|
@@ -0,0 +1,81 @@
|
|
|
+// SPDX-License-Identifier: GPL-2.0+
|
|
|
+/*
|
|
|
+ * The 'kaslrseed' command takes bytes from the hardware random number
|
|
|
+ * generator and uses them to set the kaslr-seed value in the chosen node.
|
|
|
+ *
|
|
|
+ * Copyright (c) 2021, Chris Morgan <macromorgan@hotmail.com>
|
|
|
+ */
|
|
|
+
|
|
|
+#include <common.h>
|
|
|
+#include <command.h>
|
|
|
+#include <dm.h>
|
|
|
+#include <hexdump.h>
|
|
|
+#include <malloc.h>
|
|
|
+#include <rng.h>
|
|
|
+#include <fdt_support.h>
|
|
|
+
|
|
|
+static int do_kaslr_seed(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
|
|
|
+{
|
|
|
+ size_t n = 0x8;
|
|
|
+ struct udevice *dev;
|
|
|
+ u64 *buf;
|
|
|
+ int nodeoffset;
|
|
|
+ int ret = CMD_RET_SUCCESS;
|
|
|
+
|
|
|
+ if (uclass_get_device(UCLASS_RNG, 0, &dev) || !dev) {
|
|
|
+ printf("No RNG device\n");
|
|
|
+ return CMD_RET_FAILURE;
|
|
|
+ }
|
|
|
+
|
|
|
+ buf = malloc(n);
|
|
|
+ if (!buf) {
|
|
|
+ printf("Out of memory\n");
|
|
|
+ return CMD_RET_FAILURE;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (dm_rng_read(dev, buf, n)) {
|
|
|
+ printf("Reading RNG failed\n");
|
|
|
+ return CMD_RET_FAILURE;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (!working_fdt) {
|
|
|
+ printf("No FDT memory address configured. Please configure\n"
|
|
|
+ "the FDT address via \"fdt addr <address>\" command.\n"
|
|
|
+ "Aborting!\n");
|
|
|
+ return CMD_RET_FAILURE;
|
|
|
+ }
|
|
|
+
|
|
|
+ ret = fdt_check_header(working_fdt);
|
|
|
+ if (ret < 0) {
|
|
|
+ printf("fdt_chosen: %s\n", fdt_strerror(ret));
|
|
|
+ return CMD_RET_FAILURE;
|
|
|
+ }
|
|
|
+
|
|
|
+ nodeoffset = fdt_find_or_add_subnode(working_fdt, 0, "chosen");
|
|
|
+ if (nodeoffset < 0) {
|
|
|
+ printf("Reading chosen node failed\n");
|
|
|
+ return CMD_RET_FAILURE;
|
|
|
+ }
|
|
|
+
|
|
|
+ ret = fdt_setprop(working_fdt, nodeoffset, "kaslr-seed", buf, sizeof(buf));
|
|
|
+ if (ret < 0) {
|
|
|
+ printf("Unable to set kaslr-seed on chosen node: %s\n", fdt_strerror(ret));
|
|
|
+ return CMD_RET_FAILURE;
|
|
|
+ }
|
|
|
+
|
|
|
+ free(buf);
|
|
|
+
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+#ifdef CONFIG_SYS_LONGHELP
|
|
|
+static char kaslrseed_help_text[] =
|
|
|
+ "[n]\n"
|
|
|
+ " - append random bytes to chosen kaslr-seed node\n";
|
|
|
+#endif
|
|
|
+
|
|
|
+U_BOOT_CMD(
|
|
|
+ kaslrseed, 1, 0, do_kaslr_seed,
|
|
|
+ "feed bytes from the hardware random number generator to the kaslr-seed",
|
|
|
+ kaslrseed_help_text
|
|
|
+);
|