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c79e274c7c
Use a statically allocated buffer on stack instead of using malloc for reading the random bytes. Using a local array is faster than allocating heap memory on every initiation of the command. Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Reviewed-by: Simon Glass <sjg@chromium.org> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
70 lines
1.3 KiB
C
70 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* The 'rng' command prints bytes from the hardware random number generator.
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*
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* Copyright (c) 2019, Heinrich Schuchardt <xypron.glpk@gmx.de>
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*/
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#include <common.h>
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#include <command.h>
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#include <dm.h>
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#include <hexdump.h>
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#include <malloc.h>
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#include <rng.h>
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static int do_rng(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
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{
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size_t n;
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u8 buf[64];
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int devnum;
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struct udevice *dev;
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int ret = CMD_RET_SUCCESS;
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switch (argc) {
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case 1:
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devnum = 0;
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n = 0x40;
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break;
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case 2:
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devnum = hextoul(argv[1], NULL);
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n = 0x40;
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break;
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case 3:
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devnum = hextoul(argv[1], NULL);
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n = hextoul(argv[2], NULL);
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break;
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default:
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return CMD_RET_USAGE;
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}
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if (uclass_get_device_by_seq(UCLASS_RNG, devnum, &dev) || !dev) {
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printf("No RNG device\n");
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return CMD_RET_FAILURE;
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}
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if (!n)
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return 0;
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n = min(n, sizeof(buf));
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if (dm_rng_read(dev, buf, n)) {
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printf("Reading RNG failed\n");
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ret = CMD_RET_FAILURE;
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} else {
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print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buf, n);
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}
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return ret;
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}
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#ifdef CONFIG_SYS_LONGHELP
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static char rng_help_text[] =
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"[dev [n]]\n"
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" - print n random bytes(max 64) read from dev\n";
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#endif
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U_BOOT_CMD(
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rng, 3, 0, do_rng,
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"print bytes from the hardware random number generator",
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rng_help_text
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);
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