board: axy17lte: get board usable - add bootcmd and docs
U-boot is intended to replace linux kernel in android boot image(ABL), and
it's FIT payload to replace initramfs file. The boot process is similar to
boot image with linux:
- android bootloader (ABL) unpacks android boot image
- ABL sets `linux,initrd-start property` in chosen node in unpacked FDT
- ABL sets x0 register to FDT address, and passes control to u-boot
- u-boot reads x0 register, and stores it in `prevbl_fdt_addr` env variable
- u-boot reads `linux,initrd-start` property,
and stores it in `prevbl_initrd_start_addr`
In this way, u-boot bootcmd relies on `prevbl_initrd_start_addr` env
variable, and boils down to `bootm $prevbl_initrd_start_addr`.
If more control on boot process is desired, pack a boot script in
FIT image, and put it to default configuration
What done:
- Rearrange defconfig option order
- Add CONFIG_SAVE_PREV_BL_* options
- Doc updates:
- remove wrong SBOOT memory corruption note, because
memory is changed during u-boot bringup process,
not by SBOOT
- put payload on ramdisk place in abl boot image
creation step
Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
diff --git a/include/configs/exynos78x0-common.h b/include/configs/exynos78x0-common.h
index 53396aa..457057c 100644
--- a/include/configs/exynos78x0-common.h
+++ b/include/configs/exynos78x0-common.h
@@ -35,6 +35,7 @@
#define CONFIG_SYS_SDRAM_BASE 0x40000000
#define CONFIG_SYS_INIT_SP_ADDR (CONFIG_SYS_TEXT_BASE + SZ_2M - GENERATED_GBL_DATA_SIZE)
+#define CONFIG_SYS_BOOTM_LEN SZ_32M
/* DRAM Memory Banks */
#define SDRAM_BANK_SIZE (256UL << 20UL) /* 256 MB */
#define PHYS_SDRAM_1 CONFIG_SYS_SDRAM_BASE
@@ -79,7 +80,10 @@
#define EXYNOS_FDTFILE_SETTING
#endif
+/* Cannot use bootdelay > 0, because timer is not working */
#define EXTRA_ENV_SETTINGS \
+ "bootdelay=0\0" \
+ "bootcmd=source $prevbl_initrd_start_addr:bootscript\0" \
EXYNOS_DEVICE_SETTINGS \
EXYNOS_FDTFILE_SETTING \
MEM_LAYOUT_ENV_SETTINGS