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| author | Michael Brown | 2009-02-15 12:42:15 +0100 |
|---|---|---|
| committer | Michael Brown | 2009-02-15 12:44:21 +0100 |
| commit | f16668dd600c266ee573badc295745cbb0c0f879 (patch) | |
| tree | 29671e6e4fc432bc852f3676fb57e2a4b9c35068 | |
| parent | [build] Treat warnings as errors in assembly files (diff) | |
| download | ipxe-f16668dd600c266ee573badc295745cbb0c0f879.tar.gz ipxe-f16668dd600c266ee573badc295745cbb0c0f879.tar.xz ipxe-f16668dd600c266ee573badc295745cbb0c0f879.zip | |
[romprefix] Update ROM checksum even if PMM allocation fails
There are code paths other than PMM allocation that can result in our
changing the ROM checksum. For example, we attempt to update our
product string to incorporate the PCI bus:dev.fn number. In a system
that does not support PMM, we could therefore end up with an incorrect
checksum.
Fix by attempting to update the checksum unconditionally.
| -rw-r--r-- | src/arch/i386/prefix/romprefix.S | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/src/arch/i386/prefix/romprefix.S b/src/arch/i386/prefix/romprefix.S index d248916d..2664e340 100644 --- a/src/arch/i386/prefix/romprefix.S +++ b/src/arch/i386/prefix/romprefix.S @@ -345,20 +345,22 @@ got_pmm: /* PMM allocation succeeded */ shll $9, %ecx addr32 rep movsb /* PMM presence implies flat real mode */ movl %edi, decompress_to - /* Shrink ROM and update checksum */ + /* Shrink ROM */ + movb $_prefix_memsz_sect, romheader_size +pmm_fail: + /* Restore upper register halves */ + popal +no_pmm: + + /* Update checksum */ xorw %bx, %bx xorw %si, %si - movw $_prefix_memsz_sect, %cx - movb %cl, romheader_size + movzbw romheader_size, %cx shlw $9, %cx 1: lodsb addb %al, %bl loop 1b subb %bl, checksum -pmm_fail: - /* Restore upper register halves */ - popal -no_pmm: /* Copy self to option ROM space. Required for PCI3.0, which * loads us to a temporary location in low memory. Will be a |