[PATCH 2/2] env: add CONFIG_ENV_SECT_SIZE_AUTO

[Rasmus Villemoes]

On 06/05/2020 10.59, Joakim Tjernlund wrote:
> On Wed, 2020-05-06 at 10:47 +0200, Rasmus Villemoes wrote:

>> At first, I wanted to allow setting CONFIG_ENV_SECT_SIZE to 0 to mean
>> "use the erase size the chip reports", but that config
>> option is used in a number of preprocessor conditionals, and shared
>> between ENV_IS_IN_FLASH and ENV_IS_IN_SPI_FLASH.
> 
> I see, It had been good if one could have used 0
> 
>>
>> So instead, introduce a new boolean config option, which for now can
>> only be used with ENV_IS_IN_SPI_FLASH. If left off, there's no change
>> in behaviour.
> 
> Please don't stop at just SPI Flash, we could use this for common NOR flashes too.

Certainly, but I don't have any such hardware, and the code also seems
to require a bit more work than the sf.c case due to the preprocessor
uses. It's quite possible that the

#if CONFIG_ENV_SECT_SIZE > CONFIG_ENV_SIZE
  foo; bar;
#endif

can be replaced by

u32 sect_size = CONFIG_ENV_SECT_SIZE;
if (IS_ENABLED(CONFIG_ENV_SECT_SIZE_AUTO))
  sect_size = [...however we want to get that info....]

if (sect_size > CONFIG_ENV_SIZE {
  foo; bar;
}

but then there's the uses of CONFIG_ENV_SECT_SIZE to initialize end_addr
and end_addr_new. So I think doing the flash.c part requires someone
with hardware access.

Rasmus