[cdt-dev] CDT/GDB issue

["Derek Morris" <dmsubs@xxxxxxxxxxxxx>]

Hi,

I am using Eclipse to debug an embedded system. The embedded system has a
sparse memory map. That is, it is not a contiguous space. If I try to access
non-existant memory, I get memory faults.

I have a valid memory space that starts at 0xff000000. In the Eclipse memory
viewer, if I try to display this address, each memory location is displayed
as "??????". If I do this in GDB, it reads correctly.

Looking at the MI debug trace:

[1,146,900,580,732] 68-data-read-memory 4278189760 x 1 1 976
[1,146,900,580,752]
68^done,addr="0xfefffec0",nr-bytes="0",total-bytes="976",next-row="0xff00029
0",p\
rev-row="0xfefffaf0",next-page="0xff000290",prev-page="0xfefffaf0",memory=[{
addr="0xfefffec0",data=[\
"N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A
","N/A","N/A","N/A","N/A\
","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N
/A","N/A","N/A","N/A","N\
/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A",
"N/A","N/A","N/A","N/A",\
"N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A
","N/A","N/A","N/A","N/A\
","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N/A","N
/A",
Etc

It is reading memory from 0xfefffec0 (4278189760), which in my system is
invalid. I assume this is to cache the memory before (and after) the data I
want. GDB seems to be returning invalid data for the whole requested block
(inlcuding the valid memory).

Can I stop Eclipse doing this (requesting memory before the adsress I want)?
Is GDB at fault for returning invalid data over the whole block?

Any help/advise/pointers gratefully received.

---
Derek