DSPLink shared memory errors when remapping Linux and DSP

Bryce Lembke

Other Parts Discussed in Thread: DM3730, OMAP3530

I have followed the instructions for changing the memory mapping of Linux and the DSP found at http://processors.wiki.ti.com/index.php/Changing_DSPLink_Memory_Map

My ARM side app and DSP app are running fine except that the I can no longer get my buffers transferred back and forth using DSPLink (specifically ring_io). This was working fine before I changed the memory addresses. Interestingly, I can still print DSP app debug traces on the ARM side app, so I believe I at least have the addressing setup correctly for the ARM and DSP applications.

I have changed the allocation to be 256M for ARM and 256M for DSP on my Gumstix Overo IronStorm (DM3730).

Here is an excerpt from dsplink-omap3530-base.tci

…

prog.module("GBL").C64PLUSMAR128to159 = 0x1FFF0000 ;/* Make sure DSPLINKMEM segment is NOT cached */

…

/* ============================================================================

* MEM : RESET_VECTOR

* ============================================================================

var RESET_VECTOR = prog.module("MEM").create("RESET_VECTOR");

RESET_VECTOR.base = 0x90000000 ;

RESET_VECTOR.len = 0x00000080;

RESET_VECTOR.space = "code/data";

RESET_VECTOR.createHeap = false;

RESET_VECTOR.comment = "RESET_VECTOR";

/* ============================================================================

* MEM : Adjust DDR2

* ============================================================================

var DDR2 = prog.module("MEM").instance("DDR2");

DDR2.base = RESET_VECTOR.base + RESET_VECTOR.len ;

DDR2.len = 0x8FFFF80;

DDR2.space = "code/data";

DDR2.createHeap = true;

DDR2.heapSize = 0x8000000;

DDR2.comment = "DDR2";

/* ============================================================================

* MEM : DSPLINKMEM

* ============================================================================

var DSPLINKMEM = prog.module("MEM").create("DSPLINKMEM");

DSPLINKMEM.base = DDR2.base + DDR2.len ;

DSPLINKMEM.len = 0x00030000;

DSPLINKMEM.createHeap = false;

DSPLINKMEM.comment = "DSPLINKMEM";

/* ============================================================================

* MEM : DSPLINKMEM

* ============================================================================

var POOLMEM = prog.module("MEM").create("POOLMEM");

POOLMEM.base = DSPLINKMEM.base + DSPLINKMEM.len ;

POOLMEM.len = 0xD0000;

POOLMEM.createHeap = false;

POOLMEM.comment = "POOLMEM";

Here is an excerpt from CFG_OMAP3530_SHMEM.c

#define RSTENTRYID 0u

#define RESETCTRLADDR 0x90000000u

#define RESETCTRLSIZE 0x80u

#define CODEENTRYID 1u

#define CODEMEMORYADDR (RESETCTRLADDR + RESETCTRLSIZE)

#define CODEMEMORYSIZE 0x8FFFF80u

#define SHAREDENTRYID0 2u

#define SHAREDMEMORYADDR0 (CODEMEMORYADDR + CODEMEMORYSIZE)

#define SHAREDMEMORYSIZE0 0x5000u

#define SHAREDENTRYID1 3u

#define SHAREDMEMORYADDR1 (SHAREDMEMORYADDR0 + SHAREDMEMORYSIZE0)

#define SHAREDMEMORYSIZE1 0x2B000u

#define POOLENTRYID 4u

#define POOLMEMORYADDR (SHAREDMEMORYADDR1 + SHAREDMEMORYSIZE1)

#define POOLMEMORYSIZE 0x000D0000u

over 12 years ago

0 janet over 12 years ago

TI__Mastermind 22760 points

Hi Bryce,

Are you able to run the DspLink RingIO sample with your memory map changes? If not, you could try backing out the memory map changes, then adding in the changes one at a time, until it no longer works. Usually when there is a memory map conflict between the Arm and the DSP, PROC_start() will fail. What kind of failure behavior are you seeing?

Also, what version of DSPLink are you using? You could attach the CFG.c and .tci files so that I can diff them with what's in the product.

Best regards,

Janet

0 Bryce Lembke over 12 years ago in reply to janet

Intellectual 310 points

Thanks for the response. I found the issue. The root of my problem was caching. Prior to my remap, the DSPLink shared memory was outside of the cachable region specified in the .tci file.

prog.module("GBL").C64PLUSMAR128to159 = 0x00000080 ;

When I changed everything in the DSP space to be cacheable (0xFFFF0000), my data going back to the ARM side was not correct since the DSP wasn't Invalidating the cache before releasing the buffer.

If I use the write buffer instead of the same read buffer to write stuff back or if I do a HAL_cacheWbInv on the read buffer, it works fine.

Bryce

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DSPLink shared memory errors when remapping Linux and DSP