Dear all:
My board is SEED-137, which is oampl137 with nand flash on board, the board works fine, it can read & run ARMUBL, DSPUBL, u-boot from NAND flash and tftp linux 2.6.18 to bootm, mount file system from NFS. It use UART1 is fine @ 115200n8.
To exercise UART booting, I follow the wiki steps "serial boot and flash loading utility for omapl137" and base on the table from sprab04d-April-2010 to change DIP switch to UART mode, and try to boot from UART. However I never see "bootme" showed.
Below is the configuration I have tried(note here the switch order is boot7, boot 3, boot2, boot 1 and boot 0):
switch(73210) baud rate result
11111 115200 nand boot successfully
11110 115200 nand boot successfully
01111 115200 nand boot successfully
00111 115200 no data shown from UART1 or UART2
00111 230400 no data shown from UART1 or UART2
10010 115200 no data shown from UART1 or UART2
10010 230400 no data shown from UART1 or UART2
11010 115200 no data shown from UART1 or UART2
11010 230400 no data shown from UART1 or UART2
11011 115200 no data shown from UART1 or UART2
11011 230400 no data shown from UART1 or UART2
The question is:
1. Since I can boot from NAND flash, how can I check ROM address 0x11700000 from linux to know what version of omapl137 I have? I have not make JTAG work fine yet.
2. How can I know from linux to know my version is version A, B or higher? (do d800k001 implies version A and d800k003 implies version B)?
3. Will "bootme" show on UART1 if I make the DIP switch to UART1 boot? Or UART2 is the only path to show bootme?
4. Is there any clue I can check to solve the boot problem?
5. What IO status ROM boot-loader will set when it acknowledge the boot mode (for example UART boot)? Input with high impedance? pull low? pull high? Output 0 or 1, or floating, since I find that each pin voltage after booting is not the value I expected with external 2K pull high or 20K pull low result.