summaryrefslogtreecommitdiffstats
path: root/arch/arm/Kconfig
diff options
context:
space:
mode:
authorRussell King <rmk+kernel@arm.linux.org.uk>2010-09-04 10:47:48 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-10-04 20:23:36 +0100
commitf00ec48fadf5e37e7889f14cff900aa70d18b644 (patch)
tree421cbce97167a78532aa825624f380caade3c0d2 /arch/arm/Kconfig
parent067173526c3bbc2eaeefcf6b7b2a9d998b9e8042 (diff)
ARM: Allow SMP kernels to boot on UP systems
UP systems do not implement all the instructions that SMP systems have, so in order to boot a SMP kernel on a UP system, we need to rewrite parts of the kernel. Do this using an 'alternatives' scheme, where the kernel code and data is modified prior to initialization to replace the SMP instructions, thereby rendering the problematical code ineffectual. We use the linker to generate a list of 32-bit word locations and their replacement values, and run through these replacements when we detect a UP system. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/Kconfig')
-rw-r--r--arch/arm/Kconfig13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 6a939e64cbd..f6cdc21b562 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1191,6 +1191,19 @@ config SMP
If you don't know what to do here, say N.
+config SMP_ON_UP
+ bool "Allow booting SMP kernel on uniprocessor systems (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ depends on SMP && !XIP && !THUMB2_KERNEL
+ default y
+ help
+ SMP kernels contain instructions which fail on non-SMP processors.
+ Enabling this option allows the kernel to modify itself to make
+ these instructions safe. Disabling it allows about 1K of space
+ savings.
+
+ If you don't know what to do here, say Y.
+
config HAVE_ARM_SCU
bool
depends on SMP