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authorH. Peter Anvin2011-04-25 23:52:37 +0200
committerH. Peter Anvin2011-04-25 23:52:37 +0200
commit39b68976ac653cfdc7f872a293e8b7928de2dcc6 (patch)
treecaf1d25a448fdf56878de7fb700b26655676ca0d
parentMerge branch 'dcache-cleanup' (diff)
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x86, setup: When probing memory with e801, use ax/bx as a pair
When we use BIOS function e801 to probe memory, we should use ax/bx (or cx/dx) as a pair, not mix and match. This was a typo during the translation from assembly code, and breaks at least one set of machines in the field (which return cx = dx = 0). Reported-and-tested-by: Chris Samuel <chris@csamuel.org> Fix-proposed-by: Thomas Meyer <thomas@m3y3r.de> Link: http://lkml.kernel.org/r/1303566747.12067.10.camel@localhost.localdomain
-rw-r--r--arch/x86/boot/memory.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/boot/memory.c b/arch/x86/boot/memory.c
index cae3feb1035e..db75d07c3645 100644
--- a/arch/x86/boot/memory.c
+++ b/arch/x86/boot/memory.c
@@ -91,7 +91,7 @@ static int detect_memory_e801(void)
if (oreg.ax > 15*1024) {
return -1; /* Bogus! */
} else if (oreg.ax == 15*1024) {
- boot_params.alt_mem_k = (oreg.dx << 6) + oreg.ax;
+ boot_params.alt_mem_k = (oreg.bx << 6) + oreg.ax;
} else {
/*
* This ignores memory above 16MB if we have a memory