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| author | Jan Beulich <JBeulich@suse.com> | 2012-05-31 10:18:13 +0200 |
|---|---|---|
| committer | Jan Beulich <JBeulich@suse.com> | 2012-05-31 10:18:13 +0200 |
| commit | 9f78a9e4d9a64d75ef74b2ebbde7b79ba4045381 (patch) | |
| tree | 58e1f51777587b24f8b28a2c074737edb01b786e /xen/arch/x86/boot | |
| parent | ef4abe73e1a406fa1a9733324d1d5224241db38b (diff) | |
| download | xen-9f78a9e4d9a64d75ef74b2ebbde7b79ba4045381.tar.gz xen-9f78a9e4d9a64d75ef74b2ebbde7b79ba4045381.tar.bz2 xen-9f78a9e4d9a64d75ef74b2ebbde7b79ba4045381.zip | |
x86/EDD: check MBR for BIOS magic before considering signature valid
Signed-off-by: Jan Beulich <JBeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Diffstat (limited to 'xen/arch/x86/boot')
| -rw-r--r-- | xen/arch/x86/boot/edd.S | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/xen/arch/x86/boot/edd.S b/xen/arch/x86/boot/edd.S index 59874ce4c6..2c8df8ccc8 100644 --- a/xen/arch/x86/boot/edd.S +++ b/xen/arch/x86/boot/edd.S @@ -53,12 +53,16 @@ edd_mbr_sig_read: 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. + cmpw $0xaa55, bootsym(boot_edd_info)+0x1fe + jne .Ledd_mbr_sig_next movl bootsym(boot_edd_info)+EDD_MBR_SIG_OFFSET,%eax movb %dl, (%bx) # store BIOS drive number movl %eax, 4(%bx) # store signature from MBR incb bootsym(boot_mbr_signature_nr) # note that we stored something - incb %dl # increment to next device addw $8, %bx # increment sig buffer ptr +.Ledd_mbr_sig_next: + incb %dl # increment to next device + jz edd_mbr_sig_done cmpb $EDD_MBR_SIG_MAX,bootsym(boot_mbr_signature_nr) jb edd_mbr_sig_read edd_mbr_sig_done: |