[U-Boot] [PATCH V2] spl: Weed out CONFIG_SYS_TEXT_BASE usage

[Marek Vasut]

On 08/14/2018 11:51 AM, Simon Goldschmidt wrote:
> On Tue, Aug 14, 2018 at 11:27 AM Marek Vasut <marex at denx.de> wrote:
>>
>> The SPL loaders assume that the CONFIG_SYS_TEXT_BASE memory location
>> is available and can be corrupted by loading ie. uImage or fitImage
>> headers there. Sometimes it could be beneficial to load the headers
>> elsewhere, ie. if CONFIG_SYS_TEXT_BASE is not yet writable while we
>> still want to parse the image headers in some local onchip memory to
>> ie. extract firmware from that image.
>>
>> Add the possibility to override the location where the headers get
>> loaded by introducing new function, spl_get_load_buffer() which takes
>> two arguments -- offset from the CONFIG_SYS_TEXT_BASE and size of the
>> data that are to be loaded there -- and returns a valid buffer address
>> or hangs the system. The default behavior is the same as before, add
>> the offset to CONFIG_SYS_TEXT_BASE and return that address. User can
>> override the weak spl_get_load_buffer() function though.
>>
>> Signed-off-by: Marek Vasut <marex at denx.de>
>> Cc: Tom Rini <trini at konsulko.com>
>> ---
>> V2: Fix build issues on multiple boards due to incorrect pointer casting

[...]

>> diff --git a/common/spl/spl_ram.c b/common/spl/spl_ram.c
>> index e594beaeaa..619b39a537 100644
>> --- a/common/spl/spl_ram.c
>> +++ b/common/spl/spl_ram.c
>> @@ -63,8 +63,9 @@ static int spl_ram_load_image(struct spl_image_info *spl_image,
>>                          * No binman support or no information. For now, fix it
>>                          * to the address pointed to by U-Boot.
>>                          */
>> -                       u_boot_pos = CONFIG_SYS_TEXT_BASE -
>> -                                       sizeof(struct image_header);
>> +                       header = spl_get_load_buffer(-sizeof(*header),
>> +                                                    sizeof(*header));
>> +
> 
> Using "spl_get_load_buffer()" here seems to be a bit misleading, as
> the address is used for "execute-in-place", not for loading.

Do you have a better solution ? Instead of hard-coding the load buffer
address with some macro, this uses function which could be overridden.
Whether it's XIP or not has nothing to do with it.

>>                 }
>>                 header = (struct image_header *)map_sysmem(u_boot_pos, 0);
>>
>> diff --git a/common/spl/spl_spi.c b/common/spl/spl_spi.c
>> index ba60a3a3c5..e10cf0124f 100644
>> --- a/common/spl/spl_spi.c
>> +++ b/common/spl/spl_spi.c
>> @@ -88,8 +88,7 @@ static int spl_spi_load_image(struct spl_image_info *spl_image,
>>                 return -ENODEV;
>>         }
>>
>> -       /* use CONFIG_SYS_TEXT_BASE as temporary storage area */
>> -       header = (struct image_header *)(CONFIG_SYS_TEXT_BASE);
>> +       header = spl_get_load_buffer(-sizeof(*header), 0x40);
> 
> Shouldn't the first argument be 0 here instead of -sizeof(*header)?

No, because then the payload doesn't end up at CONFIG_SYS_TEXT_BASE .

[...]
-- 
Best regards,
Marek Vasut