Malloc on PowerPC on VirtexII pro

Nov 07, 2005 2 Replies

hi,



I'm using a PPC405 on a Virtex2 pro. I try to allocate memory with malloc() function. It compiles without any problem but malloc returns NULL => no memory is allocated. I set the heap size at 0x0800 in docm. I set need_xil_malloc to false since xil_malloc seems to be used only for MicroBlaze.



What's wrong ?



Thanks for answer.



Tibo



ISE 7.1 / EDK 7.1 / SDK with no kernel


Are you using a custom linker script? The STACK_SIZE and HEAP_SIZE variables are only used by the linker script.

If you add --verbose to the -Wl linker options (Applications/Compiler Options/Advanced) the linker script will be output when you compile. This is also a good way to get the default linker script to read and modify.

If your memory space is contiguous, (ie. it just has a start address, followed by text, followed by data, followed by bss) you should probably just be using the default linker script.

If you need to use a custom linker script you need to read the default linker script to see what it does with HEAP_SIZE, and modify your custom linker script.

Alan Nishioka snipped-for-privacy@nishioka.com

How much memory are you trying to allocate? 0x800 is only 2KB. Instead of using heap that small it might be better to allocate static data structures anyway.

- Peter

Tibo wrote:

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