[U-Boot] [PATCH v2] cmd: mem: Add a command to fill the memory with random data

[Jean-Jacques Hiblot]

+Tom

On 02/07/2019 10:36, Jean-Jacques Hiblot wrote:
> This command fills the memory with data produced by rand().
> This command depends on CONFIG_LIB_RAND.
>
> Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>
> ---
> changes in v2:
> - Do not include the command if CONFIG_LIB_RAND is not set
> - make do_random() static
>
> cmd/Kconfig |  3 ++-
>   cmd/mem.c   | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 54 insertions(+), 1 deletion(-)
>
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index cda7931fe3..f9385fcc08 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -537,7 +537,7 @@ config CMD_MEMINFO
>   	  Display memory information.
>   
>   config CMD_MEMORY
> -	bool "md, mm, nm, mw, cp, cmp, base, loop"
> +	bool "md, mm, nm, mw, cp, cmp, base, loop, random"
>   	default y
>   	help
>   	  Memory commands.
> @@ -549,6 +549,7 @@ config CMD_MEMORY
>   	    cmp - memory compare
>   	    base - print or set address offset
>   	    loop - initialize loop on address range
> +	    random - fill memory with random data
>   
>   config CMD_MEMTEST
>   	bool "memtest"
> diff --git a/cmd/mem.c b/cmd/mem.c
> index 392ed1756b..e5af12db57 100644
> --- a/cmd/mem.c
> +++ b/cmd/mem.c
> @@ -1082,6 +1082,49 @@ static int do_mem_crc(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>   
>   #endif
>   
> +#ifdef CONFIG_LIB_RAND
> +static int do_random(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> +{
> +	unsigned long addr, len;
> +	unsigned long seed; // NOT INITIALIZED ON PURPOSE
> +	unsigned int *buf, *start;
> +	unsigned char *buf8;
> +	unsigned int i;
> +
> +	if (argc < 3 || argc > 4) {
> +		printf("usage: %s <addr> <len> [<seed>]\n", argv[0]);
> +		return 0;
> +	}
> +
> +	len = simple_strtoul(argv[2], NULL, 16);
> +	addr = simple_strtoul(argv[1], NULL, 16);
> +
> +	if (argc == 4) {
> +		seed = simple_strtoul(argv[3], NULL, 16);
> +		if (seed == 0) {
> +			printf("The seed cannot be 0. Using 0xDEADBEEF.\n");
> +			seed = 0xDEADBEEF;
> +		}
> +	} else {
> +		seed = get_timer(0) ^ rand();
> +	}
> +
> +	srand(seed);
> +	start = map_sysmem(addr, len);
> +	buf = start;
> +	for (i = 0; i < (len / 4); i++)
> +		*buf++ = rand();
> +
> +	buf8 = (unsigned char *)buf;
> +	for (i = 0; i < (len % 4); i++)
> +		*buf8++ = rand() & 0xFF;
> +
> +	unmap_sysmem(start);
> +	printf("%lu bytes filled with random data\n", len);
> +	return 1;
> +}
> +#endif
> +
>   /**************************************************/
>   U_BOOT_CMD(
>   	md,	3,	1,	do_mem_md,
> @@ -1250,3 +1293,12 @@ U_BOOT_CMD(
>   	""
>   );
>   #endif
> +
> +#ifdef CONFIG_LIB_RAND
> +U_BOOT_CMD(
> +	random,	4,	0,	do_random,
> +	"fill memory with random pattern",
> +	"<addr> <len> [<seed>]\n"
> +	"   - Fill 'len' bytes of memory starting at 'addr' with random data\n"
> +);
> +#endif