I carefully read the codes related to the do_go function, and I find
that(u
boot 1.1.6): In do_go() functions: #if defined(CONFIG_I386) /* * x86 does not use a dedicated register to pass the pointer * to the global_data */ argv[0] = (char *)gd; #endif
But in app_startup function: void app_startup(char **argv) { unsigned long * cp = &__bss_start;
/* Zero out BSS */ while (cp < &_end) { *cp++ = 0; }
#if defined(CONFIG_I386) /* x86 does not have a dedicated register for passing
global_data */
global_data = (gd_t *)argv[-1]; jt = global_data->jt; #endif }
The gd is not in the same place :see do_go is argv[0], and app_startup
is (gd_t
*)argv[-1].
But later I modified the global_data = (gd_t *)argv[-1]; in
app_startup
function to global_data = (gd_t *)argv[0], the change still does not
make sense.
Any ideas? Maybe I should change the argv[0] = (char *)gd; in do_go
function
to argv[-1] = (char *)gd;
Later, I tried remove the function bodies, and the main function like this: int _main (int argc, char *argv[]) { return (8); } And got the following result: boot > go 01000000 ## Starting application at 0x01000000 ... ## Application terminated, rc = 0x8
I am sure app_startup and do_go are not consistent, so I can not use any printf or some other function calls.
Currently I can not update the flash as I do not have jtag tools. Later I will update flash and see if it could fix the problem.
Thanks in advance