Author: tkreuzer Date: Sat Jun 11 10:58:34 2011 New Revision: 52183
URL: http://svn.reactos.org/svn/reactos?rev=52183&view=rev Log: [BOOTSECTOR] Convert dosmbr to new syntax
Added: trunk/reactos/boot/freeldr/bootsect/dosmbr.S (with props) Modified: trunk/reactos/boot/freeldr/bootsect/CMakeLists.txt
Modified: trunk/reactos/boot/freeldr/bootsect/CMakeLists.txt URL: http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/bootsect/CMake... ============================================================================== --- trunk/reactos/boot/freeldr/bootsect/CMakeLists.txt [iso-8859-1] (original) +++ trunk/reactos/boot/freeldr/bootsect/CMakeLists.txt [iso-8859-1] Sat Jun 11 10:58:34 2011 @@ -1,7 +1,7 @@
if(ARCH MATCHES i386 OR ARCH MATCHES amd64)
-#CreateBootSectorTarget2(dosmbr ${CMAKE_CURRENT_SOURCE_DIR}/dosmbr.S ${CMAKE_CURRENT_BINARY_DIR}/dosmbr.bin 0) +CreateBootSectorTarget2(dosmbr ${CMAKE_CURRENT_SOURCE_DIR}/dosmbr.S ${CMAKE_CURRENT_BINARY_DIR}/dosmbr.bin 7c00) #CreateBootSectorTarget2(ext2 ${CMAKE_CURRENT_SOURCE_DIR}/ext2.S ${CMAKE_CURRENT_BINARY_DIR}/ext2.bin 0) CreateBootSectorTarget2(fat32 ${CMAKE_CURRENT_SOURCE_DIR}/fat32.S ${CMAKE_CURRENT_BINARY_DIR}/fat32.bin 7c00) #CreateBootSectorTarget2(fat ${CMAKE_CURRENT_SOURCE_DIR}/fat.S ${CMAKE_CURRENT_BINARY_DIR}/fat.bin 0) @@ -9,7 +9,6 @@ CreateBootSectorTarget2(isobtrt ${CMAKE_CURRENT_SOURCE_DIR}/isobtrt.S ${CMAKE_CURRENT_BINARY_DIR}/isobtrt.bin 7000)
if(NOT MSVC) -CreateBootSectorTarget(dosmbr ${CMAKE_CURRENT_SOURCE_DIR}/dosmbr.asm ${CMAKE_CURRENT_BINARY_DIR}/dosmbr.bin 0) CreateBootSectorTarget(ext2 ${CMAKE_CURRENT_SOURCE_DIR}/ext2.asm ${CMAKE_CURRENT_BINARY_DIR}/ext2.bin 0) CreateBootSectorTarget(fat ${CMAKE_CURRENT_SOURCE_DIR}/fat.asm ${CMAKE_CURRENT_BINARY_DIR}/fat.bin 0) endif()
Added: trunk/reactos/boot/freeldr/bootsect/dosmbr.S URL: http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/bootsect/dosmb... ============================================================================== --- trunk/reactos/boot/freeldr/bootsect/dosmbr.S (added) +++ trunk/reactos/boot/freeldr/bootsect/dosmbr.S [iso-8859-1] Sat Jun 11 10:58:34 2011 @@ -1,0 +1,187 @@ +/* + * COPYRIGHT: See COPYING in the top level directory + * PROJECT: ReactOS Bootsector for ISO file system + * PURPOSE: Normal DOS boot sector + * Ported to nasm from FreeDOS fdisk 1.2.0 by: + * PROGRAMMERS: Casper Hornstrup (chorns@users.sourceforge.net) + */ + +/* INCLUDES ******************************************************************/ + +#include <asm.inc> + +//----------------------------------------------------------------------- +// ENTRY (copied from freedos bootsector) +// +// IN: DL = boot drive +// OUT: DL = boot drive +// +//----------------------------------------------------------------------- + +.code16 +real_start: + cli + cld + xor ax, ax + mov ss, ax // initialize stack + mov ds, ax + mov bp, HEX(7c00) + lea sp, [bp-32] + sti + + /* Copy 512 bytes of MBR to 1fe0:7c00 */ + mov ax, HEX(1FE0) + mov es, ax + mov si, bp + mov di, bp + mov cx, 256 + rep movsw + + /* Jump into relocated code */ + ljmp16 HEX(1FE0), cont +cont: + + /* Setup segment registers */ + mov ds, ax + mov ss, ax + xor ax, ax + mov es, ax + + /* Search for active partition */ + lea di, [bp + HEX(1be)] // start of partition table +test_next_for_active: + test byte ptr ds:[di], HEX(80) + jne active_partition_found + add di, 16 // next table + cmp di, HEX(07c00) + HEX(1fe) // scanned beyond end of table ?? + jb test_next_for_active + +/*****************************************************************/ + call print + .asciz "no active partition found" + +WAIT_FOR_REBOOT: + jmp WAIT_FOR_REBOOT + + +/*****************************************************************/ +trouble_reading_drive: + call print + .asciz "read error while reading drive" + jmp WAIT_FOR_REBOOT + +/*****************************************************************/ + +invalid_partition_code: + call print + .asciz "partition signature != 55AA" + + jmp WAIT_FOR_REBOOT + +/*****************************************************************/ + +active_partition_found: +// call print +// .asciz "loading active partition" + + call read_boot_sector + + jc trouble_reading_drive + + cmp word ptr es:[HEX(7c00)+HEX(1fe)], HEX(0aa55) + jne invalid_partition_code + + ljmp16 0, HEX(7c00) // and jump to boot sector code + +/***************************** + * read_boot_sector + * + * IN: DI--> partition info + * OUT:CARRY + *****************************/ +read_boot_sector: + /* check for LBA support */ + mov bx, HEX(55aa) + mov ah, HEX(41) + int HEX(13) + + jc StandardBios // if (regs.b.x != 0xaa55 || (regs.flags & 0x01)) + cmp bx, HEX(0aa55) // goto StandardBios; + jne StandardBios + + /* if DAP cannot be used, don't use LBA + if ((regs.c.x & 1) == 0) + goto StandardBios; */ + test cl, 1 + jz StandardBios + + jmp short LBABios + + +_bios_LBA_address_packet: + .byte 16 + .byte 0 + .byte 4 // read four sectors - why not + .byte 0 + .word HEX(7c00) // fixed boot address for DOS sector + .word HEX(0000) + +_bios_LBA_low: + .word 0 +_bios_LBA_high: + .word 0 + .word 0,0 + + +LBABios: + // copy start address of partition to DAP + mov ax, [di + 8] + mov word ptr ds:[_bios_LBA_low], ax + mov ax,[di + 8 + 2] + mov word ptr ds:[_bios_LBA_high], ax + + mov ax, HEX(4200) // regs.a.x = LBA_READ; + mov si, offset _bios_LBA_address_packet // regs.si = FP_OFF(&dap); + + int HEX(13) + ret + +/***************************************************************** + * read disk, using standard BIOS + */ +StandardBios: + mov ax, HEX(0204) // regs.a.x = 0x0201; + mov bx, HEX(7c00) // regs.b.x = FP_OFF(buffer); + + /* regs.c.x = + ((chs.Cylinder & 0xff) << 8) + ((chs.Cylinder & 0x300) >> 2) + + ; chs.Sector; + that was easy ;-) */ + mov cx, word ptr ds:[di + 2] + mov dh, byte ptr ds:[di + 1] // regs.d.b.h = chs.Head; + // regs.es = FP_SEG(buffer); + int HEX(13) + ret + +/****** PRINT + * prints text after call to this function. + */ +print_1char: + xor bx, bx // video page 0 + mov ah, HEX(0E) // else print it + int HEX(10) // via TTY mode +print: + pop si // this is the first character +print1: + lodsb // get token + push si // stack up potential return address + cmp al, 0 // end of string? + jne print_1char // until done + ret // and jump to it + +.org 510 + .byte HEX(55), HEX(0aa) + +.endcode16 + +END
Propchange: trunk/reactos/boot/freeldr/bootsect/dosmbr.S ------------------------------------------------------------------------------ svn:eol-style = native
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tkreuzer＠svn.reactos.org