[PATCH] arm: stm32mp1: force boot_device variable for invalid TAMP register value

[Patrick Delaunay]

When the TAMP register 20 have an invalid value (0x0 for example after
TAMPER error) the "boot_device" U-Boot env variable have no value and
no error is displayed in U-Boot log.

The STM32MP boot command bootcmd_stm32mp failed with strange trace:
  "Boot over !"

and the next command in bootcmd_stm32mp failed with few indication:
  if test ${boot_device} = serial || test ${boot_device} = usb;
	then stm32prog ${boot_device} ${boot_instance};

As it is difficult to investigate, the current patch avoids this issue:
- change the debug message to error: "unexpected boot mode" is displayed
- display trace "Boot over invalid!" in bootcmd_stm32mp
- execute "run distro_bootcmd" to try all the possible target

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

 arch/arm/mach-stm32mp/cpu.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-stm32mp/cpu.c b/arch/arm/mach-stm32mp/cpu.c
index 592bfd413d..5ea1ddc497 100644
--- a/arch/arm/mach-stm32mp/cpu.c
+++ b/arch/arm/mach-stm32mp/cpu.c
@@ -542,7 +542,9 @@ static void setup_boot_mode(void)
 		env_set("boot_instance", "0");
 		break;
 	default:
-		log_debug("unexpected boot mode = %x\n", boot_mode);
+		env_set("boot_device", "invalid");
+		env_set("boot_instance", "");
+		log_err("unexpected boot mode = %x\n", boot_mode);
 		break;
 	}
 
-- 
2.25.1