Re: [PATCH] crypto: crc32: make crc32 available in PBL

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 29.08.23 11:28, Johannes Zink wrote:
> crc32 may be required in PBL for checking data integrity. Add
> CONFIG_CRC32_EARLY to kconfig which allows adding crc32 also in the PBL.
> 
> As the PBL has no dynamic allocation, do not use dynamic CRC table
> generation when CRC32 is added in PBL.
> 
> Signed-off-by: Johannes Zink <j.zink@pengutronix.de>
> ---
> To: Barebox Mailing List <barebox@lists.infradead.org>
> Cc: Johannes Zink <j.zink@pengutronix.de>
> Cc: patchwork-jzi@pengutronix.de
> ---
>  crypto/Kconfig  | 3 +++
>  crypto/Makefile | 1 +
>  crypto/crc32.c  | 6 +++---
>  3 files changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/crypto/Kconfig b/crypto/Kconfig
> index 04e5ef43705b..6e18b5868061 100644
> --- a/crypto/Kconfig
> +++ b/crypto/Kconfig
> @@ -5,6 +5,9 @@ menu "Crypto support"
>  config CRC32
>  	bool
>  
> +config CRC32_EARLY
> +	bool
> +
>  config CRC_ITU_T
>  	bool
>  
> diff --git a/crypto/Makefile b/crypto/Makefile
> index 22035d4f69ee..24e1f3d91797 100644
> --- a/crypto/Makefile
> +++ b/crypto/Makefile
> @@ -11,6 +11,7 @@ obj-$(CONFIG_DIGEST_SHA1_GENERIC)	+= sha1.o
>  obj-$(CONFIG_DIGEST_SHA224_GENERIC)	+= sha2.o
>  obj-$(CONFIG_DIGEST_SHA256_GENERIC)	+= sha2.o
>  pbl-y					+= sha2.o digest.o
> +lwl-$(CONFIG_CRC32_EARLY)		+= crc32.o

pbl-obj- is the correct prefix. lwl- means pbl- if we have PBL
support at all and obj- otherwise (for legacy systems without PBL),
while pbl-obj- is equivalent to duplicating the line once with pbl-
and once with obj-

>  obj-$(CONFIG_DIGEST_SHA384_GENERIC)	+= sha4.o
>  obj-$(CONFIG_DIGEST_SHA512_GENERIC)	+= sha4.o
>  obj-y	+= memneq.o
> diff --git a/crypto/crc32.c b/crypto/crc32.c
> index 95cb2212db2b..284d39351682 100644
> --- a/crypto/crc32.c
> +++ b/crypto/crc32.c
> @@ -22,7 +22,7 @@
>  #define STATIC static inline
>  #endif
>  
> -#ifdef CONFIG_DYNAMIC_CRC_TABLE
> +#if defined(CONFIG_DYNAMIC_CRC_TABLE) && !defined(__PBL__)

You could also replace the dynamic allocation with a static array initialized
to zero. That way you can have a dynamic crc table even in PBL without affecting
image size as the BSS is not part of the image.

>  
>  static uint32_t *crc_table;
>  
> @@ -145,7 +145,7 @@ STATIC uint32_t crc32(uint32_t crc, const void *_buf, unsigned int len)
>  {
>      const unsigned char *buf = _buf;
>  
> -#ifdef CONFIG_DYNAMIC_CRC_TABLE
> +#if defined(CONFIG_DYNAMIC_CRC_TABLE) && !defined(__PBL__)
>  	if (!crc_table)
>  		make_crc_table();
>  #endif
> @@ -171,7 +171,7 @@ STATIC uint32_t crc32_no_comp(uint32_t crc, const void *_buf, unsigned int len)
>  {
>     const unsigned char *buf = _buf;
>  
> -#ifdef CONFIG_DYNAMIC_CRC_TABLE
> +#if defined(CONFIG_DYNAMIC_CRC_TABLE) && !defined(__PBL__)
>  	if (!crc_table)
>  		make_crc_table();
>  #endif
> 
> ---
> base-commit: bef38b18eeb5d2f1fac334fb8b831e47261e099c
> change-id: 20230829-crc32_in_pbl-4d824629d4e2
> 
> Best regards,

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