VServer 1.9.2 (patch-2.6.8.1-vs1.9.2.diff)

[linux-2.6.git] / arch / i386 / boot / edd.S

diff --git a/arch/i386/boot/edd.S b/arch/i386/boot/edd.S
index faaa555..8897906 100644 (file)
--- a/arch/i386/boot/edd.S
+++ b/arch/i386/boot/edd.S
@@ -4,7 +4,7 @@
  * 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
+ *     and Andrew Wilks <Andrew_Wilks@dell.com> September 2003, June 2004
  * legacy CHS retreival by Patrick J. LoPresti <patl@users.sourceforge.net>
  *      March 2004
  */
@@ -12,28 +12,39 @@
 #include <linux/edd.h>
 
 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
-# Read the first sector of device 80h and store the 4-byte signature
+# Read the first sector of each BIOS disk device and store the 4-byte signature
+edd_mbr_sig_start:
+       movb    $0, (EDD_MBR_SIG_NR_BUF)        # zero value at EDD_MBR_SIG_NR_BUF
+       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, (DISK80_SIG_BUFFER)       # assume failure
+       movl    %eax, (%bx)                     # assume failure
+       pushw   %bx
        movb    $READ_SECTORS, %ah
        movb    $1, %al                         # read 1 sector
-       movb    $0x80, %dl                      # from device 80
        movb    $0, %dh                         # at head 0
        movw    $1, %cx                         # cylinder 0, sector 0
        pushw   %es
        pushw   %ds
        popw    %es
-       movw    $EDDBUF, %bx
-       pushw   %dx             # work around buggy BIOSes
+       movw    $EDDBUF, %bx                    # disk's data goes into EDDBUF
+       pushw   %dx             # work around buggy BIOSes
        stc                     # work around buggy BIOSes
-       int     $0x13
+       int     $0x13
        sti                     # work around buggy BIOSes
-       popw    %dx
-       jc      disk_sig_done
-       movl    (EDDBUF+MBR_SIG_OFFSET), %eax
-       movl    %eax, (DISK80_SIG_BUFFER)       # store success
-disk_sig_done:
+       popw    %dx
        popw    %es
+       popw    %bx
+       jc      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: