diff mbox series

[v2,1/2] env: add SAVEENV as an alias of the CMD_SAVEENV symbol

Message ID 20200326230200.12617-2-rasmus.villemoes@prevas.dk
State Accepted
Commit 1d0adee45cc2d3257c926d6022bf1922805b928e
Headers show
Series allow CONFIG_SPL_SAVEENV to work with ENV_IS_IN_SPI_FLASH | expand

Commit Message

Rasmus Villemoes March 26, 2020, 11:01 p.m. UTC
Currently, quite a few storage drivers currently do not honour
SPL_SAVEENV. That is, whether or not one enables CONFIG_SPL_SAVEENV,
the backend drivers do not provide the .save method. Witness

env/fat.c:#ifdef CONFIG_SPL_BUILD
...
env/fat.c-#else
env/fat.c-# define LOADENV
env/fat.c:# if defined(CONFIG_CMD_SAVEENV)
env/fat.c:#  define CMD_SAVEENV
env/fat.c-# endif
env/fat.c-#endif
env/fat.c-
env/fat.c:#ifdef CMD_SAVEENV
env/fat.c-static int env_fat_save(void)

env/flash.c:#ifndef CONFIG_SPL_BUILD
env/flash.c:# if defined(CONFIG_CMD_SAVEENV) && defined(CONFIG_CMD_FLASH)
env/flash.c:#  define CMD_SAVEENV
...
env/flash.c:#ifdef CMD_SAVEENV
env/flash.c-static int env_flash_save(void)

env/mmc.c:#if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_SPL_BUILD)
env/mmc.c-static inline int write_env(struct mmc *mmc, unsigned long size,

env/nand.c:#if defined(CONFIG_CMD_SAVEENV) && defined(CONFIG_CMD_NAND) && \
env/nand.c:             !defined(CONFIG_SPL_BUILD)
env/nand.c:#define CMD_SAVEENV
...
env/nand.c:#ifdef CMD_SAVEENV
env/nand.c-/*
env/nand.c- * The legacy NAND code saved the environment in the first NAND device i.e.,
env/nand.c- * nand_dev_desc + 0. This is also the behaviour using the new NAND code.
env/nand.c- */
env/nand.c-static int writeenv(size_t offset, u_char *buf)

env/sf.c:#ifndef CONFIG_SPL_BUILD
env/sf.c:#define CMD_SAVEENV
env/sf.c-#define INITENV
env/sf.c-#endif
...
env/sf.c:#ifdef CMD_SAVEENV
env/sf.c-static int env_sf_save(void)

In all these cases, the mere presence of CONFIG_SPL_BUILD means the
save method does not get built.

Now, it is currently a bit awkward to write a proper test for whether
saving the environment is enabled in the current context; something
like

#if (!defined(CONFIG_SPL_BUILD) && defined(CONFIG_CMD_SAVEENV)) || \
    (defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_SAVEENV))

But we already have a rather elegant mechanism that implicitly does
the CONFIG_SPL_BUILD tests, namely CONFIG_IS_ENABLED(). Using that
requires that the controlling config symbols follow a strict pattern:
FOO for U-Boot proper, SPL_FOO for SPL.

This patch introduces CONFIG_SAVEENV as an alias for
CONFIG_CMD_SAVEENV. That way, the above can simply be written

#if CONFIG_IS_ENABLED(SAVEENV)

and moreover, CONFIG_IS_ENABLED(SAVEENV) can also be used in C code,
avoiding ifdeffery and providing more compile testing.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes at prevas.dk>
---
v2: Expand commit message, explain why one needs a new config symbol
in order to use CONFIG_IS_ENABLED, and demonstrate how many of the
storage drivers don't compile their .save method when
CONFIG_SPL_BUILD. The patch itself is the same.

 env/Kconfig | 3 +++
 1 file changed, 3 insertions(+)

Comments

Tom Rini May 8, 2020, 10:59 p.m. UTC | #1
On Fri, Mar 27, 2020 at 12:01:59AM +0100, Rasmus Villemoes wrote:

> Currently, quite a few storage drivers currently do not honour
> SPL_SAVEENV. That is, whether or not one enables CONFIG_SPL_SAVEENV,
> the backend drivers do not provide the .save method. Witness
> 
> env/fat.c:#ifdef CONFIG_SPL_BUILD
> ...
> env/fat.c-#else
> env/fat.c-# define LOADENV
> env/fat.c:# if defined(CONFIG_CMD_SAVEENV)
> env/fat.c:#  define CMD_SAVEENV
> env/fat.c-# endif
> env/fat.c-#endif
> env/fat.c-
> env/fat.c:#ifdef CMD_SAVEENV
> env/fat.c-static int env_fat_save(void)
> 
> env/flash.c:#ifndef CONFIG_SPL_BUILD
> env/flash.c:# if defined(CONFIG_CMD_SAVEENV) && defined(CONFIG_CMD_FLASH)
> env/flash.c:#  define CMD_SAVEENV
> ...
> env/flash.c:#ifdef CMD_SAVEENV
> env/flash.c-static int env_flash_save(void)
> 
> env/mmc.c:#if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_SPL_BUILD)
> env/mmc.c-static inline int write_env(struct mmc *mmc, unsigned long size,
> 
> env/nand.c:#if defined(CONFIG_CMD_SAVEENV) && defined(CONFIG_CMD_NAND) && \
> env/nand.c:             !defined(CONFIG_SPL_BUILD)
> env/nand.c:#define CMD_SAVEENV
> ...
> env/nand.c:#ifdef CMD_SAVEENV
> env/nand.c-/*
> env/nand.c- * The legacy NAND code saved the environment in the first NAND device i.e.,
> env/nand.c- * nand_dev_desc + 0. This is also the behaviour using the new NAND code.
> env/nand.c- */
> env/nand.c-static int writeenv(size_t offset, u_char *buf)
> 
> env/sf.c:#ifndef CONFIG_SPL_BUILD
> env/sf.c:#define CMD_SAVEENV
> env/sf.c-#define INITENV
> env/sf.c-#endif
> ...
> env/sf.c:#ifdef CMD_SAVEENV
> env/sf.c-static int env_sf_save(void)
> 
> In all these cases, the mere presence of CONFIG_SPL_BUILD means the
> save method does not get built.
> 
> Now, it is currently a bit awkward to write a proper test for whether
> saving the environment is enabled in the current context; something
> like
> 
> #if (!defined(CONFIG_SPL_BUILD) && defined(CONFIG_CMD_SAVEENV)) || \
>     (defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_SAVEENV))
> 
> But we already have a rather elegant mechanism that implicitly does
> the CONFIG_SPL_BUILD tests, namely CONFIG_IS_ENABLED(). Using that
> requires that the controlling config symbols follow a strict pattern:
> FOO for U-Boot proper, SPL_FOO for SPL.
> 
> This patch introduces CONFIG_SAVEENV as an alias for
> CONFIG_CMD_SAVEENV. That way, the above can simply be written
> 
> #if CONFIG_IS_ENABLED(SAVEENV)
> 
> and moreover, CONFIG_IS_ENABLED(SAVEENV) can also be used in C code,
> avoiding ifdeffery and providing more compile testing.
> 
> Signed-off-by: Rasmus Villemoes <rasmus.villemoes at prevas.dk>

Applied to u-boot/master, thanks!
diff mbox series

Patch

diff --git a/env/Kconfig b/env/Kconfig
index 0d6f559b39..969308fe6c 100644
--- a/env/Kconfig
+++ b/env/Kconfig
@@ -3,6 +3,9 @@  menu "Environment"
 config ENV_SUPPORT
 	def_bool y
 
+config SAVEENV
+	def_bool y if CMD_SAVEENV
+
 config ENV_IS_NOWHERE
 	bool "Environment is not stored"
 	default y if !ENV_IS_IN_EEPROM && !ENV_IS_IN_EXT4 && \