ESP8266 Developer Zone

Re: os_printf with a char pointer parameter causes an exception

2017-09-15T18:52:49+08:00

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.

Statistics: Posted by ddze7374 — Fri Sep 15, 2017 6:52 pm

Re: os_printf with a char pointer parameter causes an exception

2017-09-14T04:05:55+08:00

ddze7374 wrote:
Code:
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:

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.

ddze7374 wrote:
Solved , the flash needs an access to the aligned data.

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

Statistics: Posted by jcmvbkbc — Thu Sep 14, 2017 4:05 am

Re: os_printf with a char pointer parameter causes an exception

2017-09-14T01:10:58+08:00

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

Statistics: Posted by ddze7374 — Thu Sep 14, 2017 1:10 am

os_printf with a char pointer parameter causes an exception

2017-09-13T22:28:16+08:00

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:

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 ?

Statistics: Posted by ddze7374 — Wed Sep 13, 2017 10:28 pm