Re: [PATCH u-boot-mvebu 02/31] tools: kwbimage: Simplify aligning and calculating checksum

[Stefan Roese <sr@denx.de>]

On 08.07.21 19:30, Marek Behún wrote:
> From: Pali Rohár <pali@kernel.org>
> 
> The return value of kwbimage_generate() is used for aligning the data
> part of kwbimage. Use it for calculating proper 4 byte alignment as is
> required by BootROM and also use it for allocating additional 4 bytes
> for the 32-bit data checksum.
> 
> This simplifies the alignment code to be only at one place (in function
> kwbimage_generate) and also simplifies setting checksum as it can be
> directly updated in memory.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Reviewed-by: Marek Behún <marek.behun@nic.cz>

Reviewed-by: Stefan Roese <sr@denx.de>

Thanks,
Stefan

> ---
>   tools/kwbimage.c | 36 +++++++++++++++---------------------
>   1 file changed, 15 insertions(+), 21 deletions(-)
> 
> diff --git a/tools/kwbimage.c b/tools/kwbimage.c
> index 02fd0c949f..c775abf0e3 100644
> --- a/tools/kwbimage.c
> +++ b/tools/kwbimage.c
> @@ -891,7 +891,7 @@ static void *image_create_v0(size_t *imagesz, struct image_tool_params *params,
>   
>   	/* Fill in the main header */
>   	main_hdr->blocksize =
> -		cpu_to_le32(payloadsz + sizeof(uint32_t) - headersz);
> +		cpu_to_le32(payloadsz - headersz);
>   	main_hdr->srcaddr   = cpu_to_le32(headersz);
>   	main_hdr->ext       = has_ext;
>   	main_hdr->destaddr  = cpu_to_le32(params->addr);
> @@ -1249,7 +1249,7 @@ static void *image_create_v1(size_t *imagesz, struct image_tool_params *params,
>   
>   	/* Fill the main header */
>   	main_hdr->blocksize    =
> -		cpu_to_le32(payloadsz - headersz + sizeof(uint32_t));
> +		cpu_to_le32(payloadsz - headersz);
>   	main_hdr->headersz_lsb = cpu_to_le16(headersz & 0xFFFF);
>   	main_hdr->headersz_msb = (headersz & 0xFFFF0000) >> 16;
>   	main_hdr->destaddr     = cpu_to_le32(params->addr)
> @@ -1519,7 +1519,6 @@ static void kwbimage_set_header(void *ptr, struct stat *sbuf, int ifd,
>   	size_t headersz = 0;
>   	uint32_t checksum;
>   	int ret;
> -	int size;
>   
>   	fcfg = fopen(params->imagename, "r");
>   	if (!fcfg) {
> @@ -1547,9 +1546,6 @@ static void kwbimage_set_header(void *ptr, struct stat *sbuf, int ifd,
>   		exit(EXIT_FAILURE);
>   	}
>   
> -	/* The MVEBU BootROM does not allow non word aligned payloads */
> -	sbuf->st_size = ALIGN(sbuf->st_size, 4);
> -
>   	version = image_get_version();
>   	switch (version) {
>   		/*
> @@ -1580,16 +1576,10 @@ static void kwbimage_set_header(void *ptr, struct stat *sbuf, int ifd,
>   	free(image_cfg);
>   
>   	/* Build and add image checksum header */
> -	checksum =
> -		cpu_to_le32(image_checksum32((uint32_t *)ptr, sbuf->st_size));
> -	size = write(ifd, &checksum, sizeof(uint32_t));
> -	if (size != sizeof(uint32_t)) {
> -		fprintf(stderr, "Error:%s - Checksum write %d bytes %s\n",
> -			params->cmdname, size, params->imagefile);
> -		exit(EXIT_FAILURE);
> -	}
> -
> -	sbuf->st_size += sizeof(uint32_t);
> +	checksum = cpu_to_le32(image_checksum32((uint8_t *)ptr + headersz,
> +				sbuf->st_size - headersz - sizeof(uint32_t)));
> +	memcpy((uint8_t *)ptr + sbuf->st_size - sizeof(uint32_t), &checksum,
> +		sizeof(uint32_t));
>   
>   	/* Finally copy the header into the image area */
>   	memcpy(ptr, image, headersz);
> @@ -1650,6 +1640,7 @@ static int kwbimage_generate(struct image_tool_params *params,
>   			     struct image_type_params *tparams)
>   {
>   	FILE *fcfg;
> +	struct stat s;
>   	int alloc_len;
>   	int version;
>   	void *hdr;
> @@ -1662,6 +1653,12 @@ static int kwbimage_generate(struct image_tool_params *params,
>   		exit(EXIT_FAILURE);
>   	}
>   
> +	if (stat(params->datafile, &s)) {
> +		fprintf(stderr, "Could not stat data file %s: %s\n",
> +			params->datafile, strerror(errno));
> +		exit(EXIT_FAILURE);
> +	}
> +
>   	image_cfg = malloc(IMAGE_CFG_ELEMENT_MAX *
>   			   sizeof(struct image_cfg_element));
>   	if (!image_cfg) {
> @@ -1719,12 +1716,9 @@ static int kwbimage_generate(struct image_tool_params *params,
>   	/*
>   	 * The resulting image needs to be 4-byte aligned. At least
>   	 * the Marvell hdrparser tool complains if its unaligned.
> -	 * By returning 1 here in this function, called via
> -	 * tparams->vrec_header() in mkimage.c, mkimage will
> -	 * automatically pad the the resulting image to a 4-byte
> -	 * size if necessary.
> +	 * After the image data is stored 4-byte checksum.
>   	 */
> -	return 1;
> +	return 4 + (4 - s.st_size % 4) % 4;
>   }
>   
>   /*
> 


Viele Grüße,
Stefan

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