LN2410SBC board (from littlechips.com): S3C2410 SoC, ARM920T, u-boot, Linux-2.4 and Linux-2.6. I have a JTAG cable, it uses the triton cable type and I am able to use openocd with it.
I would like to know if it is possible to run an application from SDRAM using openocd such that it is run as if from power on of the board? The original bootloader at 0x0000_0000 on flash shouldn’t execute and this application should run as if it were the first one to run?
Is it possible? Appreciate any tutorials/documentation links.
It’s possible with most ARM920t (at least the ones I’ve seen so far), but not with the “Triton” cable type - you need control of the nSRST line, not only nTRST. The Olimex ARM-JTAG for example is perfectly fine, but most other clones should work, too, provided they offer both reset signals.
You should just change the reset type in the "target … " line to “reset_halt” or possibly “reset_init”, if you want it to execute an initialization script, too. Issue a reset, or set the “daemon_startup reset” (instead of attach), and your target should wait for you at 0x00000000.
You should then initialize the SDRAM controller and possibly the PLL (if necessary for SDRAM operation), before you’re able to load code into SDRAM.
Of course, that way you can’t debug everything - the setup of the SDRAM controller has to be done using the debugger, and can’t be repeated by your application after that.
If you want to debug the whole initialization process you have to write your code to flash, then use “reset_halt” to debug right out of reset.