>From: [email protected] >Hello, > >Thanks to the help I obtained on this mailing list, I've been able to >customize u-boot (2013.10 release) to work on a custom omap4460 board. >Schematically, it's similar to the pandaboard, but uses the twl6032 >pmic and has a NAND memory from micron present. > >I've been able to boot this board from USB and from an external mmc >card. In both cases, I've been able to access the nand memory (i.e. >reading/writing). My team tried writing an image of the linux kernel >to the nand from mmc, rebooted the board, copied the image from nand >to ddr and booted off it. At the very least, we feel that this shows >that the memory is working properly. > >The problem I'm facing is that I can't seem to boot directly from the >nand memory chip. We've set the boot configuration pins to start with >NAND boot, but it doesn't seem to work. On probing the CS and >nand-busy lines we can see some activity happening, but don't >understand what it means. > >The way I expect the board to work, is that the ROM code should detect >the external nand present, query for ONFI data, configure the >bus/interface accordingly, copy SPL part of bootloader from first >sector to internal sram and boot off that. > >I *think* that the omap4460 is sending the ONFI request, but after >that, something malfunctions, nand is deemed unusable and the next >device in boot sequence is queried. In my case its the uart and I can >see some garbage characters coming out on the console. > >Any suggestions on how I could debug this? > If this NAND has bus-width = 16, then you need to tweak the board file with following changes. Below code is for AM335x platforms, you need similar for omap4 platforms ------------------------------ --- arch/arm/cpu/armv7/am33xx/mem.c +++ arch/arm/cpu/armv7/am33xx/mem.c @@ -64,7 +64,7 @@ u32 base = CONFIG_SYS_FLASH_BASE; #elif defined(CONFIG_NAND) /* configure GPMC for NAND */ - const u32 gpmc_regs[GPMC_MAX_REG] = { M_NAND_GPMC_CONFIG1, + const u32 gpmc_regs[GPMC_MAX_REG] = { M_NAND_GPMC_CONFIG1 | 0x1000, M_NAND_GPMC_CONFIG2, M_NAND_GPMC_CONFIG3, M_NAND_GPMC_CONFIG4, ------------------------------
with regards, pekon _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
