arm: mvebu: turris_omnia: support invoking rescue boot from console

Make it possible to invoke rescue boot from U-Boot console, without
having to press the factory reset button. This is needed when accessing
the device remotely, for example.

Achieve this by putting rescue command into `bootcmd_rescue` default
environment variable and setting some distroboot environment variables
to their default values when the factory button is pressed.

Rescue boot from console can be invoked by running
  run bootcmd_rescue

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>

2 files changed, 52 insertions, 24 deletions

diff --git a/board/CZ.NIC/turris_omnia/turris_omnia.c b/board/CZ.NIC/turris_omnia/turris_omnia.c
index d3de8004eb..ade923f599 100644
--- a/board/CZ.NIC/turris_omnia/turris_omnia.c
+++ b/board/CZ.NIC/turris_omnia/turris_omnia.c
@@ -337,29 +337,6 @@ static int set_regdomain(void)
 	return env_set("regdomain", rd);
 }
 
-/*
- * default factory reset bootcommand on Omnia first sets all the front LEDs
- * to green and then tries to load the rescue image from SPI flash memory and
- * boot it
- */
-#define OMNIA_FACTORY_RESET_BOOTCMD \
-	"i2c dev 2; " \
-	"i2c mw 0x2a.1 0x3 0x1c 1; " \
-	"i2c mw 0x2a.1 0x4 0x1c 1; " \
-	"mw.l 0x01000000 0x00ff000c; " \
-	"i2c write 0x01000000 0x2a.1 0x5 4 -s; " \
-	"setenv bootargs \"earlyprintk console=ttyS0,115200" \
-		" omniarescue=$omnia_reset rescue_mode=$omnia_reset\"; " \
-	"sf probe; " \
-	"sf read 0x1000000 0x100000 0x700000; " \
-	"lzmadec 0x1000000 0x1700000; " \
-	"if gpio input gpio@71_4; then " \
-		"bootm 0x1700000#sfp; " \
-	"else " \
-		"bootm 0x1700000; " \
-	"fi; " \
-	"bootz 0x1000000"
-
 static void handle_reset_button(void)
 {
 	int ret;
@@ -375,8 +352,36 @@ static void handle_reset_button(void)
 	env_set_ulong("omnia_reset", reset_status);
 
 	if (reset_status) {
+		const char * const vars[3] = {
+			"bootcmd",
+			"bootcmd_rescue",
+			"distro_bootcmd",
+		};
+
+		/*
+		 * Set the above envs to their default values, in case the user
+		 * managed to break them.
+		 */
+		env_set_default_vars(3, (char * const *)vars, 0);
+
+		/* Ensure bootcmd_rescue is used by distroboot */
+		env_set("boot_targets", "rescue");
+
 		printf("RESET button was pressed, overwriting bootcmd!\n");
-		env_set("bootcmd", OMNIA_FACTORY_RESET_BOOTCMD);
+	} else {
+		/*
+		 * In case the user somehow managed to save environment with
+		 * boot_targets=rescue, reset boot_targets to default value.
+		 * This could happen in subsequent commands if bootcmd_rescue
+		 * failed.
+		 */
+		if (!strcmp(env_get("boot_targets"), "rescue")) {
+			const char * const vars[1] = {
+				"boot_targets",
+			};
+
+			env_set_default_vars(1, (char * const *)vars, 0);
+		}
 	}
 }
 #endif
diff --git a/include/configs/turris_omnia.h b/include/configs/turris_omnia.h
index 0b55c14d8b..7da18f97db 100644
--- a/include/configs/turris_omnia.h
+++ b/include/configs/turris_omnia.h
@@ -108,12 +108,35 @@
 
 #include <config_distro_bootcmd.h>
 
+/*
+ * The factory reset bootcommand on Omnia first sets all the front LEDs to green
+ * and then tries to load the rescue image from SPI flash memory and boot it
+ */
+#define TURRIS_OMNIA_BOOTCMD_RESCUE \
+	"i2c dev 2; " \
+	"i2c mw 0x2a.1 0x3 0x1c 1; " \
+	"i2c mw 0x2a.1 0x4 0x1c 1; " \
+	"mw.l 0x01000000 0x00ff000c; " \
+	"i2c write 0x01000000 0x2a.1 0x5 4 -s; " \
+	"setenv bootargs \"earlyprintk console=ttyS0,115200" \
+		" omniarescue=$omnia_reset rescue_mode=$omnia_reset\"; " \
+	"sf probe; " \
+	"sf read 0x1000000 0x100000 0x700000; " \
+	"lzmadec 0x1000000 0x1700000; " \
+	"if gpio input gpio@71_4; then " \
+		"bootm 0x1700000#sfp; " \
+	"else " \
+		"bootm 0x1700000; " \
+	"fi; " \
+	"bootz 0x1000000"
+
 #define CONFIG_EXTRA_ENV_SETTINGS \
 	RELOCATION_LIMITS_ENV_SETTINGS \
 	LOAD_ADDRESS_ENV_SETTINGS \
 	"fdtfile=" CONFIG_DEFAULT_DEVICE_TREE ".dtb\0" \
 	"console=ttyS0,115200\0" \
 	"ethact=ethernet@34000\0" \
+	"bootcmd_rescue=" TURRIS_OMNIA_BOOTCMD_RESCUE "\0" \
 	BOOTENV
 
 #endif /* CONFIG_SPL_BUILD */