[PATCH] Modify raspberrypi mm_config_table to map GPIO and registers.

Hesham Moustafa heshamelmatary at gmail.com
Tue Oct 15 20:04:31 UTC 2013


On Tue, Oct 15, 2013 at 1:39 AM, Chris Johns <chrisj at rtems.org> wrote:

> Hesham Moustafa wrote:
>
>>
>> On Mon, Oct 14, 2013 at 4:02 PM, Sebastian Huber
>> <sebastian.huber at embedded-**brains.de<sebastian.huber at embedded-brains.de>
>> <mailto:sebastian.huber@**embedded-brains.de<sebastian.huber at embedded-brains.de>>>
>> wrote:
>>
>>     On 2013-10-14 15:34, Hesham AL-Matary wrote:
>>
>>         diff --git
>>         a/c/src/lib/libbsp/arm/__**raspberrypi/startup/mm_config_**
>> __table.c
>>         b/c/src/lib/libbsp/arm/__**raspberrypi/startup/mm_config_**
>> __table.c
>>         index 5436a76..2b748b2 100644
>>         --- a/c/src/lib/libbsp/arm/__**raspberrypi/startup/mm_config_**
>> __table.c
>>         +++ b/c/src/lib/libbsp/arm/__**raspberrypi/startup/mm_config_**
>> __table.c
>>
>>         @@ -42,7 +42,7 @@ bsp_mm_config_table[] = {
>>              }, {
>>                .begin = (uint32_t) bsp_section_text_begin,
>>                .end = (uint32_t) bsp_section_text_end,
>>         -    .flags = ARMV7_MMU_CODE_CACHED
>>         +    .flags = ARMV7_MMU_READ_WRITE
>>
>>
>>     What is the problem with the cache?  Did the cache previously work?
>>
>> There is a problem with applying a Read-Only permissions in general to
>> this
>> area for RaspberryPi BSP.
>>
>>
> What is the reason ?
> I am not sure about that.
>
>
>>
>>              }, {
>>                .begin = (uint32_t) bsp_section_rodata_begin,
>>                .end = (uint32_t) bsp_section_rodata_end,
>>         @@ -63,8 +63,12 @@ bsp_mm_config_table[] = {
>>                .begin = (uint32_t) bsp_section_stack_begin,
>>                .end = (uint32_t) bsp_section_stack_end,
>>                .flags = MMU_DATA_READ_WRITE
>>         +  }, {
>>         +    .begin = 0x20000000,
>>         +    .end = 0x20FFFFFF,
>>         +    .flags = ARMV7_MMU_DATA_READ_WRITE
>>
>>
>>     What is this for an area?
>>
>> It's for Raspberry GPIO pins and other registers (defined at
>> raspbberrypi.h).
>>
>>
> Should this be ARMV7_MMU_DEVICE and not ARMV7_MMU_DATA_READ_WRITE ?

 Both works fine. I noticed that other folks map this area as rw (via
mman.h) on raspberrypi OS.

>
>
> Chris
>
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