stm32mp1: key: add stm32key command

Add dedicated command to register in fuse a public hash
key provided by keygen tool.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

arch/arm/mach-stm32mp/Kconfig

@@ -90,6 +90,14 @@ config STM32_ETZPC
 	help
 	  Say y to enable STM32 Extended TrustZone Protection
 
+config CMD_STM32KEY
+	bool "command stm32key to fuse public key hash"
+	default y
+	depends on CMD_FUSE
+	help
+		fuse public key hash in corresponding fuse used to authenticate
+		binary.
+
 config BOOTSTAGE_STASH_ADDR
 	default 0xC3000000
 

arch/arm/mach-stm32mp/Makefile

@@ -11,6 +11,7 @@ ifdef CONFIG_SPL_BUILD
 obj-y += spl.o
 else
 obj-y += bsec.o
+obj-$(CONFIG_CMD_STM32KEY) += cmd_stm32key.o
 ifndef CONFIG_STM32MP1_TRUSTED
 obj-$(CONFIG_SYSRESET) += cmd_poweroff.o
 endif

arch/arm/mach-stm32mp/cmd_stm32key.c

@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+/*
+ * Copyright (C) 2019, STMicroelectronics - All Rights Reserved
+ */
+
+#include <common.h>
+#include <command.h>
+#include <console.h>
+#include <misc.h>
+#include <dm/device.h>
+#include <dm/uclass.h>
+
+#define STM32_OTP_HASH_KEY_START 24
+#define STM32_OTP_HASH_KEY_SIZE 8
+
+static void read_hash_value(u32 addr)
+{
+	int i;
+
+	for (i = 0; i < STM32_OTP_HASH_KEY_SIZE; i++) {
+		printf("OTP value %i: %x\n", STM32_OTP_HASH_KEY_START + i,
+		       __be32_to_cpu(*(u32 *)addr));
+		addr += 4;
+	}
+}
+
+static void fuse_hash_value(u32 addr, bool print)
+{
+	struct udevice *dev;
+	u32 word, val;
+	int i, ret;
+
+	ret = uclass_get_device_by_driver(UCLASS_MISC,
+					  DM_GET_DRIVER(stm32mp_bsec),
+					  &dev);
+	if (ret) {
+		pr_err("Can't find stm32mp_bsec driver\n");
+		return;
+	}
+
+	for (i = 0; i < STM32_OTP_HASH_KEY_SIZE; i++) {
+		if (print)
+			printf("Fuse OTP %i : %x\n",
+			       STM32_OTP_HASH_KEY_START + i,
+			       __be32_to_cpu(*(u32 *)addr));
+
+		word = STM32_OTP_HASH_KEY_START + i;
+		val = __be32_to_cpu(*(u32 *)addr);
+		misc_write(dev, STM32_BSEC_OTP(word), &val, 4);
+
+		addr += 4;
+	}
+}
+
+static int confirm_prog(void)
+{
+	puts("Warning: Programming fuses is an irreversible operation!\n"
+			"         This may brick your system.\n"
+			"         Use this command only if you are sure of what you are doing!\n"
+			"\nReally perform this fuse programming? <y/N>\n");
+
+	if (confirm_yesno())
+		return 1;
+
+	puts("Fuse programming aborted\n");
+	return 0;
+}
+
+static int do_stm32key(cmd_tbl_t *cmdtp, int flag, int argc,
+		       char * const argv[])
+{
+	u32 addr;
+	const char *op = argc >= 2 ? argv[1] : NULL;
+	int confirmed = argc > 3 && !strcmp(argv[2], "-y");
+
+	argc -= 2 + confirmed;
+	argv += 2 + confirmed;
+
+	if (argc < 1)
+		return CMD_RET_USAGE;
+
+	addr = simple_strtoul(argv[0], NULL, 16);
+	if (!addr)
+		return CMD_RET_USAGE;
+
+	if (!strcmp(op, "read"))
+		read_hash_value(addr);
+
+	if (!strcmp(op, "fuse")) {
+		if (!confirmed && !confirm_prog())
+			return CMD_RET_FAILURE;
+		fuse_hash_value(addr, !confirmed);
+	}
+
+	return CMD_RET_SUCCESS;
+}
+
+U_BOOT_CMD(stm32key, 4, 1, do_stm32key,
+	   "Fuse ST Hash key",
+	   "read <addr>: Read the hash store at addr in memory\n"
+	   "stm32key fuse [-y] <addr> : Fuse hash store at addr in otp\n");