X-Git-Url: http://git.joshuawise.com/netwatch.git/blobdiff_plain/f23390bfddcc23940178f04c6745d9c7fcf9d1ea..4bea7daf0e70a1540b8533c8253c197bb282416e:/aseg/aseg.asm diff --git a/aseg/aseg.asm b/aseg/aseg.asm index 51a2811..ee83272 100644 --- a/aseg/aseg.asm +++ b/aseg/aseg.asm @@ -1,48 +1,33 @@ - org 0x0 + org 0xA8000 [bits 16] entry: -; mov al, 0x01 ; Say where we are. -; out 0x80, al mov ax, 0xA800 mov ds, ax ; Take us out of flat unreal mode, and mov es, ax ; put us in true real mode. mov fs, ax mov gs, ax mov ss, ax - jmp 0xA800:entry2 ; Long jump to a correct cs. + jmp 0xA800:(entry2-0xA8000) ; Long jump to a correct cs. entry2: -; mov al, 0x02 -; out 0x80, al - lgdt [gdtr] ; Set up a new GDT. + lgdt [(gdtr-0xA8000)] ; Set up a new GDT. mov eax, 0x1 mov cr0, eax ; ... and enter pmode! - mov al, 0x03 ; Say we got here. - out 0x80, al - jmp long 0x10:(continue+0xA8000) ; Now longjmp into the new code. + jmp long 0x10:continue ; Now longjmp into the new code. [bits 32] continue: -; mov al, 0x04 ; Now we're in protected mode. -; out 0x80, al - mov ax, 0x08 ; Set up segment selectors. mov ds, ax mov es, ax mov fs, ax mov gs, ax mov ss, ax - mov esp, 0x1fffffff + mov esp, [dataptr] -; mov al, 0x05 +; mov al, [cstat] +; add al, 1 ; out 0x80, al - - mov al, [(cstat + 0xA8000)] - add al, 1 - out 0x80, al - mov [(cstat + 0xA8000)], al +; mov [cstat], al - mov eax, 0x11223344 - mov dword [(status + 0xA8000)], eax - mov dx, 0xCF8 ; save off the old config value in dword eax, dx mov [esp-4], eax @@ -73,26 +58,33 @@ continue: shl eax, 1 add eax, 0xB8000 ; yay mov byte [eax+0], '1' - mov byte [eax+1], 0xA0 + mov byte [eax+1], 0x1F mov byte [eax+2], '5' - mov byte [eax+3], 0xA0 + mov byte [eax+3], 0x1F mov byte [eax+4], '-' - mov byte [eax+5], 0xA0 + mov byte [eax+5], 0x1F mov byte [eax+6], '4' - mov byte [eax+7], 0xA0 + mov byte [eax+7], 0x1F mov byte [eax+8], '1' - mov byte [eax+9], 0xA0 + mov byte [eax+9], 0x1F mov byte [eax+10], '2' - mov byte [eax+11], 0xA0 + mov byte [eax+11], 0x1F - mov dx, 0x3D4 + mov dx, 0x3D4 ; restore the old stuff mov al, [esp-6] out dx, al - + + mov al, 0 + mov edi, [dataptr+4] ; clear BSS + mov ecx, [dataptr+8] + rep stosb mov dx, 0xCFC ; restore smramc mov al, [esp-5] out dx, al + + mov eax, [dataptr+12] + call eax mov dx, 0xCF8 ; restore the old config value mov eax, [esp-4] @@ -115,7 +107,7 @@ continue: align 0x4 gdtr: db 0x27, 0x00 - dd (gdt + 0xA8000) + dd gdt align 0x4 gdt: db 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 @@ -123,8 +115,12 @@ gdt: db 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x9B, 0xCF, 0x00 ; code segment db 0xFF, 0xFF, 0x00, 0x80, 0x0A, 0x9B, 0xCF, 0x00 ; code segment for trampoline -TIMES 512-($-$$) DB 0 -status: - dd 0xAA55AA55 cstat: db 0x00 + +TIMES 512-($-$$) DB 0 +dataptr: + ; 4 bytes of stack top + ; 4 bytes of BSS start + ; 4 bytes of BSS length + ; 4 bytes of C entry point \ No newline at end of file