On Mar 14, 2011, at 4:37 PM, Scott Wood wrote:
On Mon, 14 Mar 2011 16:25:54 -0500 Kumar Gala galak@kernel.crashing.org wrote:
On Mar 14, 2011, at 1:09 PM, Scott Wood wrote:
On Sat, 12 Mar 2011 16:56:09 -0600 Kumar Gala galak@kernel.crashing.org wrote:
On Mar 3, 2011, at 8:59 AM, Jimi Xenidis wrote:
I was surprised to find myself at the decrement interrupt when running my new stuff. That is against ePAPR, right? Does u-boot at least make sure that the DEC is set to some large value before it leaps at me? I don't mind forcing EE=0 but I'd like to make sure I make it that far into the code :) -JX
Jimi,
Not sure how or why you are seeing this, but u-boot should disable interrupts in common/cmd_bootm.c
Look for disable_interrupts() -> this should set MSR[EE] = 0.
What about the rest of MSR -- ME/CE/DE?
I dont think we ever turn on CE in u-boot, DE would only get set in some weird external debugger build.
From arch/powerpc/cpu/mpc85xx/start.S:
/* switch back to AS = 0 */ lis r3,(MSR_CE|MSR_ME|MSR_DE)@h ori r3,r3,(MSR_CE|MSR_ME|MSR_DE)@l mtmsr r3 isync bl cpu_init_f bl board_init_f isync-Scott
commit 15fba3279b56333bdb65ead366f82c945ed320d1 Author: Kumar Gala galak@kernel.crashing.org Date: Fri Sep 11 15:28:41 2009 -0500
ppc/85xx: Disable all async interrupt sources when we boot
We should make sure to clear MSR[ME, CE, DE] when we boot an OS image since we have changed the exception vectors and the OSes vectors might not be setup we should avoid async interrupts at all costs.
Signed-off-by: Kumar Gala galak@kernel.crashing.org
diff --git a/cpu/mpc85xx/cpu_init.c b/cpu/mpc85xx/cpu_init.c index 48a82ed..a6d1e99 100644 --- a/cpu/mpc85xx/cpu_init.c +++ b/cpu/mpc85xx/cpu_init.c @@ -364,5 +364,16 @@ extern void setup_ivors(void);
void arch_preboot_os(void) { + u32 msr; + + /* + * We are changing interrupt offsets and are about to boot the OS so + * we need to make sure we disable all async interrupts. EE is already + * disabled by the time we get called. + */ + msr = mfmsr(); + msr &= ~(MSR_ME|MSR_CE|MSR_DE); + mtmsr(msr); + setup_ivors(); }
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:)
- k