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Altera_Forum's avatar
Altera_Forum
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21 years ago

uClinux .data segment in SDRAM?

For a number of reasons, I'd like to run my kernel in SRAM but allocate data memory (i.e. socket buffers) in SDRAM. This seems possible with a NIOS 'Hello World' application, or the like...
Altera_Forum's avatar
Altera_Forum
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21 years ago

If you want to leave a hole between the two zones, there is more work to do. You can no longer use the function free_area_init, you have to call free_area_init_node, in paging_init.

If you want to stick to the simpler free_area_init, you have to tell it the actual size of your SDRAM. The flip side is you will waste a lof of memory on the paging structures (there are two many pages).

My advice is, right now stick to free_area_init and give all 1G sdram to Linux, make sure it works. In the future you can use free_area_init_node.