diff options
Diffstat (limited to 'boot/mbr.asm')
| -rw-r--r-- | boot/mbr.asm | 41 |
1 files changed, 18 insertions, 23 deletions
diff --git a/boot/mbr.asm b/boot/mbr.asm index 83edefc..bb1fc2b 100644 --- a/boot/mbr.asm +++ b/boot/mbr.asm @@ -1,39 +1,34 @@ -;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; -; FoolOS Boot Loader +; THE FOOL-BOOT-LOADER ; -; Copyright 2014 M.Idziorek <m.i@gmx.at> -; -; we have just been loaded by the BIOS and are in 16-bits real mode! -; -; THIS IS THE CENTRAL FILE OF THE BOOTLOADER, -; -; after we are through, -; the following work has been accomplished (chronologically): +; So we have just been loaded by the BIOS and are in 16-bits real mode! +; Now the following work will bee accomplished (chronologically): ; -; * BOOT_DRIVE is set +; * BOOT_DRIVE set ; -; * 50 sectors of our kernel are loaded at KERNEL_OFFSET from floppy +; * 50 sectors of our kernel loaded at KERNEL_OFFSET from floppy ; -; * memoru map is available at MEMMAP_OFFSET -; (look at MEMMEP_SIZE_OFFSET for number of entries) +; * memory map made available at MEMMAP_OFFSET +; (check at MEMMEP_SIZE_OFFSET for number of entries) ; -; * the vesa mode specified by VESA_MODE_SELECT is set up -; (at VESA_MODES, and VESA_MODE_INFO additional info structs are available) +; * 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 was set up. +; * 32-bit protected mode set up. ; ; * esp set to 0x90000 (Todo: take care of it!?) ; -; * A20 gate is open +; * A20 gate opened (Todo: really necessary?) ; -; * PICs are configured +; * PICs configured ; -; * we are inside the C kernel! +; * 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] @@ -104,9 +99,9 @@ boot_16: ;remember BOOT_DRIVE (as was set by BIOS) mov [BOOT_DRIVE],dl - ;Load the KERNEL (50 sectors starting at sector 2) + ;Load the KERNEL (52 sectors starting at sector 2) mov bx,KERNEL_OFFSET - mov dh, 50 ;50 sectors! + mov dh, 52 mov dl, [BOOT_DRIVE] call disk_load |