[U-Boot] [PATCH] malta: use unmapped flash base address

[U-Boot] [PATCH] malta: use unmapped flash base address

[Gabor Juhos]

The physical base address of the NOR flash is 0x1e000000
on the Malta boards. The hardware also maps the first 4MiB
of the flash into the 0x1fc00000-0x1fffffff range.

Currently, U-Boot uses the mapped address to access the
flash, which does not work in recent qemu versions.

Since commit a427338b222b43197c2776cbc996936df0302f51
(mips_malta: correct reading MIPS revision at 0x1fc00010)
writing to the mapped address space causes a CPU exception.
Due to the exception, U-Boot hangs during boot when it tries
to detect the CFI flash chip.

Use the correct physical address for the MALTA_FLASH_BASE
constant to avoid the problem. The change makes it possible
to start U-Boot on a Malta board emulated with Qemu 1.6.1
and 1.7.0-rc0. It also works on older versions (tested with
1.1.1, 1.2.2, 1.4.2, 1.5.3). The change is not tested on a
real Malta board.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
---
 arch/mips/include/asm/malta.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/include/asm/malta.h b/arch/mips/include/asm/malta.h
index 9b1100b..bd9043d 100644
--- a/arch/mips/include/asm/malta.h
+++ b/arch/mips/include/asm/malta.h
@@ -44,7 +44,7 @@
 #define MALTA_RESET_BASE		0x1f000500
 #define GORESET				0x42
 
-#define MALTA_FLASH_BASE		0x1fc00000
+#define MALTA_FLASH_BASE		0x1e000000
 
 #define MALTA_REVISION			0x1fc00010
 #define MALTA_REVISION_CORID_SHF	10
-- 
1.7.10

[U-Boot] [PATCH] malta: use unmapped flash base address

[Paul Burton]

On 11/11/13 14:05, Gabor Juhos wrote:
> The physical base address of the NOR flash is 0x1e000000
> on the Malta boards. The hardware also maps the first 4MiB
> of the flash into the 0x1fc00000-0x1fffffff range.
>
> Currently, U-Boot uses the mapped address to access the
> flash, which does not work in recent qemu versions.
>
> Since commit a427338b222b43197c2776cbc996936df0302f51
> (mips_malta: correct reading MIPS revision at 0x1fc00010)
> writing to the mapped address space causes a CPU exception.
> Due to the exception, U-Boot hangs during boot when it tries
> to detect the CFI flash chip.
>
> Use the correct physical address for the MALTA_FLASH_BASE
> constant to avoid the problem. The change makes it possible
> to start U-Boot on a Malta board emulated with Qemu 1.6.1
> and 1.7.0-rc0. It also works on older versions (tested with
> 1.1.1, 1.2.2, 1.4.2, 1.5.3). The change is not tested on a
> real Malta board.
>
> Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
> Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
> Cc: Paul Burton <paul.burton@imgtec.com>
> ---
>   arch/mips/include/asm/malta.h |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/mips/include/asm/malta.h b/arch/mips/include/asm/malta.h
> index 9b1100b..bd9043d 100644
> --- a/arch/mips/include/asm/malta.h
> +++ b/arch/mips/include/asm/malta.h
> @@ -44,7 +44,7 @@
>   #define MALTA_RESET_BASE		0x1f000500
>   #define GORESET				0x42
>
> -#define MALTA_FLASH_BASE		0x1fc00000
> +#define MALTA_FLASH_BASE		0x1e000000
>
>   #define MALTA_REVISION			0x1fc00010
>   #define MALTA_REVISION_CORID_SHF	10
>

Hmm, this does run on a real Malta but it takes around a minute to run 
relocate_code... With the 0x1fc00000 base address it's much faster. I'll 
see if I can figure out why...

Paul

[U-Boot] [PATCH] malta: use unmapped flash base address

[Gabor Juhos]

2013.11.11. 15:22 keltez?ssel, Paul Burton ?rta:

<...>

>> diff --git a/arch/mips/include/asm/malta.h b/arch/mips/include/asm/malta.h
>> index 9b1100b..bd9043d 100644
>> --- a/arch/mips/include/asm/malta.h
>> +++ b/arch/mips/include/asm/malta.h
>> @@ -44,7 +44,7 @@
>>   #define MALTA_RESET_BASE        0x1f000500
>>   #define GORESET                0x42
>>
>> -#define MALTA_FLASH_BASE        0x1fc00000
>> +#define MALTA_FLASH_BASE        0x1e000000
>>
>>   #define MALTA_REVISION            0x1fc00010
>>   #define MALTA_REVISION_CORID_SHF    10
>>
> 
> Hmm, this does run on a real Malta but it takes around a minute to run
> relocate_code... With the 0x1fc00000 base address it's much faster. I'll see if
> I can figure out why...

Hm, you are right. Although I did not notice that before, but with this patch
U-Boot starts slower also in qemu. It seems that the problem is in the
relocation code. I'm preparing a patch to fix that.

-Gabor