Re: [BUG] x86 kenel won't boot under Virtual PC

From: David Sanders
Date: Sun Sep 07 2008 - 19:22:55 EST


On Friday 05 September 2008 19:31, H. Peter Anvin wrote:
> David Sanders wrote:
> > I recently discovered that x86 kernels won't boot under Virtual PC. In
>
> Could you please confirm if the tip kernel solves the problem?
>

Yes the patch you supplied (and now in Linus's tree) fixes (part) of the problem.
In order to get a working kernel I also need a patch for the nops.h issue.
I have tested and confirmed that the patch posted by Linus works and finally
solves the problem with virtual PC.

Linus please apply your patch (which I quote below).
---
arch/x86/Kconfig.cpu | 13 ++++++++-----
1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 2c518fb..b225219 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -382,14 +382,17 @@ config X86_OOSTORE
# P6_NOPs are a relatively minor optimization that require a family >=
# 6 processor, except that it is broken on certain VIA chips.
# Furthermore, AMD chips prefer a totally different sequence of NOPs
-# (which work on all CPUs). As a result, disallow these if we're
-# compiling X86_GENERIC but not X86_64 (these NOPs do work on all
-# x86-64 capable chips); the list of processors in the right-hand clause
-# are the cores that benefit from this optimization.
+# (which work on all CPUs). In addition, it looks like Virtual PC
+# does not understand them.
+#
+# As a result, disallow these if we're not compiling for X86_64 (these
+# NOPs do work on all x86-64 capable chips); the list of processors in
+# the right-hand clause are the cores that benefit from this optimization.
#
config X86_P6_NOP
def_bool y
- depends on (X86_64 || !X86_GENERIC) && (M686 || MPENTIUMII || MPENTIUMIII || MPENTIUMM || MCORE2 || MPENTIUM4 || MPSC)
+ depends on X86_64
+ depends on (MCORE2 || MPENTIUM4 || MPSC)

config X86_TSC
def_bool y



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