[U-Boot] Can not access global variable in uboot command function?

mips64 , xlr732

I've added a test command in uboot, say, U_BOOT_CMD(test_globa,...do_test_global) ,which is in cmd_command.c .

And in cmd_command.c, there is also a global string array ,say ,char* p = "test";

In do_test_global, I used pointer to access elements of array p like this:

char c = *(char*)p;

it seemd that , the code above caused uboot dead and print nothing ,I guess that,maybe there was a memory access violation.

Any suggestions on how could this happended? Thank you in advance

my code is like this:

/* cmd_command.c*/

char* p = "test";

U_BOOT_CMD(test_globa,do_test_global) ;

int do_test_global() { char c = *(char*)p; //when called , uboot was dead here... return 0; }