[PATCH v4 2/3] env: Access Environment in SPI flashes before relocation

[Tom Rini]

On Sat, Oct 31, 2020 at 12:51:27AM +0100, Michael Walle wrote:
> Hi Heiko, Hi Tom,
> 
> Am 2020-10-10 10:28, schrieb Heiko Schocher:
> > Enable the new Kconfig option ENV_SPI_EARLY if you want
> > to use Environment in SPI flash before relocation.
> > Call env_init() and than you can use env_get_f() for
> > accessing Environment variables.
> > 
> > Signed-off-by: Heiko Schocher <hs at denx.de>
> > ---
> > 
> > Changes in v4:
> > - rebased to current master 5dcf7cc590
> > 
> > Changes in v3:
> > - env_sf_init_early() always return 0 now. If we do not return
> >   0 in this function, env_set_inited() never get called,
> >   which has the consequence that env_load/save/erase never
> >   work, because they check if the init bit is set.
> > - add comment from Simon Glass
> >   - add missing function comments
> >   - use if(IS_ENABLED...)
> >   - drop extra brackets
> >   - let env_sf_init() decide, which function to call
> >     add comment that it is necessary to return env_sf_init()
> >     with 0.
> > 
> >  env/Kconfig |   8 +++++
> >  env/sf.c    | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++--
> >  2 files changed, 105 insertions(+), 3 deletions(-)
> > 
> > diff --git a/env/Kconfig b/env/Kconfig
> > index c6ba08878d..393b191a30 100644
> > --- a/env/Kconfig
> > +++ b/env/Kconfig
> > @@ -376,6 +376,14 @@ config ENV_SPI_MODE
> >  	  Value of the SPI work mode for environment.
> >  	  See include/spi.h for value.
> > 
> > +config ENV_SPI_EARLY
> > +	bool "Access Environment in SPI flashes before relocation"
> > +	depends on ENV_IS_IN_SPI_FLASH
> > +	help
> > +	  Enable this if you want to use Environment in SPI flash
> > +	  before relocation. Call env_init() and than you can use
> > +	  env_get_f() for accessing Environment variables.
> > +
> >  config ENV_IS_IN_UBI
> >  	bool "Environment in a UBI volume"
> >  	depends on !CHAIN_OF_TRUST
> > diff --git a/env/sf.c b/env/sf.c
> > index 937778aa37..2eb2de1a4e 100644
> > --- a/env/sf.c
> > +++ b/env/sf.c
> > @@ -287,7 +287,10 @@ __weak void *env_sf_get_env_addr(void)
> >  #endif
> > 
> >  #if defined(INITENV) && (CONFIG_ENV_ADDR != 0x0)
> > -static int env_sf_init(void)
> > +/*
> > + * check if Environment on CONFIG_ENV_ADDR is valid.
> > + */
> > +static int env_sf_init_addr(void)
> >  {
> >  	env_t *env_ptr = (env_t *)env_sf_get_env_addr();
> > 
> > @@ -303,12 +306,103 @@ static int env_sf_init(void)
> >  }
> >  #endif
> > 
> > +#if defined(CONFIG_ENV_SPI_EARLY)
> > +/*
> > + * early load environment from SPI flash (before relocation)
> > + * and check if it is valid.
> > + */
> > +static int env_sf_init_early(void)
> > +{
> > +	int ret;
> > +	int read1_fail;
> > +	int read2_fail;
> > +	int crc1_ok;
> > +	env_t *tmp_env2 = NULL;
> > +	env_t *tmp_env1;
> > +
> > +	/*
> > +	 * if malloc is not ready yet, we cannot use
> > +	 * this part yet.
> > +	 */
> > +	if (!gd->malloc_limit)
> > +		return -ENOENT;
> > +
> > +	tmp_env1 = (env_t *)memalign(ARCH_DMA_MINALIGN,
> > +			CONFIG_ENV_SIZE);
> > +	if (IS_ENABLED(CONFIG_SYS_REDUNDAND_ENVIRONMENT))
