diff options
Diffstat (limited to 'stand/i386/zfsboot/zfsldr.S')
| -rw-r--r-- | stand/i386/zfsboot/zfsldr.S | 281 |
1 files changed, 0 insertions, 281 deletions
diff --git a/stand/i386/zfsboot/zfsldr.S b/stand/i386/zfsboot/zfsldr.S deleted file mode 100644 index cd8289f952fd..000000000000 --- a/stand/i386/zfsboot/zfsldr.S +++ /dev/null @@ -1,281 +0,0 @@ -/* - * Copyright (c) 1998 Robert Nordier - * All rights reserved. - * - * Redistribution and use in source and binary forms are freely - * permitted provided that the above copyright notice and this - * paragraph and the following disclaimer are duplicated in all - * such forms. - * - * This software is provided "AS IS" and without any express or - * implied warranties, including, without limitation, the implied - * warranties of merchantability and fitness for a particular - * purpose. - */ - -/* Memory Locations */ - .set MEM_ARG,0x900 # Arguments - .set MEM_ORG,0x7c00 # Origin - .set MEM_BUF,0x8000 # Load area - .set MEM_BTX,0x9000 # BTX start - .set MEM_JMP,0x9010 # BTX entry point - .set MEM_USR,0xa000 # Client start - .set BDA_BOOT,0x472 # Boot howto flag - -/* Partition Constants */ - .set PRT_OFF,0x1be # Partition offset - .set PRT_NUM,0x4 # Partitions - .set PRT_BSD,0xa5 # Partition type - -/* Misc. Constants */ - .set SIZ_PAG,0x1000 # Page size - .set SIZ_SEC,0x200 # Sector size - .set COPY_BLKS,0x8 # Number of blocks - # to copy for boot2 (<= 15) - .set COPY_BLK_SZ,0x8000 # Copy in 32k blocks; must be - # a multiple of 16 bytes - .set NSECT,(COPY_BLK_SZ / SIZ_SEC * COPY_BLKS) - .globl start - .code16 - -/* - * Load the rest of zfsboot2 and BTX up, copy the parts to the right locations, - * and start it all up. - */ - -/* - * Setup the segment registers to flat addressing (segment 0) and setup the - * stack to end just below the start of our code. - */ -start: cld # String ops inc - xor %cx,%cx # Zero - mov %cx,%es # Address - mov %cx,%ds # data - mov %cx,%ss # Set up - mov $start,%sp # stack -/* - * Load the MBR and look for the first FreeBSD slice. We use the fake - * partition entry below that points to the MBR when we call read. - * The first pass looks for the first active FreeBSD slice. The - * second pass looks for the first non-active FreeBSD slice if the - * first one fails. - */ - call check_edd # Make sure EDD works - mov $part4,%si # Dummy partition - xor %eax,%eax # Read MBR - movl $MEM_BUF,%ebx # from first - call read # sector - mov $0x1,%cx # Two passes -main.1: mov $MEM_BUF+PRT_OFF,%si # Partition table - movb $0x1,%dh # Partition -main.2: cmpb $PRT_BSD,0x4(%si) # Our partition type? - jne main.3 # No - jcxz main.5 # If second pass - testb $0x80,(%si) # Active? - jnz main.5 # Yes -main.3: add $0x10,%si # Next entry - incb %dh # Partition - cmpb $0x1+PRT_NUM,%dh # In table? - jb main.2 # Yes - dec %cx # Do two - jcxz main.1 # passes -/* - * If we get here, we didn't find any FreeBSD slices at all, so print an - * error message and die. - */ - mov $msg_part,%si # Message - jmp error # Error - -/* - * Ok, we have a slice and drive in %dx now, so use that to locate and - * load boot2. %si references the start of the slice we are looking - * for, so go ahead and load up the COPY_BLKS*COPY_BLK_SZ/SIZ_SEC sectors - * starting at sector 1024 (i.e. after the two vdev labels). We don't - * have do anything fancy here to allow for an extra copy of boot1 and - * a partition table (compare to this section of the UFS bootstrap) so we - * just load it all at 0x9000. The first part of boot2 is BTX, which wants - * to run at 0x9000. The boot2.bin binary starts right after the end of BTX, - * so we have to figure out where the start of it is and then move the - * binary to 0xc000. Normally, BTX clients start at MEM_USR, or 0xa000, - * but when we use btxld to create zfsboot2, we use an entry point of - * 0x2000. That entry point is relative to MEM_USR; thus boot2.bin - * starts at 0xc000. - * - * The load area and the target area for the client overlap so we have - * to use a decrementing string move. We also play segment register - * games with the destination address for the move so that the client - * can be larger than 16k (which would overflow the zero segment since - * the client starts at 0xc000). - */ -main.5: mov %dx,MEM_ARG # Save args - mov $NSECT,%cx # Sector count - movl $1024,%eax # Offset to boot2 - mov $MEM_BTX,%ebx # Destination buffer -main.6: pushal # Save params - call read # Read disk - popal # Restore - incl %eax # Advance to - add $SIZ_SEC,%ebx # next sector - loop main.6 # If not last, read another - - mov $MEM_BTX,%bx # BTX - mov 0xa(%bx),%si # Get BTX length and set - add %bx,%si # %si to start of boot2 - dec %si # Set %ds:%si to point at the - mov %si,%ax # last byte we want to copy - shr $4,%ax # from boot2, with %si made as - add $(COPY_BLKS*COPY_BLK_SZ/16),%ax # small as possible. - and $0xf,%si # - mov %ax,%ds # - mov $(MEM_USR+2*SIZ_PAG)/16,%ax # Set %es:(-1) to point at - add $(COPY_BLKS*COPY_BLK_SZ/16),%ax # the last byte we - mov %ax,%es # want to copy boot2 into. - mov $COPY_BLKS,%bx # Copy COPY_BLKS 32k blocks -copyloop: - add $COPY_BLK_SZ,%si # Adjust %ds:%si to point at - mov %ds,%ax # the end of the next 32k to - sub $COPY_BLK_SZ/16,%ax # copy from boot2 - mov %ax,%ds - mov $COPY_BLK_SZ-1,%di # Adjust %es:%di to point at - mov %es,%ax # the end of the next 32k into - sub $COPY_BLK_SZ/16,%ax # which we want boot2 copied - mov %ax,%es - mov $COPY_BLK_SZ,%cx # Copy 32k - std - rep movsb - dec %bx - jnz copyloop - mov %cx,%ds # Reset %ds and %es - mov %cx,%es - cld # Back to increment - -/* - * Enable A20 so we can access memory above 1 meg. - * Use the zero-valued %cx as a timeout for embedded hardware which do not - * have a keyboard controller. - */ -seta20: cli # Disable interrupts -seta20.1: dec %cx # Timeout? - jz seta20.3 # Yes - inb $0x64,%al # Get status - testb $0x2,%al # Busy? - jnz seta20.1 # Yes - movb $0xd1,%al # Command: Write - outb %al,$0x64 # output port -seta20.2: inb $0x64,%al # Get status - testb $0x2,%al # Busy? - jnz seta20.2 # Yes - movb $0xdf,%al # Enable - outb %al,$0x60 # A20 -seta20.3: sti # Enable interrupts - - jmp start+MEM_JMP-MEM_ORG # Start BTX - - -/* - * Read a sector from the disk. Sets up an EDD packet on the stack - * and passes it to read. We assume that the destination address is - * always segment-aligned. - * - * %eax - int - LBA to read in relative to partition start - * %ebx - ptr - destination address - * %dl - byte - drive to read from - * %si - ptr - MBR partition entry - */ -read: xor %ecx,%ecx # Get - addl 0x8(%si),%eax # LBA - adc $0,%ecx - pushl %ecx # Starting absolute block - pushl %eax # block number - shr $4,%ebx # Convert to segment - push %bx # Address of - push $0 # transfer buffer - push $0x1 # Read 1 sector - push $0x10 # Size of packet - mov %sp,%si # Packet pointer - mov $0x42,%ah # BIOS: Extended - int $0x13 # read - jc read.1 # If error, fail - lea 0x10(%si),%sp # Clear stack - ret # If success, return -read.1: mov %ah,%al # Format - mov $read_err,%di # error - call hex8 # code - mov $msg_read,%si # Set the error message and - # fall through to the error - # routine -/* - * Print out the error message pointed to by %ds:(%si) followed - * by a prompt, wait for a keypress, and then reboot the machine. - */ -error: callw putstr # Display message - mov $prompt,%si # Display - callw putstr # prompt - xorb %ah,%ah # BIOS: Get - int $0x16 # keypress - movw $0x1234, BDA_BOOT # Do a warm boot - ljmp $0xffff,$0x0 # reboot the machine -/* - * Display a null-terminated string using the BIOS output. - */ -putstr.0: mov $0x7,%bx # Page:attribute - movb $0xe,%ah # BIOS: Display - int $0x10 # character -putstr: lodsb # Get char - testb %al,%al # End of string? - jne putstr.0 # No - ret # To caller -/* - * Check to see if the disk supports EDD. zfsboot requires EDD and does not - * support older C/H/S disk I/O. - */ -check_edd: cmpb $0x80,%dl # Hard drive? - jb check_edd.1 # No, fail to boot - mov $0x55aa,%bx # Magic - push %dx # Save - movb $0x41,%ah # BIOS: Check - int $0x13 # extensions present - pop %dx # Restore - jc check_edd.1 # If error, fail - cmp $0xaa55,%bx # Magic? - jne check_edd.1 # No, so fail - testb $0x1,%cl # Packet interface? - jz check_edd.1 # No, so fail - ret # EDD ok, keep booting -check_edd.1: mov $msg_chs,%si # Warn that CHS is - jmp error # unsupported and fail -/* - * AL to hex, saving the result to [EDI]. - */ -hex8: push %ax # Save - shrb $0x4,%al # Do upper - call hex8.1 # 4 - pop %ax # Restore -hex8.1: andb $0xf,%al # Get lower 4 - cmpb $0xa,%al # Convert - sbbb $0x69,%al # to hex - das # digit - orb $0x20,%al # To lower case - stosb # Save char - ret # (Recursive) - -/* Messages */ - -msg_chs: .asciz "CHS not supported" -msg_read: .ascii "Read error: " -read_err: .asciz "XX" -msg_part: .asciz "Boot error" - -prompt: .asciz "\r\n" - - .org PRT_OFF,0x90 - -/* Partition table */ - - .fill 0x30,0x1,0x0 -part4: .byte 0x80, 0x00, 0x01, 0x00 - .byte 0xa5, 0xfe, 0xff, 0xff - .byte 0x00, 0x00, 0x00, 0x00 - .byte 0x50, 0xc3, 0x00, 0x00 # 50000 sectors long, bleh - - .word 0xaa55 # Magic number |