The default U-Boot offset for the Allwinner SoCs was set to 32kB.
This was probably to try to maintain some compatibility with the current image that we build for the MMC where the U-Boot binary is also located at a 32kB offset.
However, this causes a number of issues. The first one is that it prevents us from using a backup SPL entirely, which is troublesome in case where the first would be corrupt (especially on MLC which have a higher number of bitflips).
We also cannot use the original MMC image on the NAND, because we need to prepare the SPL image to include the ECCs and randomizer settings, which reduces the interest of setting it at that particular offset.
It also prevents us from upgrading and flashing the U-Boot and SPLs independantly, since it's very likely that it will fall in the same erase block.
Since that default wasn't used by any board, change it for 8MB, which will be in an erase block of its own, all the erase blocks being multiple of two. The highest erase block size we encountered is 4MB, which means that in this particular setup, the first and second erase blocks will be for the SPL and its backup, and the third for U-Boot.
Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com --- drivers/mtd/nand/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig index 2cc9e513d2e9..505102440609 100644 --- a/drivers/mtd/nand/Kconfig +++ b/drivers/mtd/nand/Kconfig @@ -121,7 +121,7 @@ config SYS_NAND_U_BOOT_LOCATIONS
config SYS_NAND_U_BOOT_OFFS hex "Location in NAND to read U-Boot from" - default 0x8000 if NAND_SUNXI + default 0x800000 if NAND_SUNXI depends on SYS_NAND_U_BOOT_LOCATIONS help Set the offset from the start of the nand where u-boot should be