PROCESSOR-SDK-OMAPL138: Understanding The IPC/MessageQ communication flow with Sys/bios & Linux

Hi Jianzhongxu,

That sounds great.

Makes  sense, but is the DSP able to at all use the LAD daemon in any way. Is it only accesible in Linux?

To me it seems like that the ARM is able to open queues both remotely and locally because of the LAD Daemon, but the DSP can only open queues locally?

Kim Nielsen said:

Makes  sense, but is the DSP able to at all use the LAD daemon in any way. Is it only accesible in Linux?

LAD daemon is only available in Linux, not in RTOS.

Kim Nielsen said:

To me it seems like that the ARM is able to open queues both remotely and locally because of the LAD Daemon, but the DSP can only open queues locally?

DSP can open queues created by ARM. It's just that the queue needs to be created by ARM first. You can do MessageQ_open() in a while loop as what's currently done on ARM. If DSP runs first, MessageQ_open() will return MessageQ_E_NOTFOUND until ARM runs the application which creates the message queue that DSP tries to open.

Hi Jianzhongxu,

In my application, the DSP starts before the ARM.

This is what I do on the DSP if I try to open a queue (HOST:dspsystem) created by the ARM:

Int status;

do {
      status = MessageQ_open( "HOST:dspsystem", &RemotequeId);
      if (status == MessageQ_E_NOTFOUND) {
        Task_sleep(1);
      }
    } while(status == MessageQ_E_NOTFOUND);

This is what I do when I create the queue (HOST:dspsystem) on the ARM:

Char cbuf[48];
MessageQ_Params messageQParams;
MessageQ_Handle  localMessageQ = NULL;

/* Create local MessageQ handler */
sprintf(cbuf, "%s:%s", HOST, dspsystem);

MessageQ_Params_init(&messageQParams);
localMessageQ = MessageQ_create(cbuf, &messageQParams);

On the DSP, the MessageQ_open() function keeps returning MessageQ_E_NOTFOUND.
According to "SYS/BIOS Inter-Processor Communication" user guide, the MessageQ_open() internally calls NameServer_get().

Link to user guide: user_guide

In Linux, I understand that the NameServer_get() call makes use of the LAD daemon to look for queues on the DSP. I guess this is why MessageQ_open() works fine on the ARM.

But how does the DSP locate any queues on the ARM, does it make use of something similar to the LAD daemon perhaps?

Thank you & regards,
Kim

Hi Kim,

Kim Nielsen said:

But how does the DSP locate any queues on the ARM, does it make use of something similar to the LAD daemon perhaps?

It uses NameServer_get(), as described here.

I tried to call MessageQ_open() on DSP to open a queue to be created by the ARM as well. Initially I constantly saw message "virtio_rpmsg_bus virtio0: msg received with no recipient", but once I started ARM application by "./app_host DSP", that message stopped and everything worked fine.

BTW, I saw you have the following in your code:

sprintf(cbuf, "%s:%s", HOST, dspsystem);

Did you miss the double quote before and after HOST and dspsystem?

Regards,

Jianzhong

Hi Jianzhongxu,

Are you testing with any IPC example, if yes which one are you using?
Could you perhaps attach the example here?

Yes I missed the double quotes, when I inserted the code here on the forum...

When I call MessageQ_open() on the DSP I do not get "virtio_rpmsg_bus virtio0: msg received with no recipient".

I noticed that if I insert a printf after the Task_sleep(1) I get no printf output. But if I insert the printf before the task_sleep I the printf output can be seen:

Int status;

do {
      status = MessageQ_open( "HOST:dspsystem", &RemotequeId);
      if (status == MessageQ_E_NOTFOUND) {
        Task_sleep(1);
        System_printf("Test...\n");
      }
    } while(status == MessageQ_E_NOTFOUND);

Hi Kim,

I was testing IPC example ex02_messageq. Please see modified ipc_3_50_04_08/examples/OMAPL138_linux_elf/ex02_messageq/dsp/server.c in the attachment.

