stm32mp: cmd_stm32key: add subcommand close

The expected sequence to close the device

1/ Load key in DDR with any supported load command
2/ Update OTP with key: STM32MP> stm32key read <addr>

At this point the device is able to perform image authentication but
non-authenticated images can still be used and executed.
So it is the last moment to test boot with signed binary and
check that the ROM code accepts them.

3/ Close the device: only signed binary will be accepted !!
   STM32MP> stm32key close

Warning: Programming these OTP is an irreversible operation!
         This may brick your system if the HASH of key is invalid

This command should be deactivated by default in real product.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
This commit is contained in:
Patrick Delaunay 2021-06-28 14:56:03 +02:00
parent d3551b8eef
commit 80cfc6c692

View file

@ -210,10 +210,60 @@ static int do_stm32key_fuse(struct cmd_tbl *cmdtp, int flag, int argc, char *con
return CMD_RET_SUCCESS;
}
static int do_stm32key_close(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
bool yes, lock, closed;
struct udevice *dev;
u32 val;
int ret;
yes = false;
if (argc == 2) {
if (strcmp(argv[1], "-y"))
return CMD_RET_USAGE;
yes = true;
}
ret = read_hash_otp(!yes, &lock, &closed);
if (ret) {
if (ret == -ENOENT)
printf("Error: OTP not programmed!\n");
return CMD_RET_FAILURE;
}
if (closed) {
printf("Error: already closed!\n");
return CMD_RET_FAILURE;
}
if (!lock)
printf("Warning: OTP not locked!\n");
if (!yes && !confirm_prog())
return CMD_RET_FAILURE;
ret = get_misc_dev(&dev);
if (ret)
return CMD_RET_FAILURE;
val = STM32_OTP_CLOSE_MASK;
ret = misc_write(dev, STM32_BSEC_OTP(STM32_OTP_CLOSE_ID), &val, 4);
if (ret != 4) {
printf("Error: can't update OTP\n");
return CMD_RET_FAILURE;
}
printf("Device is closed !\n");
return CMD_RET_SUCCESS;
}
static char stm32key_help_text[] =
"read [<addr>]: Read the hash stored at addr in memory or in OTP\n"
"stm32key fuse [-y] <addr> : Fuse hash stored at addr in OTP\n";
"stm32key fuse [-y] <addr> : Fuse hash stored at addr in OTP\n"
"stm32key close [-y] : Close the device, the hash stored in OTP\n";
U_BOOT_CMD_WITH_SUBCMDS(stm32key, "Fuse ST Hash key", stm32key_help_text,
U_BOOT_SUBCMD_MKENT(read, 2, 0, do_stm32key_read),
U_BOOT_SUBCMD_MKENT(fuse, 3, 0, do_stm32key_fuse));
U_BOOT_SUBCMD_MKENT(fuse, 3, 0, do_stm32key_fuse),
U_BOOT_SUBCMD_MKENT(close, 2, 0, do_stm32key_close));