* kernel decompressor problem for ARMv7 @ 2013-07-05 8:44 Lin Ming 2013-07-05 9:57 ` Will Deacon 0 siblings, 1 reply; 11+ messages in thread From: Lin Ming @ 2013-07-05 8:44 UTC (permalink / raw) To: linux-arm-kernel Hi all, I'm porting BSP code from v2.6.36 to v3.10 kernel. It's ARMv7 processor. But decompressor doesn't work. With a lot of debug, I finally find below 2 commits related. Kernel uncompress OK with these commits reverted. dbece45: ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores (Introduced in v3.6-rc6) 5010192: ARM: 7583/1: decompressor: Enable unaligned memory access for v6 and above (Introduced in v3.7-rc8) Any hint to fix it? Thanks, Lin Ming ^ permalink raw reply [flat|nested] 11+ messages in thread
* kernel decompressor problem for ARMv7 2013-07-05 8:44 kernel decompressor problem for ARMv7 Lin Ming @ 2013-07-05 9:57 ` Will Deacon 2013-07-05 16:30 ` Nicolas Pitre 2013-07-05 16:52 ` Lin Ming 0 siblings, 2 replies; 11+ messages in thread From: Will Deacon @ 2013-07-05 9:57 UTC (permalink / raw) To: linux-arm-kernel On Fri, Jul 05, 2013 at 09:44:12AM +0100, Lin Ming wrote: > Hi all, Hello, > I'm porting BSP code from v2.6.36 to v3.10 kernel. It's ARMv7 processor. Which specific processor/SoC? > But decompressor doesn't work. With a lot of debug, I finally find > below 2 commits related. > Kernel uncompress OK with these commits reverted. > > dbece45: ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores > (Introduced in v3.6-rc6) > > 5010192: ARM: 7583/1: decompressor: Enable unaligned memory access for > v6 and above > (Introduced in v3.7-rc8) > > Any hint to fix it? There's not really enough information to go on here. What specifically fails? Also, do you have to revert *both* of the above changes to get things working again? Cheers, Will ^ permalink raw reply [flat|nested] 11+ messages in thread
* kernel decompressor problem for ARMv7 2013-07-05 9:57 ` Will Deacon @ 2013-07-05 16:30 ` Nicolas Pitre 2013-07-05 16:58 ` Lin Ming 2013-07-05 16:52 ` Lin Ming 1 sibling, 1 reply; 11+ messages in thread From: Nicolas Pitre @ 2013-07-05 16:30 UTC (permalink / raw) To: linux-arm-kernel On Fri, 5 Jul 2013, Will Deacon wrote: > On Fri, Jul 05, 2013 at 09:44:12AM +0100, Lin Ming wrote: > > Hi all, > > Hello, > > > I'm porting BSP code from v2.6.36 to v3.10 kernel. It's ARMv7 processor. > > Which specific processor/SoC? > > > But decompressor doesn't work. With a lot of debug, I finally find > > below 2 commits related. > > Kernel uncompress OK with these commits reverted. > > > > dbece45: ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores > > (Introduced in v3.6-rc6) > > > > 5010192: ARM: 7583/1: decompressor: Enable unaligned memory access for > > v6 and above > > (Introduced in v3.7-rc8) > > > > Any hint to fix it? > > There's not really enough information to go on here. What specifically > fails? Also, do you have to revert *both* of the above changes to get things > working again? Also, what is the bootloader used here? Does the bootloader call the kernel with the MMU off as documented in Documentation/arm/Booting? Nicolas ^ permalink raw reply [flat|nested] 11+ messages in thread
* kernel decompressor problem for ARMv7 2013-07-05 16:30 ` Nicolas Pitre @ 2013-07-05 16:58 ` Lin Ming 2013-07-08 2:27 ` Lin Ming 0 siblings, 1 reply; 11+ messages in thread From: Lin Ming @ 2013-07-05 16:58 UTC (permalink / raw) To: linux-arm-kernel On Sat, Jul 6, 2013 at 12:30 AM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: > On Fri, 5 Jul 2013, Will Deacon wrote: > >> On Fri, Jul 05, 2013 at 09:44:12AM +0100, Lin Ming wrote: >> > Hi all, >> >> Hello, >> >> > I'm porting BSP code from v2.6.36 to v3.10 kernel. It's ARMv7 processor. >> >> Which specific processor/SoC? >> >> > But decompressor doesn't work. With a lot of debug, I finally find >> > below 2 commits related. >> > Kernel