/*
 * Copyright (c) 2013-2014, Texas Instruments Incorporated
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * *  Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * *  Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * *  Neither the name of Texas Instruments Incorporated nor the names of
 *    its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 *  ======== Server.c ========
 *
 */

/* this define must precede inclusion of any xdc header file */
#define Registry_CURDESC Test__Desc
#define MODULE_NAME "Server"

/* xdctools header files */
#include <xdc/std.h>
#include <xdc/runtime/Assert.h>
#include <xdc/runtime/Diags.h>
#include <xdc/runtime/Log.h>
#include <xdc/runtime/Registry.h>

#include <stdio.h>

/* package header files */
#include <ti/ipc/MessageQ.h>
#include <ti/ipc/MultiProc.h>

#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Task.h>

/* local header files */
#include "../shared/AppCommon.h"

/* module header file */
#include "Server.h"

/* module structure */
typedef struct {
    UInt16              hostProcId;         // host processor id
    MessageQ_Handle     slaveQue;           // created locally
    MessageQ_QueueId    hostQue;            // created by the host
} Server_Module;

/* private data */
Registry_Desc               Registry_CURDESC;
static Server_Module        Module;


/*
 *  ======== Server_init ========
 */
Void Server_init(Void)
{
    Registry_Result result;

    /* register with xdc.runtime to get a diags mask */
    result = Registry_addModule(&Registry_CURDESC, MODULE_NAME);
    Assert_isTrue(result == Registry_SUCCESS, (Assert_Id)NULL);

    /* initialize module object state */
    Module.hostProcId = MultiProc_getId("HOST");
}


/*
 *  ======== Server_create ========
 */
Int Server_create()
{
    Int                 status = 0;
    MessageQ_Params     msgqParams;
    char                msgqName[32];

    /* enable some log events */
    Diags_setMask(MODULE_NAME"+EXF");

    /* create local message queue (inbound messages) */
    MessageQ_Params_init(&msgqParams);
    sprintf(msgqName, App_SlaveMsgQueName, MultiProc_getName(MultiProc_self()));
    Module.slaveQue = MessageQ_create(msgqName, &msgqParams);

    if (Module.slaveQue == NULL) {
        status = -1;
        goto leave;
    }

    Log_print0(Diags_INFO,"Server_create: server is ready");

    do {
        status = MessageQ_open(App_HostMsgQueName, &Module.hostQue);
        Task_sleep(10);
    } while (status == MessageQ_E_NOTFOUND);

    Log_print0(Diags_INFO, "Server_create: host queue opened");

leave:
    Log_print1(Diags_EXIT, "<-- Server_create: %d", (IArg)status);
    return (status);
}




/*
 *  ======== Server_exec ========
 */
Int Server_exec()
{
    Int                 status;
    Bool                running = TRUE;
    App_Msg *           msg;
    MessageQ_QueueId    queId;

    Log_print0(Diags_ENTRY | Diags_INFO, "--> Server_exec:");

    while (running) {

        /* wait for inbound message */
        status = MessageQ_get(Module.slaveQue, (MessageQ_Msg *)&msg,
            MessageQ_FOREVER);

        if (status < 0) {
            goto leave;
        }

        if (msg->cmd == App_CMD_SHUTDOWN) {
            running = FALSE;
        }

        /* process the message */
        Log_print1(Diags_INFO, "Server_exec: processed cmd=0x%x", msg->cmd);

        /* send message back */
        queId = MessageQ_getReplyQueue(msg); /* type-cast not needed */
        MessageQ_put(queId, (MessageQ_Msg)msg);
    } /* while (running) */

leave:
    Log_print1(Diags_EXIT, "<-- Server_exec: %d", (IArg)status);
    return(status);
}

/*
 *  ======== Server_delete ========
 */

Int Server_delete()
{
    Int         status;

    Log_print0(Diags_ENTRY, "--> Server_delete:");

    /* delete the video message queue */
    status = MessageQ_delete(&Module.slaveQue);

    if (status < 0) {
        goto leave;
    }

leave:
    if (status < 0) {
        Log_error1("Server_finish: error=0x%x", (IArg)status);
    }

    Log_print0(Diags_INFO, "closing host queue");
    status = MessageQ_close(&Module.hostQue);
    if (status < 0) {
        Log_print0(Diags_INFO, "host queue closing has error");
    }
    else {
        Log_print0(Diags_INFO, "hot queue closed");
    }


    /* disable log events */
    Log_print1(Diags_EXIT, "<-- Server_delete: %d", (IArg)status);
    Diags_setMask(MODULE_NAME"-EXF");

    return(status);
}

/*
 *  ======== Server_exit ========
 */

Void Server_exit(Void)
{
    /*
     * Note that there isn't a Registry_removeModule() yet:
     *     https://bugs.eclipse.org/bugs/show_bug.cgi?id=315448
     *
     * ... but this is where we'd call it.
     */
}

Jianzhong

Hi Jianzhongxu,

ex02_MessageQ
I tried out the ex02_messageq example and updated the server.c to your attached code.

