X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=blobdiff_plain;f=palacios%2Fsrc%2Fgeekos%2Ffd_boot.asm;h=2fbfd35d9f65230ca31e33dd60da1e00c9e2cd87;hp=46f920fcdff4decb4b642a5cea2dc94931351bdf;hb=57e3d7d1e671a261befef967b4a441e5d7dc2303;hpb=20885b915c6caf47c8bd78d7b5b492fef388ac2d diff --git a/palacios/src/geekos/fd_boot.asm b/palacios/src/geekos/fd_boot.asm index 46f920f..2fbfd35 100644 --- a/palacios/src/geekos/fd_boot.asm +++ b/palacios/src/geekos/fd_boot.asm @@ -1,7 +1,7 @@ ; Boot sector for GeekOS ; Copyright (c) 2001,2004 David H. Hovemeyer ; Copyright (c) 2003, Jeffrey K. Hollingsworth -; $Revision: 1.5 $ +; $Revision: 1.6 $ ; This is free software. You are permitted to use, ; redistribute, and modify it as specified in the file "COPYING". @@ -89,6 +89,8 @@ load_setup: cmp word [sec_count], bx jl .again + + load_kernel: ; Load the kernel image from sectors KERN_START_SEC..n of the ; floppy into memory at KERNSEG. Note that there are 128 sectors @@ -102,54 +104,8 @@ load_kernel: mov word [sec_count], ax add ax, word [kernelSize] mov word [max_sector], ax -.again: - mov ax, [sec_count] ; logical sector on the floppy -; mov dx, ax -; call PrintHex -; call PrintNL - push ax ; 1st param to ReadSector (log sec num) - sub ax, [kernelStart] ; convert to 0-indexed - mov cx, ax ; save in cx - shr ax, 7 ; divide by 128 - shl ax, 12 ; ...and multiply by 0x1000 - add ax, KERNSEG ; ...to get base relative to KERNSEG -; mov dx, ax -; call PrintHex -; call PrintNL - push ax ; 2nd param to ReadSector (seg base) - and cx, 0x7f ; mod sector by 128 - shl cx, 9 ; ...and multiply by 512 - push cx ; to get offset in segment (3rd parm) -; mov dx, cx -; call PrintHex -; call PrintNL - - - ; read the sector from the floppy - call ReadSector - add sp, 6 ; clear 3 word params - - - ; on to next sector - inc word [sec_count] - - ; have we loaded all of the sectors? - mov bx, word [max_sector] - cmp word [sec_count], bx - jl .again - -load_vm: - ; Load the guest image starting at 1MB - ; floppy into memory at KERNSEG. Note that there are 128 sectors - ; per 64K segment. So, when figuring out which segment to - ; load the sector into, we shift right by 7 bits (which is - ; equivalent to dividing by 128). - ; Figure out start sector and max sector - mov ax, word [vmStart] - mov word [sec_count], ax - add ax, word [vmSize] - mov word [max_sector], ax + .again2: mov ax, [sec_count] ; logical sector on the floppy @@ -456,13 +412,7 @@ kernelStart: kernelSize: dw NUM_KERN_SECTORS - ;; part of pfat boot record -vmStart: - dw 1+NUM_SETUP_SECTORS+NUM_KERN_SECTORS - ;; part of pfat boot record -vmSize: - dw NUM_VM_KERNEL_SECTORS ; Finish by writing the BIOS signature to mark this as