uncompress OK with these commits reverted. >> > >> > dbece45: ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores >> > (Introduced in v3.6-rc6) >> > >> > 5010192: ARM: 7583/1: decompressor: Enable unaligned memory access for >> > v6 and above >> > (Introduced in v3.7-rc8) >> > >> > Any hint to fix it? >> >> There's not really enough information to go on here. What specifically >> fails? Also, do you have to revert *both* of the above changes to get things >> working again? > > Also, what is the bootloader used here? uboot. > > Does the bootloader call the kernel with the MMU off as documented in > Documentation/arm/Booting? How to check this? I'll check uboot code or add debug code in boot/compressed/head.S to check it next Monday. > > Nicolas ^ permalink raw reply [flat|nested] 11+ messages in thread
* kernel decompressor problem for ARMv7 2013-07-05 16:58 ` Lin Ming @ 2013-07-08 2:27 ` Lin Ming 2013-07-09 1:09 ` Lin Ming 0 siblings, 1 reply; 11+ messages in thread From: Lin Ming @ 2013-07-08 2:27 UTC (permalink / raw) To: linux-arm-kernel On Sat, 2013-07-06 at 00:58 +0800, Lin Ming wrote: > On Sat, Jul 6, 2013 at 12:30 AM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: > > On Fri, 5 Jul 2013, Will Deacon wrote: > > > >> On Fri, Jul 05, 2013 at 09:44:12AM +0100, Lin Ming wrote: > >> > Hi all, > >> > >> Hello, > >> > >> > I'm porting BSP code from v2.6.36 to v3.10 kernel. It's ARMv7 processor. > >> > >> Which specific processor/SoC? > >> > >> > But decompressor doesn't work. With a lot of debug, I finally find > >> > below 2 commits related. > >> > Kernel uncompress OK with these commits reverted. > >> > > >> > dbece45: ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores > >> > (Introduced in v3.6-rc6) > >> > > >> > 5010192: ARM: 7583/1: decompressor: Enable unaligned memory access for > >> > v6 and above > >> > (Introduced in v3.7-rc8) > >> > > >> > Any hint to fix it? > >> > >> There's not really enough information to go on here. What specifically > >> fails? Also, do you have to revert *both* of the above changes to get things > >> working again? > > > > Also, what is the bootloader used here? > > uboot. > > > > > Does the bootloader call the kernel with the MMU off as documented in > > Documentation/arm/Booting? > > How to check this? > > I'll check uboot code or add debug code in boot/compressed/head.S to > check it next Monday. I added below debug code to print the control reg from lowest 4bits to highest 4bits. It prints "B7805C". So the control reg is 0x00c5087b. Seems bootloader calls the kernel with MMU enabled and Alignment fault checking enabled. diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 32337ff..9434720 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -125,6 +125,23 @@ .rept 7 mov r0, r0 .endr + + /* Dirty debug code to print control reg from lowest 4bits to highest 4bits */ + ldr r2, =0xf0070120 @ UART + mrc p15, 0, r0, c1, c0, 0 @ read control reg + 1: + cmp r0, #0 + beq 2f + and r1, r0, #15 + cmp r1, #9 + addgt r1, r1, #7 + add r1, r1, #48 + str r1, [r2] + asr r0, r0, #4 + b 1b + 2: + + ARM( mov r0, r0 ) ARM( b 1f ) THUMB( adr r12, BSYM(1f) ) > > > > > Nicolas ^ permalink raw reply related [flat|nested] 11+ messages in thread
* kernel decompressor problem for ARMv7 2013-07-08 2:27 ` Lin Ming @ 2013-07-09 1:09 ` Lin Ming 2013-07-09 7:39 ` Nicolas Pitre 0 siblings, 1 reply; 11+ messages in thread From: Lin Ming @ 2013-07-09 1:09 UTC (permalink / raw) To: linux-arm-kernel On Mon, Jul 8, 2013 at 10:27 AM, Lin Ming <minggr@gmail.com> wrote: > On Sat, 2013-07-06 at 00:58 +0800, Lin Ming wrote: >> On Sat, Jul 6, 2013 at 12:30 AM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: >> > On Fri, 5 Jul 2013, Will Deacon wrote: >> > >> >> On Fri, Jul 05, 2013 at 09:44:12AM +0100, Lin Ming wrote: >> >> > Hi all, >> >> >> >> Hello, >> >> >> >> > I'm