diff options
Diffstat (limited to 'gpxe/src/arch/i386/prefix/bootpart.S')
| -rw-r--r-- | gpxe/src/arch/i386/prefix/bootpart.S | 218 |
1 files changed, 0 insertions, 218 deletions
diff --git a/gpxe/src/arch/i386/prefix/bootpart.S b/gpxe/src/arch/i386/prefix/bootpart.S deleted file mode 100644 index 968da1a3..00000000 --- a/gpxe/src/arch/i386/prefix/bootpart.S +++ /dev/null @@ -1,218 +0,0 @@ -FILE_LICENCE ( GPL2_OR_LATER ) - -#define BOOT_SEG 0x07c0 -#define EXEC_SEG 0x0100 -#define STACK_SEG 0x0200 -#define STACK_SIZE 0x2000 - - .text - .arch i386 - .section ".prefix", "awx", @progbits - .code16 - -/* - * Find active partition - * - * Parameters: - * %dl : BIOS drive number - * %bp : Active partition handler routine - */ -find_active_partition: - /* Set up stack at STACK_SEG:STACK_SIZE */ - movw $STACK_SEG, %ax - movw %ax, %ss - movw $STACK_SIZE, %sp - - /* Relocate self to EXEC_SEG */ - pushw $BOOT_SEG - popw %ds - pushw $EXEC_SEG - popw %es - xorw %si, %si - xorw %di, %di - movw $0x200, %cx - rep movsb - ljmp $EXEC_SEG, $1f -1: pushw %ds - popw %es - pushw %cs - popw %ds - - /* Check for LBA extensions */ - movb $0x41, %ah - movw $0x55aa, %bx - stc - int $0x13 - jc 1f - cmpw $0xaa55, %bx - jne 1f - movw $read_lba, read_sectors -1: - /* Read and process root partition table */ - xorb %dh, %dh - movw $0x0001, %cx - xorl %esi, %esi - xorl %edi, %edi - call process_table - - /* Print failure message */ - movw $10f, %si - jmp boot_error -10: .asciz "Could not locate active partition\r\n" - -/* - * Print failure message and boot next device - * - * Parameters: - * %si : Failure string - */ -boot_error: - cld - movw $0x0007, %bx - movb $0x0e, %ah -1: lodsb - testb %al, %al - je 99f - int $0x10 - jmp 1b -99: /* Boot next device */ - int $0x18 - -/* - * Process partition table - * - * Parameters: - * %dl : BIOS drive number - * %dh : Head - * %cl : Sector (bits 0-5), high two bits of cylinder (bits 6-7) - * %ch : Low eight bits of cylinder - * %esi:%edi : LBA address - * %bp : Active partition handler routine - * - * Returns: - * CF set on error - */ -process_table: - pushal - call read_boot_sector - jc 99f - movw $446, %bx -1: call process_partition - addw $16, %bx - cmpw $510, %bx - jne 1b -99: popal - ret - -/* - * Process partition - * - * Parameters: - * %dl : BIOS drive number - * %dh : Head - * %cl : Sector (bits 0-5), high two bits of cylinder (bits 6-7) - * %ch : Low eight bits of cylinder - * %esi:%edi : LBA address - * %bx : Offset within partition table - * %bp : Active partition handler routine - */ -process_partition: - pushal - /* Load C/H/S values from partition entry */ - movb %es:1(%bx), %dh - movw %es:2(%bx), %cx - /* Update LBA address from partition entry */ - addl %es:8(%bx), %edi - adcl $0, %esi - /* Check active flag */ - testb $0x80, %es:(%bx) - jz 1f - call read_boot_sector - jc 99f - jmp *%bp -1: /* Check for extended partition */ - movb %es:4(%bx), %al - cmpb $0x05, %al - je 2f - cmpb $0x0f, %al - je 2f - cmpb $0x85, %al - jne 99f -2: call process_table -99: popal - /* Reload original partition table */ - call read_boot_sector - ret - -/* - * Read single sector to %es:0000 and verify 0x55aa signature - * - * Parameters: - * %dl : BIOS drive number - * %dh : Head - * %cl : Sector (bits 0-5), high two bits of cylinder (bits 6-7) - * %ch : Low eight bits of cylinder - * %esi:%edi : LBA address - * - * Returns: - * CF set on error - */ -read_boot_sector: - pushw %ax - movw $1, %ax - call *read_sectors - jc 99f - cmpw $0xaa55, %es:(510) - je 99f - stc -99: popw %ax - ret - -/* - * Read sectors to %es:0000 - * - * Parameters: - * %dl : BIOS drive number - * %dh : Head - * %cl : Sector (bits 0-5), high two bits of cylinder (bits 6-7) - * %ch : Low eight bits of cylinder - * %esi:%edi : LBA address - * %ax : Number of sectors (max 127) - * - * Returns: - * CF set on error - */ -read_sectors: .word read_chs - -read_chs: - /* Read sectors using C/H/S address */ - pushal - xorw %bx, %bx - movb $0x02, %ah - stc - int $0x13 - sti - popal - ret - -read_lba: - /* Read sectors using LBA address */ - pushal - movw %ax, (lba_desc + 2) - pushw %es - popw (lba_desc + 6) - movl %edi, (lba_desc + 8) - movl %esi, (lba_desc + 12) - movw $lba_desc, %si - movb $0x42, %ah - int $0x13 - popal - ret - -lba_desc: - .byte 0x10 - .byte 0 - .word 1 - .word 0x0000 - .word 0x0000 - .long 0, 0 |