[U-Boot] [PATCH 1/9] lib: Add CRC32-C

[Łukasz Majewski]

Hi Marek,

> This is needed for BTRFS.
> 
> Signed-off-by: Marek Behun <marek.behun at nic.cz>
> 
>   create mode 100644 lib/crc32c.c

Excuse me my ignorance, but in u-boot we already have:
./lib/crc32.c

is the crc32c algorithm a different one from venerable crc32?


> 
> diff --git a/include/u-boot/crc.h b/include/u-boot/crc.h
> index 6764d58bab..6d08f5df98 100644
> --- a/include/u-boot/crc.h
> +++ b/include/u-boot/crc.h
> @@ -28,4 +28,8 @@ uint32_t crc32_no_comp (uint32_t, const unsigned char *, uint);
>   void crc32_wd_buf(const unsigned char *input, uint ilen,
>   		    unsigned char *output, uint chunk_sz);
>   
> +/* lib/crc32c.c */
> +void crc32c_init(uint32_t *, uint32_t);
> +uint32_t crc32c_cal(uint32_t, const char *, int, uint32_t *);
> +
>   #endif /* _UBOOT_CRC_H */
> diff --git a/lib/Kconfig b/lib/Kconfig
> index fe337acaeb..29e55dbe1d 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -146,6 +146,9 @@ config SHA_PROG_HW_ACCEL
>   config MD5
>   	bool
>   
> +config CRC32C
> +	bool
> +
>   endmenu
>   
>   menu "Compression Support"
> diff --git a/lib/Makefile b/lib/Makefile
> index 2eef1eb80e..a58ce0f815 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -67,6 +67,7 @@ obj-y += display_options.o
>   CFLAGS_display_options.o := $(if $(BUILD_TAG),-DBUILD_TAG='"$(BUILD_TAG)"')
>   obj-$(CONFIG_BCH) += bch.o
>   obj-y += crc32.o
> +obj-$(CONFIG_CRC32C) += crc32c.o
>   obj-y += ctype.o
>   obj-y += div64.o
>   obj-y += hang.o
> diff --git a/lib/crc32c.c b/lib/crc32c.c
> new file mode 100644
> index 0000000000..322c08ff5d
> --- /dev/null
> +++ b/lib/crc32c.c
> @@ -0,0 +1,38 @@
> +/*
> + * Copied from Linux kernel crypto/crc32c.c
> + * Copyright (c) 2004 Cisco Systems, Inc.
> + * Copyright (c) 2008 Herbert Xu <herbert at gondor.apana.org.au>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the Free
> + * Software Foundation; either version 2 of the License, or (at your option)
> + * any later version.
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <compiler.h>
> +
> +uint32_t crc32c_cal(uint32_t crc, const char *data, int length,
> +		    uint32_t *crc32c_table)
> +{
> +	while (length--)
> +		crc = crc32c_table[(u8)(crc ^ *data++)] ^ (crc >> 8);
> +
> +	return crc;
> +}
> +
> +void crc32c_init(uint32_t *crc32c_table, uint32_t pol)
> +{
> +	int i, j;
> +	uint32_t v;
> +	const uint32_t poly = pol; /* Bit-reflected CRC32C polynomial */
> +
> +	for (i = 0; i < 256; i++) {
> +		v = i;
> +		for (j = 0; j < 8; j++)
> +			v = (v >> 1) ^ ((v & 1) ? poly : 0);
> +
> +		crc32c_table[i] = v;
> +	}
> +}
> 


-- 
Best regards,

Lukasz Majewski

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