spl: nand: support redundant u-boot image
On modern NAND it's more than recommended to have a backup copy of the
u-boot binary to recover from corruption: bitflips are quite common on
MLC NANDs, and the read-disturbance will corrupt your u-boot partitition
more quickly than what you would see on an SLC NAND.
Add an extra Kconfig option to specify the offset of the redundant u-boot
image.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
[scottwood: added ifdef to fix build break]
Signed-off-by: Scott Wood <oss@buserror.net>
diff --git a/common/spl/spl_nand.c b/common/spl/spl_nand.c
index 7cf0d1b..0e35e0f 100644
--- a/common/spl/spl_nand.c
+++ b/common/spl/spl_nand.c
@@ -134,6 +134,13 @@
#endif
/* Load u-boot */
err = spl_nand_load_element(CONFIG_SYS_NAND_U_BOOT_OFFS, header);
+#ifdef CONFIG_SYS_NAND_U_BOOT_OFFS_REDUND
+#if CONFIG_SYS_NAND_U_BOOT_OFFS != CONFIG_SYS_NAND_U_BOOT_OFFS_REDUND
+ if (err)
+ err = spl_nand_load_element(CONFIG_SYS_NAND_U_BOOT_OFFS_REDUND,
+ header);
+#endif
+#endif
nand_deselect();
return err;
}
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 5fe169f..8c46a2f 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -117,6 +117,14 @@
Set the offset from the start of the nand where u-boot should be
loaded from.
+config SYS_NAND_U_BOOT_OFFS_REDUND
+ hex "Location in NAND to read U-Boot from"
+ default SYS_NAND_U_BOOT_OFFS
+ depends on SYS_NAND_U_BOOT_LOCATIONS
+ help
+ Set the offset from the start of the nand where the redundant u-boot
+ should be loaded from.
+
config SPL_NAND_DENALI
bool "Support Denali NAND controller for SPL"
help