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[PATCH 0/1] ARM: pxa168: fix corrected reset vector

Previous thread: [PATCH] ARM: pxa3xx: fix build error when CONFIG_MTD_PARTITIONS is not defined by Mark F. Brown on Thursday, August 26, 2010 - 1:56 am. (5 messages)

Next thread: [PATCH 0/5] ARM: pxa168: add keypad support by Mark F. Brown on Thursday, August 26, 2010 - 2:18 am. (17 messages)
[view original message]
From: Mark F. Brown
Subject: [PATCH 0/1] ARM: pxa168: fix corrected reset vector
Date: Thursday, August 26, 2010 - 2:07 am

Reset vector for pxa168 is 0xffff_0000 not 0x0
This fix allows reboot to work

Mark F. Brown (1):
  ARM: pxa168: fix corrected reset vector

 arch/arm/mach-mmp/include/mach/system.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

--


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[view original message]
From: Mark F. Brown
Subject: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Thursday, August 26, 2010 - 2:07 am

Signed-off-by: Mark F. Brown <mark.brown314@gmail.com>
---
 arch/arm/mach-mmp/include/mach/system.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-mmp/include/mach/system.h b/arch/arm/mach-mmp/include/mach/system.h
index 4f5b0e0..926e9c0 100644
--- a/arch/arm/mach-mmp/include/mach/system.h
+++ b/arch/arm/mach-mmp/include/mach/system.h
@@ -16,6 +16,6 @@ static inline void arch_idle(void)
 
 static inline void arch_reset(char mode, const char *cmd)
 {
-	cpu_reset(0);
+	cpu_reset(0xffff0000);
 }
 #endif /* __ASM_MACH_SYSTEM_H */
-- 
1.7.0.4

--


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[view original message]
From: Eric Miao
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Monday, August 30, 2010 - 10:48 pm

Not sure if this correct. But normally reset jump happens after we turn
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[view original message]
From: Mark F. Brown
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Monday, August 30, 2010 - 11:02 pm

Eric, the boot-rom for pxa168 starts at 0xffff_0000. I am pretty sure
about that! If you set the reset vector to 0x0 it will crash during
reboot. I will send you xdb snapshots if you need me to.

Regards,
-- Mark
--


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[view original message]
From: Eric Miao
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Monday, August 30, 2010 - 11:04 pm

OK, you are expert on this :-)

Applied to 'fix'.
--


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[view original message]
From: Eric Miao
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Monday, August 30, 2010 - 11:08 pm

One moment. Since this is really global to pxa910 and mmp2, so I
suggest this being fixed for pxa168 only first. How about this:

    ARM: pxa168: fix corrected reset vector

    Reset vector for pxa168 is 0xffff_0000 not 0x0. This fix allows
    reboot to work

    Signed-off-by: Mark F. Brown <mark.brown314@gmail.com>

diff --git a/arch/arm/mach-mmp/include/mach/system.h
b/arch/arm/mach-mmp/include/mach/system.h
index 4f5b0e0..1a8a25e 100644
--- a/arch/arm/mach-mmp/include/mach/system.h
+++ b/arch/arm/mach-mmp/include/mach/system.h
@@ -9,6 +9,8 @@
 #ifndef __ASM_MACH_SYSTEM_H
 #define __ASM_MACH_SYSTEM_H

+#include <mach/cputype.h>
+
 static inline void arch_idle(void)
 {
 	cpu_do_idle();
@@ -16,6 +18,9 @@ static inline void arch_idle(void)

 static inline void arch_reset(char mode, const char *cmd)
 {
-	cpu_reset(0);
+	if (cpu_is_pxa168())
+		cpu_reset(0xffff0000);
+	else
+		cpu_reset(0);
 }
 #endif /* __ASM_MACH_SYSTEM_H */
--


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[view original message]
From: Haojian Zhuang
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Monday, August 30, 2010 - 11:26 pm

The reset code is in below.

