Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Mutex - uClinux (without mmu)

Hi I have a project thar includes 2 NIOS2 CPUs. Both need to access the same memory area in an SRAM. One of the CPUs runs software developed with the NIOS2 IDE, another runs uClinux. ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

I might be off on this -- I'm not sure what the outl/inl macros do in uClinux, they might take care of this.

Without an MMU, the NIOS uses bit 31 to flag cached or uncached accesses. Since you have two processors accessing that memory, you have to set it to make sure the access is uncached. So you actually have to read/write 0x80000000