porting BSP code from v2.6.36 to v3.10 kernel. It's ARMv7 processor. >> >> >> >> Which specific processor/SoC? >> >> >> >> > But decompressor doesn't work. With a lot of debug, I finally find >> >> > below 2 commits related. >> >> > Kernel uncompress OK with these commits reverted. >> >> > >> >> > dbece45: ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores >> >> > (Introduced in v3.6-rc6) >> >> > >> >> > 5010192: ARM: 7583/1: decompressor: Enable unaligned memory access for >> >> > v6 and above >> >> > (Introduced in v3.7-rc8) >> >> > >> >> > Any hint to fix it? >> >> >> >> There's not really enough information to go on here. What specifically >> >> fails? Also, do you have to revert *both* of the above changes to get things >> >> working again? >> > >> > Also, what is the bootloader used here? >> >> uboot. >> >> > >> > Does the bootloader call the kernel with the MMU off as documented in >> > Documentation/arm/Booting? >> >> How to check this? >> >> I'll check uboot code or add debug code in boot/compressed/head.S to >> check it next Monday. > > I added below debug code to print the control reg from lowest 4bits to > highest 4bits. > > It prints "B7805C". So the control reg is 0x00c5087b. > Seems bootloader calls the kernel with MMU enabled and Alignment fault > checking enabled. Hi Nicolas, Is this information useful? Or any other information needed for further debug? Thanks, Lin Ming > > diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S > index 32337ff..9434720 100644 > --- a/arch/arm/boot/compressed/head.S > +++ b/arch/arm/boot/compressed/head.S > @@ -125,6 +125,23 @@ > .rept 7 > mov r0, r0 > .endr > + > + /* Dirty debug code to print control reg from lowest 4bits to highest 4bits */ > + ldr r2, =0xf0070120 @ UART > + mrc p15, 0, r0, c1, c0, 0 @ read control reg > + 1: > + cmp r0, #0 > + beq 2f > + and r1, r0, #15 > + cmp r1, #9 > + addgt r1, r1, #7 > + add r1, r1, #48 > + str r1, [r2] > + asr r0, r0, #4 > + b 1b > + 2: > + > + > ARM( mov r0, r0 ) > ARM( b 1f ) > THUMB( adr r12, BSYM(1f) ) > > >> >> > >> > Nicolas > > ^ permalink raw reply [flat|nested] 11+ messages in thread
* kernel decompressor problem for ARMv7 2013-07-09 1:09 ` Lin Ming @ 2013-07-09 7:39 ` Nicolas Pitre 2013-07-09 7:53 ` Lin Ming 0 siblings, 1 reply; 11+ messages in thread From: Nicolas Pitre @ 2013-07-09 7:39 UTC (permalink / raw) To: linux-arm-kernel On Tue, 9 Jul 2013, Lin Ming wrote: > On Mon, Jul 8, 2013 at 10:27 AM, Lin Ming <minggr@gmail.com> wrote: > > On Sat, 2013-07-06 at 00:58 +0800, Lin Ming wrote: > >> On Sat, Jul 6, 2013 at 12:30 AM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: > >> > On Fri, 5 Jul 2013, Will Deacon wrote: > >> > > >> >> On Fri, Jul 05, 2013 at 09:44:12AM +0100, Lin Ming wrote: > >> >> > Hi all, > >> >> > >> >> Hello, > >> >> > >> >> > I'm porting BSP code from v2.6.36 to v3.10 kernel. It's ARMv7 processor. > >> >> > >> >> Which specific processor/SoC? > >> >> > >> >> > But decompressor doesn't work. With a lot of debug, I finally find > >> >> > below 2 commits related. > >> >> > Kernel uncompress OK with these commits reverted. > >> >> > > >> >> > dbece45: ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores > >> >> > (Introduced in v3.6-rc6) > >> >> > > >> >> > 5010192: ARM: 7583/1: decompressor: Enable unaligned memory access for > >> >> > v6 and above > >> >> > (Introduced in v3.7-rc8) > >> >> > > >> >> > Any hint to fix it? > >> >> > >> >> There's not really enough information to go on here. What specifically > >> >> fails? Also, do you have to revert *both* of the above changes to get things > >> >> working again? > >> > > >> > Also, what is the bootloader used here? > >> > >> uboot. > >> > >> > > >> > Does the bootloader call the kernel with the MMU off as documented in > >> > Documentation/arm/Booting? > >> > >> How to check this? > >> > >> I'll check