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LS1043ARDB SD Boot Questions

Question asked by Don Berkowitz on Feb 3, 2016
Latest reply on Feb 5, 2016 by bpe

I have a new LS1043ARDB board and am trying to reconfigure it to boot from an SD Chip.  The default boot procedure works fine.  I am connected via the serial line console RJ45 (UART1) and with the default boot, I see an expected message stream and can log in as root.


I am having difficulty understanding the boot options and would like some clarifications:


1) My understanding is that the board initially loads some simple U-Boot code from a ROM, then, based on the hardware switch settings in SW blocks 4 and 5, locates a place to load a more-extensive build of U-Boot, either from NOR, NAND, or the SD card.  Is this correct?


2) Is it true that I can start U-Boot from the NOR flash copy and still configure U-Boot to boot Linux from the SD card or other media, or do they all have to be on the same media?


3) If I do not modify the hardware switches from the factory default positions, but configure U-Boot to boot Linux from the SD disk, Linux appears to start.  The U-boot configuration is two commands from the SDK PDF (plus a save):

   setenv bootcmd "ext2load mmc 0 a0000000 kernel.itb && bootm a0000000"

   setenv bootargs "root=/dev/mmcblk0p1 rw earlycon=uart8250,0x21c0500,115200 console=ttyS0,115200"


However, if I modify the switches to boot from the SD card, the system hangs hopelessly without producing any console log data.  The switch settings are as follows: I will refer to the switches by the number on the switch, ranging from 1 to 8.  The SDK PDF Section 3.4.2 says to boot from SD, Switch 1 in Switch Block 5 should be set to zero/off.  It also says that in Switch Block 4, only Switch 3 should be 1/on. Correct?


I have loaded an SD chip with my Linux build as per the 0.5 SDK PDF although in all honesty, I am not yet sure I have the chip properly programmed.  What concerns me is that no console messages appear, suggesting that U-Boot cannot even begin to start, let alone load from the SD chip.


4) Note the reference in the u-boot command in the sdk is to kernel.itb.  Such a file is not generated by any of the builds I have found.  Is the command incorrectly documented?  Which build is supposed to build the right kernel file?