Hi, My target is a omap850 based GP(general purpose, not HS) board. I got x-loader from http://linux.omap.com The x-loader is ok with JTAG in memory, but if I flashed it to NAND problem. X-loader won't work. So, I did a little experiment as follows. I modified x-loader and inserted a gpio trigger(I pull a gpio to high) in start_armboot(the first c call after start.S ). Compiled and executed x-loader in memory using TI JTAG successfully, and the gpio will behave as I expect. But if I flashed the code to NAND flash. The gpio won't trigger, however if I insert the gpio trigger in the start.S. The gpio will be triggered. (both in start_armboot and in start.S will work in memory using JTAG) So, I suspect that something wrong when cpu jumps from assembly to c code. I'm trying to figure out what's going on. Has anyone met this before? Thanks in advance. The gpio trigger code is as follows. I execute it in assembly using "bl trigger_gpio16". Define extern void trigger_gpio16(void), and call trigger_gpio16() in C. . trigger_gpio16: LDR R2, =0xFFFE1074 LDR R3, [R2] BIC R3, R3, #0xE0000 STR R3, [R2] LDR R3, [R2] ORR R3, R3, #0xD0000 STR R3, [R2] LDR R2, =(OMAP850_GPIO_BASE_1+GPIO_DIRECTION_CONTROL) LDR R3, [R2] BIC R3, R3, #0x10000 STR R3, [R2] LDR R2, =(OMAP850_GPIO_BASE_1+GPIO_DATA_OUTPUT) LDR R3, [R2] ORR R3, R3, #0x10000 //BIC R3, R3, #0x10000 STR R3, [R2] MOV pc, lr -- ---- Tim. - To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
