arch/arm/mach-stm32mp/cmd_stm32key.c

   1 // SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
   2 /*
   3  * Copyright (C) 2019, STMicroelectronics - All Rights Reserved
   4  */
   5
   6 #include <common.h>
   7 #include <command.h>
   8 #include <console.h>
   9 #include <log.h>
  10 #include <misc.h>
  11 #include <dm/device.h>
  12 #include <dm/uclass.h>
  13
  14 #define STM32_OTP_HASH_KEY_START 24
  15 #define STM32_OTP_HASH_KEY_SIZE 8
  16
  17 static void read_hash_value(u32 addr)
  18 {
  19         int i;
  20
  21         for (i = 0; i < STM32_OTP_HASH_KEY_SIZE; i++) {
  22                 printf("OTP value %i: %x\n", STM32_OTP_HASH_KEY_START + i,
  23                        __be32_to_cpu(*(u32 *)addr));
  24                 addr += 4;
  25         }
  26 }
  27
  28 static int fuse_hash_value(u32 addr, bool print)
  29 {
  30         struct udevice *dev;
  31         u32 word, val;
  32         int i, ret;
  33
  34         ret = uclass_get_device_by_driver(UCLASS_MISC,
  35                                           DM_DRIVER_GET(stm32mp_bsec),
  36                                           &dev);
  37         if (ret) {
  38                 log_err("Can't find stm32mp_bsec driver\n");
  39                 return ret;
  40         }
  41
  42         for (i = 0, word = STM32_OTP_HASH_KEY_START;
  43              i < STM32_OTP_HASH_KEY_SIZE;
  44              i++, word++, addr += 4) {
  45                 val = __be32_to_cpu(*(u32 *)addr);
  46                 if (print)
  47                         printf("Fuse OTP %i : %x\n", word, val);
  48
  49                 ret = misc_write(dev, STM32_BSEC_OTP(word), &val, 4);
  50                 if (ret != 4) {
  51                         log_err("Fuse OTP %i failed\n", word);
  52                         return ret;
  53                 }
  54                 /* on success, lock the OTP for HASH key */
  55                 val = 1;
  56                 ret = misc_write(dev, STM32_BSEC_LOCK(word), &val, 4);
  57                 if (ret != 4) {
  58                         log_err("Lock OTP %i failed\n", word);
  59                         return ret;
  60                 }
  61         }
  62
  63         return 0;
  64 }
  65
  66 static int confirm_prog(void)
  67 {
  68         puts("Warning: Programming fuses is an irreversible operation!\n"
  69                         "         This may brick your system.\n"
  70                         "         Use this command only if you are sure of what you are doing!\n"
  71                         "\nReally perform this fuse programming? <y/N>\n");
  72
  73         if (confirm_yesno())
  74                 return 1;
  75
  76         puts("Fuse programming aborted\n");
  77         return 0;
  78 }
  79
  80 static int do_stm32key_read(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
  81 {
  82         u32 addr;
  83
  84         if (argc == 1)
  85                 return CMD_RET_USAGE;
  86
  87         addr = simple_strtoul(argv[1], NULL, 16);
  88         if (!addr)
  89                 return CMD_RET_USAGE;
  90
  91         read_hash_value(addr);
  92
  93         return CMD_RET_SUCCESS;
  94 }
  95
  96 static int do_stm32key_fuse(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
  97 {
  98         u32 addr;
  99         bool yes = false;
 100
 101         if (argc < 2)
 102                 return CMD_RET_USAGE;
 103
 104         if (argc == 3) {
 105                 if (strcmp(argv[1], "-y"))
 106                         return CMD_RET_USAGE;
 107                 yes = true;
 108         }
 109
 110         addr = simple_strtoul(argv[argc - 1], NULL, 16);
 111         if (!addr)
 112                 return CMD_RET_USAGE;
 113
 114         if (!yes && !confirm_prog())
 115                 return CMD_RET_FAILURE;
 116
 117         if (fuse_hash_value(addr, !yes))
 118                 return CMD_RET_FAILURE;
 119
 120         printf("Hash key updated !\n");
 121
 122         return CMD_RET_SUCCESS;
 123 }
 124
 125 static char stm32key_help_text[] =
 126         "read <addr>: Read the hash stored at addr in memory\n"
 127         "stm32key fuse [-y] <addr> : Fuse hash stored at addr in OTP\n";
 128
 129 U_BOOT_CMD_WITH_SUBCMDS(stm32key, "Fuse ST Hash key", stm32key_help_text,
 130         U_BOOT_SUBCMD_MKENT(read, 2, 0, do_stm32key_read),
 131         U_BOOT_SUBCMD_MKENT(fuse, 3, 0, do_stm32key_fuse));