Problem using DSPLINK API to add a MMU section to map GPMC CS1 space on OMAP3

Susan Tremel

Other Parts Discussed in Thread: OMAP3530

I'm using the OMAP3530 and the DVSDK 4. I need to access the GPMC CS1 (0x08000000) region from the DSP. I tried using the PROC_CTRL_CMD_MMU_ADD_ENTRY API described in LNK_181_DES.pdf to map this region to DSP memory space with no luck.

After reviewing the DSPLINK HAL code it seems like it will only set up a mapping if the virtual address and the physical address are equal and in my case they can't be because 0x8000000 is a reserved area in the DSP memory map.

I ended up doing the mapping from a different driver, but this is problematic since the dsplink driver blindly resets the mmu without seeing if it is being used.

Is there a fix for this problem or a suggestion on a better way of handling this?

Susan

over 14 years ago

0 Vaibhav Hiremath over 14 years ago

TI__Expert 8180 points

Hi,

I am neither DSPLink nor DSP expert, but one suggestion I can provide here is, you can change the CS1 memory map (GPMC_CONFIG7) to something which is acceptable to DSP.

Thanks,

Vaibhav

0 Ramsey over 14 years ago in reply to Vaibhav Hiremath

TI__Genius 12025 points

Usually, Linux is loaded at the beginning of external memory, 0x80000000. The DSP should not be accessing the same memory used by Linux. Would you provide the memory map you are using and please indicate where Linux is loaded.

~ Ramsey

0 Susan Tremel over 14 years ago in reply to Vaibhav Hiremath

Prodigy 80 points

Thanks Vaibhav. I'll look into this. Susan

0 Susan Tremel over 14 years ago in reply to Ramsey

Prodigy 80 points

I do have Linux loading at 0x80000000. The GPMC CS1 bus address space I was referring to was at 0x08000000. Thanks for the post, Susan

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Problem using DSPLINK API to add a MMU section to map GPMC CS1 space on OMAP3