os_printf with a char pointer parameter causes an exception

[ddze7374]

Hello,

I am trying to debug some code and need to display the content of the char pointer. But everytime it gives an exception.

Code: Select all

static void ICACHE_FLASH_ATTR someCb(const char *data){
   os_printf( "LED = %s", *data);
}


Fatal exception 28(LoadProhibitedCause):
epc1=0x40245abe, epc2=0x00000000, epc3=0x40246461, excvaddr=0x00000023, depc=0x00000000
ÿ
ets Jan 8 2013,rst cause:2, boot mode:(1,6)

Is there a way to access the content of this pointer ?

By the way is there a downloadable xtensa-lx106-elf-gdb debugger ?

[ddze7374]

Solved , the flash needs an access to the aligned data.

[jcmvbkbc]

Code: Select all

static void ICACHE_FLASH_ATTR someCb(const char *data){
   os_printf( "LED = %s", *data);
}


Fatal exception 28(LoadProhibitedCause):
epc1=0x40245abe, epc2=0x00000000, epc3=0x40246461, excvaddr=0x00000023, depc=0x00000000
ÿ
ets Jan 8 2013,rst cause:2, boot mode:(1,6)

The call to os_printf should be

Code: Select all

os_printf( "LED = %s", data);

without dereferencing data. Otherwise you use the value of the first character of data as a pointer, which points to 0x00000023 in your case (that's the value of excvaddr), which is wrong.

Solved , the flash needs an access to the aligned data.

The original problem doesn't seem to have anything related to data alignment.

[ddze7374]

jcmvbkbc,

you beleive I have not tried without the dereferencing "star"?

Only, I agree with you that does take the pointer, not the dereferenced value like I described.
But in either case did not work for me.