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| author | Michael Brown | 2011-03-28 01:55:15 +0200 |
|---|---|---|
| committer | Michael Brown | 2011-03-28 02:00:59 +0200 |
| commit | 5924e65cea135ecac66953e583f4cf40d31d06e8 (patch) | |
| tree | 58529b82ed3a9e83604bc38f83a633ee9e7a636a /src | |
| parent | [build] Generate hybrid ISO images if isohybrid is available (diff) | |
| download | ipxe-5924e65cea135ecac66953e583f4cf40d31d06e8.tar.gz ipxe-5924e65cea135ecac66953e583f4cf40d31d06e8.tar.xz ipxe-5924e65cea135ecac66953e583f4cf40d31d06e8.zip | |
[prefix] Avoid using base memory for temporary decompression area
In the unlikely (but observable) event that INT 15,88 returns less
memory above 1MB than is required for the temporary decompression
area, ignore it and use the 1MB point anyway.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/arch/i386/prefix/libprefix.S | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/src/arch/i386/prefix/libprefix.S b/src/arch/i386/prefix/libprefix.S index 76f455862..77151a67e 100644 --- a/src/arch/i386/prefix/libprefix.S +++ b/src/arch/i386/prefix/libprefix.S @@ -753,21 +753,25 @@ payload_death_message: lcall *init_libkir_vector #else /* Find a suitable decompression temporary area, if none specified */ + pushl %eax testl %ebp, %ebp jnz 1f /* Use INT 15,88 to find the highest available address via INT * 15,88. This limits us to around 64MB, which should avoid * all of the POST-time memory map failure modes. */ - pushl %eax movb $0x88, %ah int $0x15 movw %ax, %bp addl $0x400, %ebp subl $_textdata_memsz_kb, %ebp shll $10, %ebp - popl %eax -1: + /* Sanity check: if we have ended up below 1MB, use 1MB */ + cmpl $0x100000, %ebp + jae 1f + movl $0x100000, %ebp +1: popl %eax + /* Install .text and .data to temporary area in high memory, * prior to reading the E820 memory map and relocating * properly. |