uboot code or add debug code in boot/compressed/head.S to > >> check it next Monday. > > > > I added below debug code to print the control reg from lowest 4bits to > > highest 4bits. > > > > It prints "B7805C". So the control reg is 0x00c5087b. > > Seems bootloader calls the kernel with MMU enabled and Alignment fault > > checking enabled. > > Hi Nicolas, > > Is this information useful? > Or any other information needed for further debug? No more info needed. The kernel has to be booted with the MMU disabled as per the booting protocol documentation. You therefore have to fix your bootloader. Nicolas ^ permalink raw reply [flat|nested] 11+ messages in thread
* kernel decompressor problem for ARMv7 2013-07-09 7:39 ` Nicolas Pitre @ 2013-07-09 7:53 ` Lin Ming 2013-07-09 8:05 ` Will Deacon 0 siblings, 1 reply; 11+ messages in thread From: Lin Ming @ 2013-07-09 7:53 UTC (permalink / raw) To: linux-arm-kernel On Tue, Jul 9, 2013 at 3:39 PM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: > On Tue, 9 Jul 2013, Lin Ming wrote: > >> On Mon, Jul 8, 2013 at 10:27 AM, Lin Ming <minggr@gmail.com> wrote: >> > On Sat, 2013-07-06 at 00:58 +0800, Lin Ming wrote: >> >> On Sat, Jul 6, 2013 at 12:30 AM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: >> >> > On Fri, 5 Jul 2013, Will Deacon wrote: >> >> > >> >> >> On Fri, Jul 05, 2013 at 09:44:12AM +0100, Lin Ming wrote: >> >> >> > Hi all, >> >> >> >> >> >> Hello, >> >> >> >> >> >> > I'm porting BSP code from v2.6.36 to v3.10 kernel. It's ARMv7 processor. >> >> >> >> >> >> Which specific processor/SoC? >> >> >> >> >> >> > But decompressor doesn't work. With a lot of debug, I finally find >> >> >> > below 2 commits related. >> >> >> > Kernel uncompress OK with these commits reverted. >> >> >> > >> >> >> > dbece45: ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores >> >> >> > (Introduced in v3.6-rc6) >> >> >> > >> >> >> > 5010192: ARM: 7583/1: decompressor: Enable unaligned memory access for >> >> >> > v6 and above >> >> >> > (Introduced in v3.7-rc8) >> >> >> > >> >> >> > Any hint to fix it? >> >> >> >> >> >> There's not really enough information to go on here. What specifically >> >> >> fails? Also, do you have to revert *both* of the above changes to get things >> >> >> working again? >> >> > >> >> > Also, what is the bootloader used here? >> >> >> >> uboot. >> >> >> >> > >> >> > Does the bootloader call the kernel with the MMU off as documented in >> >> > Documentation/arm/Booting? >> >> >> >> How to check this? >> >> >> >> I'll check uboot code or add debug code in boot/compressed/head.S to >> >> check it next Monday. >> > >> > I added below debug code to print the control reg from lowest 4bits to >> > highest 4bits. >> > >> > It prints "B7805C". So the control reg is 0x00c5087b. >> > Seems bootloader calls the kernel with MMU enabled and Alignment fault >> > checking enabled. >> >> Hi Nicolas, >> >> Is this information useful? >> Or any other information needed for further debug? > > No more info needed. The kernel has to be booted with the MMU disabled > as per the booting protocol documentation. You therefore have to fix > your > bootloader. OK. But I have to also revert below commit to make decompressor work. commit 5010192: ARM: 7583/1: decompressor: Enable unaligned memory access for v6 and above It seems like caused by bootloader has Alignment fault checking enabled. Any suggestion how to fix it? Thanks. > > > Nicolas ^ permalink raw reply [flat|nested] 11+ messages in thread
