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Altera_Forum
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15 years ago

Problem with MMU with a custom board

Good Afternoon. Hello, I have an custom FPGA board which have an CycloneII and a SDRAM of 32MBit I have been developing without MMU for a long time, but I come to the need of having C++ an...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

The same reason because I compared it with the neek_web_server_mmu, because it uses 32 MB the same I got.

I think that it has to do with the reset and exception vector. In the neek_web_server_mmu I see that they are FLASH and SSRAM respectibely, but in the file linux-2.6/arch/nios2/boards/neek/include/asm/nios.h they uses the SDRAM to the kernel: 


# elif defined(CONFIG_NIOS2_CUSTOM_FPGA)
....
# define DDR2_TOP_BASE DDR_SDRAM_BASE
# define DDR2_TOP_SPAN DDR_SDRAM_SPAN
....

In my proyect I have the reset and exception vector in my only external RAM, could that be the problem?