	.align	5
ENTRY(cpu_mohawk_reset)
	mov	ip, #0
	mcr	p15, 0, ip, c7, c7, 0		@ invalidate I,D caches
	mcr	p15, 0, ip, c7, c10, 4		@ drain WB
	mcr	p15, 0, ip, c8, c7, 0		@ invalidate I & D TLBs
	mrc	p15, 0, ip, c1, c0, 0		@ ctrl register
	bic	ip, ip, #0x0007			@ .............cam
	bic	ip, ip, #0x1100			@ ...i...s........
	mcr	p15, 0, ip, c1, c0, 0		@ ctrl register
	mov	pc, r0

MMU is disabled at here and replace PC with r0 value. I doubt code
executed correctly at here. While MMU is disabled, the PC should be
continue in the range of 0xCxxx_xxxx (kernel space). "mov pc, r0"
shouldn't be executed. Instruction fetch failure should occurs since
there's no physical address in 0xCxxx_xxxx.

Correct me if I'm wrong.

Thanks
Haojian
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[view original message]
From: Mark F. Brown
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Monday, August 30, 2010 - 11:48 pm

On Tue, Aug 31, 2010 at 2:26 AM, Haojian Zhuang

Haojian,

I think there is a pipeline execution of the mov pc, r0 instruction.
If I remember correctly you need to do a similar jump when you turn
the MMU on in early boot code. If it makes any difference I did test
this code on pxa168 before submitting it. I will double check the mmp2
and the pxa910 reset vectors with the Boot ROM developers.
--


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[view original message]
From: Eric Miao
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Monday, August 30, 2010 - 11:54 pm

It does depend on the prefetch unit for that. So the branch instruction
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[view original message]
From: Haojian Zhuang
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Tuesday, August 31, 2010 - 12:02 am

In early boot code, 1:1 (physical:virtual) mapping is used. It means
that physical address is same as virtual address. So you can operature
mmu as you wish.

By the way, I don't suggest to reset CPU by this way. Reset is not
only make code running from the head, it should also clear registers
and RTL logic in CPU.
--


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[view original message]
From: Eric Miao
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Tuesday, August 31, 2010 - 12:08 am

On Tue, Aug 31, 2010 at 3:02 PM, Haojian Zhuang

Depends on if pxa168 has a reset signal asserted from internal or from
external GPIO, which is controllable from the CPU itself. That's what
pxa is doing at this moment.
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[view original message]
From: Haojian Zhuang
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Tuesday, August 31, 2010 - 12:21 am

Yes, it depends on reset signal. Watchdog timer is built in pxa168. So
I think that watchdog reset could be better.
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[view original message]
From: Eric Miao
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Tuesday, August 31, 2010 - 12:27 am

On Tue, Aug 31, 2010 at 3:21 PM, Haojian Zhuang

Haojian, note we have a reboot mode, so possibly will have to implement
all of them if capable.
--


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[view original message]
From: Mark F. Brown
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Tuesday, August 31, 2010 - 12:28 am

On Tue, Aug 31, 2010 at 3:21 AM, Haojian Zhuang

Haojian,

That is true, I am planning to send an update to support watchdog
timer reset soon. The problem is I need to test pxa910 and mmp2 as
well and determine if the watchdog reset code is consistent. It was
simpler for me to just fix this at the moment.
--


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[view original message]
From: Eric Miao
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Tuesday, August 31, 2010 - 12:28 am

This fix can go ahead in my POV.
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[view original message]
From: Mark F. Brown
Subject: Re: [PATCH 1/1] ARM: pxa168: fix corrected reset vector
Date: Tuesday, August 31, 2010 - 12:24 am

That will work!

-- Mark
--


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Previous thread: [PATCH] ARM: pxa3xx: fix build error when CONFIG_MTD_PARTITIONS is not defined by Mark F. Brown on Thursday, August 26, 2010 - 1:56 am. (5 messages)

Next thread: [PATCH 0/5] ARM: pxa168: add keypad support by Mark F. Brown on Thursday, August 26, 2010 - 2:18 am. (17 messages)