I indeed see the "virtio_rpmsg_bus virtio0: msg received with no recipient", but it only occurs once in my dmesg output, but not constantly.

When I start the ARM application as "app_host DSP", the DSP is still unable to open the ARM queue.

In server.c the DSP is unable to move pass this while loop:

    Log_print0(Diags_INFO,"Server_create: server is ready");

    do {
        status = MessageQ_open(App_HostMsgQueName, &Module.hostQue);
        Task_sleep(10);
    } while (status == MessageQ_E_NOTFOUND);

    Log_print0(Diags_INFO, "Server_create: host queue opened");

    Log_print0(Diags_INFO,"Server_create: server is ready");
    
    do {
        // status = MessageQ_open(App_HostMsgQueName, &Module.hostQue);
        System_printf("Before Task_sleep()\n");
        Task_sleep(1);
        System_printf("After Task_sleep()\n");
    } while (status == MessageQ_E_NOTFOUND);

    Log_print0(Diags_INFO, "Server_create: host queue opened");

I am able to see the printf before the Task_sleep(1), but not after.
However, Task_sleep(0) seems to work... Any ideas why this is happening?

Modifications?
I have not modified anything in the ex02_messageq example except the server.c you attached and using 0xC6100000 for DDR instead of 0xC3100000 in the config.bld file.

Thanks & Regards,
Kim

Hi Kim,

To clarify, below is what I did to build and run the example:

- Build DSP RTOS lib:
      cd processor_sdk_rtos_omapl138_6_03_00_106/
      source ./setupenv.sh
      export TOOLS_INSTALL_PATH=~/ti
      export SDK_INSTALL_PATH=~/ti
      make ipc_bios

      Binaries at: ipc_3_50_04_08/packages/ti/ipc/tests/bin/ti_platforms_evmOMAPL138_DSP/
  
- Build ARM Linux lib:
      export PATH=~/ti/processor-sdk-linux-omapl138-lcdk-06.03.00.106/linux-devkit/sysroots/x86_64-arago-linux/usr/bin:$PATH
      export IPC_INSTALL_PATH=~/ti/ipc_3_50_04_08/
      export TI_RTOS_PATH=~/ti
      make ti-ipc-linux

      Binaries at: ipc_3_50_04_08/linux/src/tests

- Build the examples:
      make ti-ipc-linux-examples

      Binaries at:
         - Host: ipc_3_50_04_08/examples/OMAPL138_linux_elf/ex02_messageq/host/bin/release/app_host
         - DSP: ipc_3_50_04_08/examples/OMAPL138_linux_elf/ex02_messageq/dsp/bin/release/server_dsp.xe674

- Run the example on LCDK:
    tftp -g 192.168.1.235 -r app_host
    
    tftp -g 192.168.1.235 -r server_dsp.xe674
    
    ln -sfn /home/root/server_dsp.xe674 /lib/firmware/rproc-dsp-fw
    
    chmod +x app_host
    
    reboot the board
    
    ./app_host DSP

- Stop messages virtio_rpmsg_bus virtio0:
    dmesg -n 4

- Check DSP debug traces:
    mkdir /debug
    mount -t debugfs none /debug
    ./app_host DSP
    cat /debug/remoteproc/remoteproc0/trace0

Regards,

Jianzhong

Hi Jianzhongxu,

Thank you for the detailed clarification.

I managed to get an output similar to what you mentioned,.
 

 I also see the "virtio_rpmsg_bus" message constantly.


The problem was that SYS/BIOS was using timer1 because Clock.timerId = 1 was defined in the Dsp.cfg script.
I changed the applied timer to 3, then the ex02_MessageQ seems to run correctly on my board.

I am guessing that timer0 and timer1 are reserved for Linux, and timer2 & timer3 can be used for SYS/BIOS.

Thank you & Regards,
Kim

Hi Kim,

Glad that you have it working and thanks for sharing the information about timers. I'll close this thread. Please open a new one if you have further questions.

Regards,

Jianzhong