[U-Boot] [PATCH] env: ti: boot: Handle reboot reason from BCB

[Sam Protsenko]

In case of Android boot, reboot reason can be written into BCB (usually
it's an area in 'misc' partition). U-Boot then can obtain that reboot
reason from BCB and handle it accordingly to achieve correct Android
boot flow, like it was suggested in [1]:
  - if it's empty: perform normal Android boot from eMMC
  - if it contains "bootonce-bootloader": get into fastboot mode
  - if it contains "boot-recovery": perform recovery boot

The latter is not implemented yet, as it depends on some features that
are not implemented on TI platforms yet (in AOSP and in U-Boot).

[1] https://marc.info/?l=u-boot&m=152508418909737&w=2

Signed-off-by: Sam Protsenko <semen.protsenko at linaro.org>
---
 include/environment/ti/boot.h | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/include/environment/ti/boot.h b/include/environment/ti/boot.h
index 54e9b2de4d..e37004af46 100644
--- a/include/environment/ti/boot.h
+++ b/include/environment/ti/boot.h
@@ -98,6 +98,10 @@
 #define AB_SELECT ""
 #endif
 
+#define FASTBOOT_CMD \
+	"echo Booting into fastboot ...; " \
+	"fastboot " __stringify(CONFIG_FASTBOOT_USB_DEV) "; "
+
 #define DEFAULT_COMMON_BOOT_TI_ARGS \
 	"console=" CONSOLEDEV ",115200n8\0" \
 	"fdtfile=undefined\0" \
@@ -117,6 +121,27 @@
 		"setenv mmcroot /dev/mmcblk0p2 rw; " \
 		"run mmcboot;\0" \
 	"emmc_android_boot=" \
+	"if bcb load " __stringify(CONFIG_FASTBOOT_FLASH_MMC_DEV) " misc; " \
+	"then " \
+		"if bcb test command = bootonce-bootloader; then " \
+			"echo BCB: Bootloader boot...; " \
+			"bcb clear command; bcb store; " \
+			FASTBOOT_CMD \
+		"elif bcb test command = boot-recovery; then " \
+			"echo BCB: Recovery boot...; " \
+			"echo Warning: recovery boot is not implemented; " \
+			"echo Performing normal boot for now...; " \
+			"run emmc_android_normal_boot; " \
+		"else " \
+			"echo BCB: Normal boot requested...; " \
+			"run emmc_android_normal_boot; " \
+		"fi; " \
+	"else " \
+		"echo Warning: BCB is corrupted or does not exist; " \
+		"echo Performing normal boot...; " \
+		"run emmc_android_normal_boot; " \
+	"fi;\0" \
+	"emmc_android_normal_boot=" \
 		"echo Trying to boot Android from eMMC ...; " \
 		"run update_to_fit; " \
 		"setenv eval_bootargs setenv bootargs $bootargs; " \
@@ -176,8 +201,7 @@
 	"if test ${dofastboot} -eq 1; then " \
 		"echo Boot fastboot requested, resetting dofastboot ...;" \
 		"setenv dofastboot 0; saveenv;" \
-		"echo Booting into fastboot ...; " \
-		"fastboot " __stringify(CONFIG_FASTBOOT_USB_DEV) "; " \
+		FASTBOOT_CMD \
 	"fi;" \
 	"if test ${boot_fit} -eq 1; then "	\
 		"run update_to_fit;"	\
-- 
2.20.1