> > +		tmp_env2 = (env_t *)memalign(ARCH_DMA_MINALIGN,
> > +					     CONFIG_ENV_SIZE);
> > +
> > +	if (!tmp_env1 || !tmp_env2)
> > +		goto out;
> > +
> > +	ret = setup_flash_device();
> > +	if (ret)
> > +		goto out;
> > +
> > +	read1_fail = spi_flash_read(env_flash, CONFIG_ENV_OFFSET,
> > +				    CONFIG_ENV_SIZE, tmp_env1);
> > +
> > +	if (IS_ENABLED(CONFIG_SYS_REDUNDAND_ENVIRONMENT)) {
> > +		read2_fail = spi_flash_read(env_flash,
> > +					    CONFIG_ENV_OFFSET_REDUND,
> > +					    CONFIG_ENV_SIZE, tmp_env2);
> > +		ret = env_check_redund((char *)tmp_env1, read1_fail,
> > +				       (char *)tmp_env2, read2_fail);
> > +
> > +		if (ret == -EIO || ret == -ENOMSG)
> > +			goto err_read;
> > +
> > +		if (gd->env_valid == ENV_VALID)
> > +			gd->env_addr = (unsigned long)&tmp_env1->data;
> > +		else
> > +			gd->env_addr = (unsigned long)&tmp_env2->data;
> > +	} else {
> > +		if (read1_fail)
> > +			goto err_read;
> > +
> > +		crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
> > +				tmp_env1->crc;
> > +		if (!crc1_ok)
> > +			goto err_read;
> > +
> > +		/* if valid -> this is our env */
> > +		gd->env_valid = ENV_VALID;
> > +		gd->env_addr = (unsigned long)&tmp_env1->data;
> > +	}
> > +
> > +	return 0;
> > +err_read:
> > +	spi_flash_free(env_flash);
> > +	env_flash = NULL;
> > +	free(tmp_env1);
> > +	if (IS_ENABLED(CONFIG_SYS_REDUNDAND_ENVIRONMENT))
> > +		free(tmp_env2);
> > +out:
> > +	/* env is not valid. always return 0 */
> > +	gd->env_valid = ENV_INVALID;
> > +	return 0;
> > +}
> > +#endif
> > +
> > +static int env_sf_init(void)
> > +{
> > +#if defined(INITENV) && (CONFIG_ENV_ADDR != 0x0)
> > +	return env_sf_init_addr();
> > +#elif defined(CONFIG_ENV_SPI_EARLY)
> > +	return env_sf_init_early();
> > +#endif
> > +	/*
> > +	 * we must return with 0 if there is nothing done,
> > +	 * else env_set_inited() get not called in env_init()
> > +	 */
> > +	return 0;
> > +}
> > +
> >  U_BOOT_ENV_LOCATION(sf) = {
> >  	.location	= ENVL_SPI_FLASH,
> >  	ENV_NAME("SPIFlash")
> >  	.load		= env_sf_load,
> >  	.save		= CONFIG_IS_ENABLED(SAVEENV) ? ENV_SAVE_PTR(env_sf_save) :
> > NULL,
> > -#if defined(INITENV) && (CONFIG_ENV_ADDR != 0x0)
> >  	.init		= env_sf_init,
> > -#endif
> 
> This will break my board (the new kontron sl28). Before the
> change, the environment is loaded from SPI, after this patch
> the environment won't be loaded anymore. If I delete the
> .init callback, the behavior is the same as before.
> 
> The problem here is that returning 0 in env_sf_init() is not
> enough because if the .init callback is not set, env_init() will
> have ret defaulting to -ENOENT and in this case will load the
> default environment and setting env_valid to ENV_VALID. I didn't
> follow the whole call chain then. But this will then eventually
> lead to loading the actual environment in a later stage.

Ugh.  The games we play in the env area really just need to be
rewritten.  So at this point I've merged the series, should I revert or
do you see an easy fix for your platform?  Thanks!

-- 
Tom
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