From 67ff9e11f3971a668a0abd3efbb027ebf985b5b6 Mon Sep 17 00:00:00 2001 From: Alexey Brodkin Date: Sat, 9 Jul 2016 15:42:47 +0300 Subject: [PATCH] wandboard: move environment partition farther from u-boot.img Recently I started to notice that u-boot.img built for Wandboard by some toolchains becomes so large that it basically overlaps with U-Boot environment area on SD-card. According to http://wiki.wandboard.org/index.php/Boot-process#sdcard_boot_data_layout Wandboard's SD-card layout is as follows: ------------------------------>8--------------------------- Acked-by: Otavio Salvador Acked-by: Fabio Estevam ========================================================== 1. 0x00000000 Reserved For MBR 2. 0x00000200 512 Secondary Image Table (optional) 3. 0x00000400 1024 uBoot Image (Starting From IVT) 4. 0x00060000 393216 start of uboot env (size:8k) 5. 0x00062000 end of uboot env 6. 0x00100000 1048576 Linux kernel start 7. 0x0076AC00 7777280 start of partition 1 ------------------------------>8--------------------------- So for U-Boot we have 383kB (392192 bytes). But in up to date U-Boot for Wandboard we build separately a) SPL b) u-boot.img which gives us a bit more detailed SD-card layout: ------------------------------>8--------------------------- ========================================================== 1. 0x00000000 Reserved For MBR 2. 0x00000200 512 Secondary Image Table (optional) 3. 0x00000400 1024 SPL 4. 0x00011400 70656 u-boot.img 5. 0x00060000 393216 start of uboot env (size:8k) 6. 0x00062000 end of uboot env ... ------------------------------>8--------------------------- >From that layout we may calculate amount of space reserved for u-boot.img. It's just 315kb (322560 bytes). Now if I build U-Boot with Sourcery CodeBench ARM 2014.05 produced u-boot.img is already more than we expected (323840 bytes instead of "< 322560"): ------------------------------>8--------------------------- ls -la u-boot.img -rw-rw-r-- 1 user user 323840 Jul 5 07:38 u-boot.img ------------------------------>8--------------------------- Funny enough if I rebuild U-Boot with ARM toolchain available in my Fedora 23 distro u-boot.img becomes a little bit smaller: ------------------------------>8--------------------------- ls -la u-boot.img -rw-rw-r-- 1 user user 322216 Jul 5 07:39 u-boot.img ------------------------------>8--------------------------- What's worse this problem might not affect people most of the time because what happens people would just copy u-boot.img on SD-card and live in happiness with it... well until somebody attempts to save environment in U-Boot with "saveenv" command which will simply overwrite the very end of u-boot.img. That will lead to unusable SD-card until user dd u-boot.img on SD-card again. I may foresee this issue in the future to become more visible once we add more features in U-Boot for Wandboard or just existing code base becomes bulkier and people will consistently get larger u-boot.img files produced. IMHO there's an obvious solution for all that - just move U-Boot's env to the very end of the gap between U-Boot and the first real partition on the SD-card. This patch will follow 8fb9eea5653796 ("mx6sabre_common: Fix U-Boot corruption after 'saveenv'"). So env is still not in the very end of the gap (obviously 256kb is way too much for U-Boot's env) but at least we have now the same partitioning for i.MX6 boards. Signed-off-by: Alexey Brodkin Cc: Fabio Estevam Cc: Otavio Salvador Cc: Peter Robinson Cc: Tom Rini Cc: Peter Korsgaard Cc: Wolfgang Denk --- include/configs/wandboard.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/configs/wandboard.h b/include/configs/wandboard.h index 92af6543da..2a00ff409a 100644 --- a/include/configs/wandboard.h +++ b/include/configs/wandboard.h @@ -193,7 +193,7 @@ #define CONFIG_ENV_SIZE (8 * 1024) #define CONFIG_ENV_IS_IN_MMC -#define CONFIG_ENV_OFFSET (6 * 64 * 1024) +#define CONFIG_ENV_OFFSET (768 * 1024) #define CONFIG_SYS_MMC_ENV_DEV 0 #endif /* __CONFIG_H * */ -- 2.39.5