omap3: overo: Use software BCH8 ECC for NAND

Overo COMs have NAND flash that requires 4-bit ECC or better except for
the first sector which can use 1-bit ECC.  The boot ROM expects to load
a payload from NAND written using 1-bit hardware-based ECC.  In short,
write SPL to NAND something like this (4 times for redundancy):
 #> nandecc hw
 #> nand write ${loadaddr} 0x0 ${filesize}
 #> nand write ${loadaddr} 0x20000 ${filesize}
 #> nand write ${loadaddr} 0x40000 ${filesize}
 #> nand write ${loadaddr} 0x60000 ${filesize}

Then, switch back to software-based BCH8 for everything else:
 #> nandecc sw bch8

After [1], enlarge the max size of the SPL so the BCH code can fit.

[1] https://www.mail-archive.com/u-boot@lists.denx.de/msg163912.html

Signed-off-by: Ash Charles <ashcharles@gmail.com>
diff --git a/include/configs/omap3_overo.h b/include/configs/omap3_overo.h
index c58636a..61213df 100644
--- a/include/configs/omap3_overo.h
+++ b/include/configs/omap3_overo.h
@@ -11,6 +11,12 @@
 #define CONFIG_NAND
 
 #include <configs/ti_omap3_common.h>
+#undef CONFIG_SPL_MAX_SIZE
+#define CONFIG_SPL_MAX_SIZE	(64*1024)
+#undef CONFIG_SPL_TEXT_BASE
+#define CONFIG_SPL_TEXT_BASE	0x40200000
+
+#define CONFIG_BCH
 
 /* Display CPU and Board information */
 #define CONFIG_DISPLAY_CPUINFO
@@ -212,17 +218,22 @@
 
 /* NAND boot config */
 #define CONFIG_SYS_NAND_BUSWIDTH_16BIT	16
+#define CONFIG_SYS_NAND_MAX_ECCPOS  56
 #define CONFIG_SYS_NAND_5_ADDR_CYCLE
 #define CONFIG_SYS_NAND_PAGE_COUNT	64
 #define CONFIG_SYS_NAND_PAGE_SIZE	2048
 #define CONFIG_SYS_NAND_OOBSIZE		64
 #define CONFIG_SYS_NAND_BLOCK_SIZE	(128*1024)
 #define CONFIG_SYS_NAND_BAD_BLOCK_POS	NAND_LARGE_BADBLOCK_POS
-#define CONFIG_SYS_NAND_ECCPOS		{2, 3, 4, 5, 6, 7, 8, 9,\
-						10, 11, 12, 13}
+#define CONFIG_SYS_NAND_ECCPOS      {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, \
+					13, 14, 16, 17, 18, 19, 20, 21, 22, \
+					23, 24, 25, 26, 27, 28, 30, 31, 32, \
+					33, 34, 35, 36, 37, 38, 39, 40, 41, \
+					42, 44, 45, 46, 47, 48, 49, 50, 51, \
+					52, 53, 54, 55, 56}
 #define CONFIG_SYS_NAND_ECCSIZE		512
-#define CONFIG_SYS_NAND_ECCBYTES	3
-#define CONFIG_NAND_OMAP_ECCSCHEME	OMAP_ECC_HAM1_CODE_HW
+#define CONFIG_SYS_NAND_ECCBYTES	13
+#define CONFIG_NAND_OMAP_ECCSCHEME	OMAP_ECC_BCH8_CODE_HW_DETECTION_SW
 #define CONFIG_SYS_NAND_U_BOOT_START	CONFIG_SYS_TEXT_BASE
 #define CONFIG_SYS_NAND_U_BOOT_OFFS	0x80000
 /* NAND: SPL falcon mode configs */