_offset_ptr: - dw 0x0000 ; see docs/gdt.txt for a quick refresher on GDT ALIGN 4, db 0 @@ -450,6 +454,15 @@ gdt32_start: db 0x00 gdt32_end: +ALIGN 8 +version_magic: + db "Stevia Stage2 built with NASM - ", __NASM_VER__, 00h + +ALIGN 8 +datetime_magic: + db 'Assembled - ', __DATE__, ' ', __TIME__, 00h + + %assign bytes_remaining ((MAX_STAGE2_BYTES - 4) - ($ - $$)) %warning STAGE2 has bytes_remaining bytes remaining for code (MAX: MAX_STAGE2_BYTES)