malloc returning pointer to memory used for globals ... ?!

Guest · Posted: Tue Dec 16, 2003 4:40 am

Hello everyone,

After 6 hours of debugging printf pain I discovered that a call to malloc() for 16 bytes gives me a RAM address already used by some globals. Writing to the malloc()'d pointer trashes them.

By looking in the .SYM file I can see exactly what is being trashed, and printf() debugging has verified the overwrite.

Has anyone used malloc successfully in a real program? (not a toy thing like ex_malloc.c)

Another CCS bug derailment, it looks like.

Advice?
(I really do need a malloc() type functionality)

Jesse

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

One solution would be to use #reserve to reserve a large block of ram,
and then write your own malloc() routine, to let you allocate and release
blocks of that ram. I'm sure there is code for this all over the net.
Here's a post from comp.arch.embedded that has source code for it.
http://groups.google.com/groups?&selm=01bd00c1%24817a3580%24LocalHost%40rusaneanu

Edited to add:
Actually, upon searching further, I found that CCS has the source
code in stdlibm.h, which is in this folder: c:\Program Files\Picc\Drivers