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Diffstat (limited to 'arch/i386/boot/edd.S')
| -rw-r--r-- | arch/i386/boot/edd.S | 231 |
1 files changed, 0 insertions, 231 deletions
diff --git a/arch/i386/boot/edd.S b/arch/i386/boot/edd.S deleted file mode 100644 index 34321368011a..000000000000 --- a/arch/i386/boot/edd.S +++ /dev/null @@ -1,231 +0,0 @@ -/* - * BIOS Enhanced Disk Drive support - * Copyright (C) 2002, 2003, 2004 Dell, Inc. - * by Matt Domsch <Matt_Domsch@dell.com> October 2002 - * conformant to T13 Committee www.t13.org - * projects 1572D, 1484D, 1386D, 1226DT - * disk signature read by Matt Domsch <Matt_Domsch@dell.com> - * and Andrew Wilks <Andrew_Wilks@dell.com> September 2003, June 2004 - * legacy CHS retrieval by Patrick J. LoPresti <patl@users.sourceforge.net> - * March 2004 - * Command line option parsing, Matt Domsch, November 2004 - */ - -#include <linux/edd.h> -#include <asm/setup.h> - -#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE) - -# It is assumed that %ds == INITSEG here - - movb $0, (EDD_MBR_SIG_NR_BUF) - movb $0, (EDDNR) - -# Check the command line for options: -# edd=of disables EDD completely (edd=off) -# edd=sk skips the MBR test (edd=skipmbr) -# edd=on re-enables EDD (edd=on) - - pushl %esi - movw $edd_mbr_sig_start, %di # Default to edd=on - - movl %cs:(cmd_line_ptr), %esi - andl %esi, %esi - jz old_cl # Old boot protocol? - -# Convert to a real-mode pointer in fs:si - movl %esi, %eax - shrl $4, %eax - movw %ax, %fs - andw $0xf, %si - jmp have_cl_pointer - -# Old-style boot protocol? -old_cl: - push %ds # aka INITSEG - pop %fs - - cmpw $0xa33f, (0x20) - jne done_cl # No command line at all? - movw (0x22), %si # Pointer relative to INITSEG - -# fs:si has the pointer to the command line now -have_cl_pointer: - -# Loop through kernel command line one byte at a time. Just in -# case the loader is buggy and failed to null-terminate the command line -# terminate if we get close enough to the end of the segment that we -# cannot fit "edd=XX"... -cl_atspace: - cmpw $-5, %si # Watch for segment wraparound - jae done_cl - movl %fs:(%si), %eax - andb %al, %al # End of line? - jz done_cl - cmpl $EDD_CL_EQUALS, %eax - jz found_edd_equals - cmpb $0x20, %al # <= space consider whitespace - ja cl_skipword - incw %si - jmp cl_atspace - -cl_skipword: - cmpw $-5, %si # Watch for segment wraparound - jae done_cl - movb %fs:(%si), %al # End of string? - andb %al, %al - jz done_cl - cmpb $0x20, %al - jbe cl_atspace - incw %si - jmp cl_skipword - -found_edd_equals: -# only looking at first two characters after equals -# late overrides early on the command line, so keep going after finding something - movw %fs:4(%si), %ax - cmpw $EDD_CL_OFF, %ax # edd=of - je do_edd_off - cmpw $EDD_CL_SKIP, %ax # edd=sk - je do_edd_skipmbr - cmpw $EDD_CL_ON, %ax # edd=on - je do_edd_on - jmp cl_skipword -do_edd_skipmbr: - movw $edd_start, %di - jmp cl_skipword -do_edd_off: - movw $edd_done, %di - jmp cl_skipword -do_edd_on: - movw $edd_mbr_sig_start, %di - jmp cl_skipword - -done_cl: - popl %esi - jmpw *%di - -# Read the first sector of each BIOS disk device and store the 4-byte signature -edd_mbr_sig_start: - movb $0x80, %dl # from device 80 - movw $EDD_MBR_SIG_BUF, %bx # store buffer ptr in bx -edd_mbr_sig_read: - movl $0xFFFFFFFF, %eax - movl %eax, (%bx) # assume failure - pushw %bx - movb $READ_SECTORS, %ah - movb $1, %al # read 1 sector - movb $0, %dh # at head 0 - movw $1, %cx # cylinder 0, sector 0 - pushw %es - pushw %ds - popw %es - movw $EDDBUF, %bx # disk's data goes into EDDBUF - pushw %dx # work around buggy BIOSes - stc # work around buggy BIOSes - int $0x13 - sti # work around buggy BIOSes - popw %dx - popw %es - popw %bx - jc edd_mbr_sig_done # on failure, we're done. - cmpb $0, %ah # some BIOSes do not set CF - jne edd_mbr_sig_done # on failure, we're done. - movl (EDDBUF+EDD_MBR_SIG_OFFSET), %eax # read sig out of the MBR - movl %eax, (%bx) # store success - incb (EDD_MBR_SIG_NR_BUF) # note that we stored something - incb %dl # increment to next device - addw $4, %bx # increment sig buffer ptr - cmpb $EDD_MBR_SIG_MAX, (EDD_MBR_SIG_NR_BUF) # Out of space? - jb edd_mbr_sig_read # keep looping -edd_mbr_sig_done: - -# Do the BIOS Enhanced Disk Drive calls -# This consists of two calls: -# int 13h ah=41h "Check Extensions Present" -# int 13h ah=48h "Get Device Parameters" -# int 13h ah=08h "Legacy Get Device Parameters" -# -# A buffer of size EDDMAXNR*(EDDEXTSIZE+EDDPARMSIZE) is reserved for our use -# in the boot_params at EDDBUF. The first four bytes of which are -# used to store the device number, interface support map and version -# results from fn41. The next four bytes are used to store the legacy -# cylinders, heads, and sectors from fn08. The following 74 bytes are used to -# store the results from fn48. Starting from device 80h, fn41, then fn48 -# are called and their results stored in EDDBUF+n*(EDDEXTSIZE+EDDPARMIZE). -# Then the pointer is incremented to store the data for the next call. -# This repeats until either a device doesn't exist, or until EDDMAXNR -# devices have been stored. -# The one tricky part is that ds:si always points EDDEXTSIZE bytes into -# the structure, and the fn41 and fn08 results are stored at offsets -# from there. This removes the need to increment the pointer for -# every store, and leaves it ready for the fn48 call. -# A second one-byte buffer, EDDNR, in the boot_params stores -# the number of BIOS devices which exist, up to EDDMAXNR. -# In setup.c, copy_edd() stores both boot_params buffers away -# for later use, as they would get overwritten otherwise. -# This code is sensitive to the size of the structs in edd.h -edd_start: - # %ds points to the bootsector - # result buffer for fn48 - movw $EDDBUF+EDDEXTSIZE, %si # in ds:si, fn41 results - # kept just before that - movb $0x80, %dl # BIOS device 0x80 - -edd_check_ext: - movb $CHECKEXTENSIONSPRESENT, %ah # Function 41 - movw $EDDMAGIC1, %bx # magic - int $0x13 # make the call - jc edd_done # no more BIOS devices - - cmpw $EDDMAGIC2, %bx # is magic right? - jne edd_next # nope, next... - - movb %dl, %ds:-8(%si) # store device number - movb %ah, %ds:-7(%si) # store version - movw %cx, %ds:-6(%si) # store extensions - incb (EDDNR) # note that we stored something - -edd_get_device_params: - movw $EDDPARMSIZE, %ds:(%si) # put size - movw $0x0, %ds:2(%si) # work around buggy BIOSes - movb $GETDEVICEPARAMETERS, %ah # Function 48 - int $0x13 # make the call - # Don't check for fail return - # it doesn't matter. -edd_get_legacy_chs: - xorw %ax, %ax - movw %ax, %ds:-4(%si) - movw %ax, %ds:-2(%si) - # Ralf Brown's Interrupt List says to set ES:DI to - # 0000h:0000h "to guard against BIOS bugs" - pushw %es - movw %ax, %es - movw %ax, %di - pushw %dx # legacy call clobbers %dl - movb $LEGACYGETDEVICEPARAMETERS, %ah # Function 08 - int $0x13 # make the call - jc edd_legacy_done # failed - movb %cl, %al # Low 6 bits are max - andb $0x3F, %al # sector number - movb %al, %ds:-1(%si) # Record max sect - movb %dh, %ds:-2(%si) # Record max head number - movb %ch, %al # Low 8 bits of max cyl - shr $6, %cl - movb %cl, %ah # High 2 bits of max cyl - movw %ax, %ds:-4(%si) - -edd_legacy_done: - popw %dx - popw %es - movw %si, %ax # increment si - addw $EDDPARMSIZE+EDDEXTSIZE, %ax - movw %ax, %si - -edd_next: - incb %dl # increment to next device - cmpb $EDDMAXNR, (EDDNR) # Out of space? - jb edd_check_ext # keep looping - -edd_done: -#endif |