diff options
Diffstat (limited to 'boot2/stage2.asm')
| -rw-r--r-- | boot2/stage2.asm | 267 |
1 files changed, 0 insertions, 267 deletions
diff --git a/boot2/stage2.asm b/boot2/stage2.asm deleted file mode 100644 index 160d75c..0000000 --- a/boot2/stage2.asm +++ /dev/null @@ -1,267 +0,0 @@ -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -; -; THE FOOL-BOOT-LOADER -; -; * X sectors of our kernel loaded at KERNEL_OFFSET from floppy -; -; * memory map made available at MEMMAP_OFFSET -; (check at MEMMEP_SIZE_OFFSET for number of entries) -; -; * the VESA mode specified by VESA_MODE_SELECT will be set up -; (check at VESA_MODES, and VESA_MODE_INFO -; for additional information) -; -; * interrupts disabled -; -; * 32-bit protected mode set up. -; -; * esp set under MBR -; -; * A20 gate opened -; -; * and finally we will jump into the C world to kernel_main() ! -; -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; - - -;we want 16-bit instructions, before we switch to 32-bit protected mode. -[bits 16] - -;define origin of boot record in memory: 0x7c00 was bootloader0 -;this is where the BIOS per definition will put the first -;512 bytes of data from the boot device -;wer are one sector after that. -[org 0x7e00] - -;;define some constants -;;where we will load our kernel into memory and some -;;other memory locations -; -MEMMAP_SIZE_OFFSET equ 0xa000 -MEMMAP_OFFSET equ 0xa001 - -VESA_MODES equ 0xb000 ; do NOT overwrite yourself! be careful! -VESA_MODE_INFO equ 0xc000 - -VESA_MODE_SELECT equ 0x4114 -CHUNKS_TO_LOAD equ 0x20 ;number of 0x8000 * 512 byte chunks to load into ram -; - -jmp boot_16 ;start boot process - -;;SOME Global Data, mainly info/error strings -FILL: - times 32 db 0x66 - -BOOT_DRIVE: - db 0xff - -LOADER_TARGET: - dd 0x100000 ;here we will put our image - -KERNEL_CHUNK: - dw 0x1 -STR_VERSION: - db "Fool Loader Stage 2 v0.5",0 - -STR_LOAD: - db "Loading Kernel...",0 -STR_BOOT: - db "Boot Drive: ",0 -MEMMAP_INFO: - db "Getting Memory Map from BIOS.",0 -STR_PM: - db "PROTECTED MODE",0 - -; kernel config -%include "config.inc" - -; -;;lets put our temporary GDT (Global Descriptor Table) here -;;kernel should move this away -%include "GDT.asm" -; -;;include 16-bit real mode routines (print_string, disk_load, vesa_setup,check_a20) -%include "disk_load_16.asm" -;%include "boot/check_a20_16.asm" -%include "print_string_16.asm" -%include "vesa_setup_16.asm" -; -;;include our routines for switching to 32-bit protected mode -%include "pm.asm" - -;include some pm mode helpers -%include "common_pm.asm" - -; -; -; -;;get memory map routine -%include "memmap.asm" -; -;;;;;;;;; BOOT 16-bit real ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -; -;;lets start -[bits 16] - -idt_real: - dw 0x3ff ; 256 entries, 4b each = 1K - dd 0 ; Real Mode IVT @ 0x0000 - -boot_16: - - mov [BOOT_DRIVE],dl - - - ; hide text-mode cursor - mov ah,0x01 - mov cx,0x2607 - int 0x10 - - - ;pr info - mov bx, STR_VERSION - call print_string - call print_nextline - - ;show bootdrive - mov bx, STR_BOOT - call print_string - mov al,dl - call print_hex_byte - call print_nextline - - - ; memmap message - mov bx,MEMMAP_INFO - call print_string - call print_nextline - - ;get memory map from bios before we enter 32 bit protected mode - mov ax,0 ; set target address in es:di (0:offset) - mov es,ax - mov di,MEMMAP_OFFSET - call BiosGetMemoryMap ; this will also put the number of entries - ; of the memory map at MEMMAP_SIZE_OFFSET - - ; Load the KERNEL Image - mov bx, STR_LOAD - call print_string - call print_nextline - -kernel_load: - - call disk_load_16 - - - - ; init vesa on last iteration! - mov ax,[KERNEL_CHUNK] - cmp ax,(CHUNKS_TO_LOAD-1) - jne skip_vesa_init - - %ifndef FOOLOS_CONSOLE - call VesaSetup - %endif - - skip_vesa_init: - - call switch_to_pm -; -;;;;;;;;; BOOT 32-bit protected mode;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -[bits 32] -boot_32_pm: - - ;Fast A20 Gate: - ;http://wiki.osdev.org/A20_Line - in al, 0x92 - or al, 2 - out 0x92, al - - ; tell the world we are protected - ;mov ebx,STR_PM - ;mov ecx,2*23*80 - ;call print_string_pm - - ;increment chunk number - mov ax,[KERNEL_CHUNK] - add ax,1 - mov [KERNEL_CHUNK],ax - - ;check if all chunkgs loaded (hardcoded to 0x6 for a start) - ;each chunk is 0x8000 * 15 bytes - cmp ax,CHUNKS_TO_LOAD - je finish_load - - ; show KERNEL CHUNK value -; push edx ; persist edx for some reason!? -; mov edx,0 -; mov dx,[KERNEL_CHUNK] -; mov ecx,2*24*80 -; call print_hex_pm -; pop edx - - - ; here we actually do copy the chunk into ext mem! - mov eax,[LOADER_TARGET] - mov ebx,0x18000 - - copy_next_byte: - - mov ecx,[ebx] - mov [eax],ecx - - inc eax - inc ebx - cmp ebx, 0x90000 - - jne copy_next_byte - mov [LOADER_TARGET],eax ;persist next target address - - - ; and now go back to real! (first 16bit protected!) - jmp CODE16_SEG:reinit_16 - - finish_load: - ; - - ; call kernel! - mov eax,0 ;tell the kernel - ; we are the booting processor - jmp 0x100000 ;jump into our Kernel! - - -[bits 16] -reinit_16: ;16 bit protected mode - - mov eax,DATA16_SEG - mov ds,eax - mov es,eax - mov fs,eax - mov gs,eax - mov ss,eax - - - mov eax,cr0 - and eax,!0x1 ; Disable protected mode - mov cr0, eax - - jmp 0:realmode - - -realmode: - - mov sp,0x07000 - mov bp,sp - - mov ax,0 - mov ds,ax - mov es,ax - mov fs,ax - mov gs,ax - mov ss,ax - - lidt [idt_real] - - sti - jmp kernel_load |