* kernel decompressor problem for ARMv7 2013-07-09 7:53 ` Lin Ming @ 2013-07-09 8:05 ` Will Deacon 2013-07-09 8:21 ` Lin Ming 0 siblings, 1 reply; 11+ messages in thread From: Will Deacon @ 2013-07-09 8:05 UTC (permalink / raw) To: linux-arm-kernel On Tue, Jul 09, 2013 at 08:53:05AM +0100, Lin Ming wrote: > On Tue, Jul 9, 2013 at 3:39 PM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: > > No more info needed. The kernel has to be booted with the MMU disabled > > as per the booting protocol documentation. You therefore have to fix > > your > > bootloader. > > OK. > > But I have to also revert below commit to make decompressor work. > > commit 5010192: > ARM: 7583/1: decompressor: Enable unaligned memory access for v6 and above > > It seems like caused by bootloader has Alignment fault checking enabled. > Any suggestion how to fix it? Well step 1 is to disable the MMU. Once you've done that, you really don't want to be issuing unaligned accesses (since memory will be treated as strongly-ordered), so the value of the alignment trap bit is irrelevant. Will ^ permalink raw reply [flat|nested] 11+ messages in thread
* kernel decompressor problem for ARMv7 2013-07-09 8:05 ` Will Deacon @ 2013-07-09 8:21 ` Lin Ming 0 siblings, 0 replies; 11+ messages in thread From: Lin Ming @ 2013-07-09 8:21 UTC (permalink / raw) To: linux-arm-kernel On Tue, Jul 9, 2013 at 4:05 PM, Will Deacon <will.deacon@arm.com> wrote: > On Tue, Jul 09, 2013 at 08:53:05AM +0100, Lin Ming wrote: >> On Tue, Jul 9, 2013 at 3:39 PM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: >> > No more info needed. The kernel has to be booted with the MMU disabled >> > as per the booting protocol documentation. You therefore have to fix >> > your >> > bootloader. >> >> OK. >> >> But I have to also revert below commit to make decompressor work. >> >> commit 5010192: >> ARM: 7583/1: decompressor: Enable unaligned memory access for v6 and above >> >> It seems like caused by bootloader has Alignment fault checking enabled. >> Any suggestion how to fix it? > > Well step 1 is to disable the MMU. Once you've done that, you really don't > want to be issuing unaligned accesses (since memory will be treated as > strongly-ordered), so the value of the alignment trap bit is irrelevant. Thanks. Will try it. > > Will ^ permalink raw reply [flat|nested] 11+ messages in thread
* kernel decompressor problem for ARMv7 2013-07-05 9:57 ` Will Deacon 2013-07-05 16:30 ` Nicolas Pitre @ 2013-07-05 16:52 ` Lin Ming 1 sibling, 0 replies; 11+ messages in thread From: Lin Ming @ 2013-07-05 16:52 UTC (permalink / raw) To: linux-arm-kernel On Fri, Jul 5, 2013 at 5:57 PM, Will Deacon <will.deacon@arm.com> wrote: > On Fri, Jul 05, 2013 at 09:44:12AM +0100, Lin Ming wrote: >> Hi all, > > Hello, > >> I'm porting BSP code from v2.6.36 to v3.10 kernel. It's ARMv7 processor. > > Which specific processor/SoC? Cortex-A9 CPU on Cortina-Systems Baseboard > >> But decompressor doesn't work. With a lot of debug, I finally find >> below 2 commits related. >> Kernel uncompress OK with these commits reverted. >> >> dbece45: ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores >> (Introduced in v3.6-rc6) >> >> 5010192: ARM: 7583/1: decompressor: Enable unaligned memory access for >> v6 and above >> (Introduced in v3.7-rc8) >> >> Any hint to fix it? > > There's not really enough information to go on here. What specifically > fails? Also, do you have to revert *both* of the above changes to get things > working again? The "fails" is that the decompressor code never get called. U-Boot prints "Starting kernel", then the board just hang there. Yes, need to revert *both*. > > Cheers, > > Will ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2013-07-09 8:21 UTC | newest] Thread overview: 11+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2013-07-05 8:44 kernel decompressor problem for ARMv7 Lin Ming 2013-07-05 9:57 ` Will Deacon 2013-07-05 16:30 ` Nicolas Pitre 2013-07-05 16:58 ` Lin Ming 2013-07-08 2:27 ` Lin Ming 2013-07-09 1:09 ` Lin Ming 2013-07-09 7:39 ` Nicolas Pitre 2013-07-09 7:53 ` Lin Ming 2013-07-09 8:05 ` Will Deacon 2013-07-09 8:21 ` Lin Ming 2013-07-05 16:52 ` Lin Ming
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