[PATCH] arm: Fix mounting root on omaps with CPU_V6 and CPU_V7
Tony Lindgren
tony at atomide.com
Mon Mar 15 18:25:43 EDT 2010
To mount root on omap2420, we need to disable VFPv3 and
HAS_TLS_REG.
VFPv3 is only available on CPU_V7. TLS_REG is only available
on ARM11 starting with r1p0 and later. As omap2420 is r0p2,
it does not have TLS_REG.
Otherwise we'll get something like this for CPUv3:
Freeing init memory: 184K
Internal error: Oops - undefined instruction: 0 [#1]
last sysfs file:
Modules linked in:
CPU: 0 Not tainted (2.6.33-rc8-07824-gf2e1d91-dirty #36)
PC is at no_old_VFP_process+0x8/0x3c
LR is at __und_usr_unknown+0x0/0x14
...
Or the system just hangs if HAS_TLS_REG is set.
Signed-off-by: Tony Lindgren <tony at atomide.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index d97d893..409ae23 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1549,7 +1549,7 @@ config VFP
config VFPv3
bool
depends on VFP
- default y if CPU_V7
+ default y if CPU_V7 && !CPU_V6
config NEON
bool "Advanced SIMD (NEON) Extension support"
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index c4ed9f9..ff0c829 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -718,11 +718,11 @@ config TLS_REG_EMUL
config HAS_TLS_REG
bool
depends on !TLS_REG_EMUL
- default y if SMP || CPU_32v7
+ default y if (SMP || CPU_32v7) && !ARCH_OMAP2
help
This selects support for the CP15 thread register.
- It is defined to be available on some ARMv6 processors (including
- all SMP capable ARMv6's) or later processors. User space may
+ It is defined to be available on some ARMv6 processors (r1p0 and
+ later, including all SMP capable ARMv6's). User space may
assume directly accessing that register and always obtain the
expected value only on ARMv7 and above.
--HTLCc13+3hfAZ6SL--
More information about the linux-arm-kernel
mailing list