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?