Re: [PATCH edk2-platforms 2/2] Silicon/NorFlashSynQuacerLib: describe entire firmware region as FV

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 13 June 2018 at 12:00, Leif Lindholm <leif.lindholm@linaro.org> wrote:
> On Wed, Jun 13, 2018 at 09:19:01AM +0200, Ard Biesheuvel wrote:
>> On 13 June 2018 at 00:59, Leif Lindholm <leif.lindholm@linaro.org> wrote:
>> > On Thu, Jun 07, 2018 at 05:08:18PM +0200, Ard Biesheuvel wrote:
>> >> In order to allow for more flexibility when updating parts of the
>> >> firmware via capsule update, expand the description of the code FV
>> >> to cover the entire 4 MB region at the base of the NOR flash.
>> >>
>> >> Contributed-under: TianoCore Contribution Agreement 1.1
>> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> >> ---
>> >>  Silicon/Socionext/SynQuacer/Library/NorFlashSynQuacerLib/NorFlashSynQuacer.c | 5 +++--
>> >>  1 file changed, 3 insertions(+), 2 deletions(-)
>> >>
>> >> diff --git a/Silicon/Socionext/SynQuacer/Library/NorFlashSynQuacerLib/NorFlashSynQuacer.c b/Silicon/Socionext/SynQuacer/Library/NorFlashSynQuacerLib/NorFlashSynQuacer.c
>> >> index 816d8ba33f8c..357082c3d903 100644
>> >> --- a/Silicon/Socionext/SynQuacer/Library/NorFlashSynQuacerLib/NorFlashSynQuacer.c
>> >> +++ b/Silicon/Socionext/SynQuacer/Library/NorFlashSynQuacerLib/NorFlashSynQuacer.c
>> >> @@ -23,8 +23,9 @@ STATIC NOR_FLASH_DESCRIPTION mNorFlashDevices[] = {
>> >>    {
>> >>      // UEFI code region
>> >>      SYNQUACER_SPI_NOR_BASE,                             // device base
>> >> -    FixedPcdGet64 (PcdFdBaseAddress),                   // region base
>> >> -    FixedPcdGet32 (PcdFdSize),                          // region size
>> >> +    SYNQUACER_SPI_NOR_BASE,                             // region base
>> >> +    FixedPcdGet32 (PcdFlashNvStorageVariableBase) -
>> >> +    SYNQUACER_SPI_NOR_BASE,                             // region size
>> >
>> > Could you define the size as a macro in Platform/MemoryMap.h?
>> >
>>
>> The memory map currently only contains constant macros. I can add this
>> expression
>>
>> FixedPcdGet32 (PcdFlashNvStorageVariableBase) - SYNQUACER_SPI_NOR_BASE
>>
>> somewhere as a #define but I would prefer it to be elsewhere, given
>> that it is not a SoC constant set in stone.
>
> I'm OK with that, but will just throw in the argument that the fact
> that it being a FixedPcdGet32 of PcdFlashNvStorageVariableBase is kind
> of set in stone. (And doesn't the Fixed bit make it constant?)
>

The point is more that MemoryMap.h describes properties of the SoC not
properties of our firmware implementation

But that also means that I should introduce a symbolic constant for
the start of the partition, e.g.,

#define FW_CODE_REGION_BASE    SYNQUACER_SPI_NOR_BASE
#define FW_CODE_REGION_SIZE    (FixedPcdGet32 (PcdFlashNvStorageVariableBase)
                               - SYNQUACER_SPI_NOR_BASE)

but I'd still prefer to keep it local to this file.

> Either way, my main interest is in making this struct definition not
> break my reading flow, so I'm perfectly happy with the #define
> elsewhere.
>
> /
>     Leif