深入芯驰D9360核间通信案例，RPMSG关键技术深度剖析
本帖最后由 gztwdz4379 于 2025-9-10 10:30 编辑前言：
在多核异构架构成为工业SoC主流方案的当下，芯驰D9360凭借其Cortex-A55与Cortex-R5的协同设计，在需同时处理复杂应用与实时任务的场景中表现突出。本文将以眺望电子Core-D9360平台为例，详解如何利用RPMSG与VirtIO机制实现A核与R核间的可靠通信，并提供关键代码实现与调试方法。
图 1 Core-D9360 核心板
一、通信基础：RPMSG框架
RPMSG（Remote Processor Messaging）是Linux内核中用于处理器间通信的框架，采用virtio + rpmsg + IPCC三层架构实现：●virtio：提供虚拟化队列管理●rpmsg：实现消息封装与路由●IPCC：硬件中断控制器
在Core-D9360核心板中，A55核运行Linux，R5核运行RTOS，两者通过虚拟通道（VirtIO ring buffer）进行数据传输，支持双向、异步、多通道通信。
图 2核间通讯架构
二、核心代码实现
2.1 添加例程驱动RTOS系统的例程添加在SDK/source/ssdk/examples/kunlun/drivers下，分别创建Kconfig和rules.mk文件，其中Kconfig文件内容如下：
rules.mk文件内容如下：
返回上一层目录下，在Kconfig下添加talowe驱动模块的初始状态和图形界面类型，添加内容如下：
在rules.mk文件下，添加如下内容：
MODULES += $(LOCAL_DIR)/talowe: 如果配置选项 CONFIG_TALOWE_TEST为 "y"，则会将$(LOCAL_DIR)/talowe添加到变量MODULES中。当启用了"talowe test"功能时，会将$(LOCAL_DIR)/talowe模块添加到模块列表中。 2.2 R5核发送机制实现将rpmsg目录下的rpmsg_test.c文件复制到talowe.c文件中，该驱动描述如何通过RPMSG协议进行核间通信。我们可以在此程序基础上加入自己的协议。以下是R5核发送"Talowe:RtoA"字符串到A55核，并打印出接收到的信息的函数。<font color="#000000" face="微软雅黑" size="3">void send_receive_string(rpmsg_channel_t channel, const char *message) {
int max_payload;
struct dcf_ccm_hdr *snd_pkg;
struct dcf_ccm_hdr *rcv_pkg;
status_t ret;
max_payload = rpmsg_channel_max_payload(channel);
snd_pkg = osAlloc(max_payload);
rcv_pkg = osAlloc(max_payload);
ASSERT(snd_pkg && rcv_pkg);
memset(snd_pkg, 0x0, max_payload);
memset(rcv_pkg, 0x0, max_payload);
snd_pkg->dmsg.msg_type = COMM_MSG_CCM_ECHO;
snd_pkg->dmsg.opflags |= DCF_MSGF_TMS;
snd_pkg->dmsg.msg_len = sizeof(struct dcf_ccm_hdr) - sizeof(struct dcf_message);
strncpy(snd_pkg->data, message, max_payload - sizeof(struct dcf_ccm_hdr));
ret = rpmsg_channel_send(channel, RPMSG_ECHO_EPT_ADDR, snd_pkg, max_payload, 3000);
if (ret == RPMSG_SUCCESS) {
printf("Sent: %s\n", message);
} else {
printf("Failed to send message\n");
}
int received_len;
ret = rpmsg_channel_recv(channel, rcv_pkg, max_payload, &received_len, 3000);
if (ret == RPMSG_SUCCESS) {
printf("Received: %s\n", rcv_pkg->data);
} else {
printf("Failed to receive message\n");
}
osFree(snd_pkg);
osFree(rcv_pkg);
}</font>将以上函数添加至talowe.c文件内，并在主函数rpmsg_test编写调用该函数条件，如下： <font color="#000000" face="微软雅黑" size="3">const char* message_to_send = "Talowe:RtoA";
static int rpmsg_test(int argc, char *argv[])
{
int test_case = -1;
int type, rproc, times;
......
else if (!strcmp(argv, "perf")) {
test_case = 3;
type = atoi(argv);
rproc = atoi(argv);
times = atoi(argv);
}
else if(!strcmp(argv, "send")) {
test_case = 4;
type = atoi(argv);
rproc = atoi(argv);
times = atoi(argv);
}
else {
printf("Unknown cmd %s\n", argv);
goto exit;
}
......
......
case 3:
do_rpmsg_perf_test(channel, times);
break;
case 4:
send_receive_string(channel, message_to_send);
break;
default:
printf("Unknown case %d\n", test_case);
break;
}
</font> 加入串口打印提示：<font color="#000000" face="微软雅黑" size="3">static void rpmsg_test_show(void)
{
printf("\nList rpmsg communicate with remote:\n");
printf("\tType\t\t\tRemote-Proc\n");
......
......
printf("\trpmsg_test perf <type> <remote-proc> <times>\n");
printf("\trpmsg_test send <type> <remote-proc> <times>\n");
printf("\ne.g: test ping rpmsg.virtio 10 times with secure, use command:\n");
printf("\trpmsg_test ping 0 1 10\n");
}</font>编辑如下文件：SDK/source/ssdk/ middleware/rpmsg_service/rpmsg_echo.c<font color="#000000" face="微软雅黑" size="3">static int echo_channel_cb(void *data, int len, unsigned long src, void *arg)
{
rpmsg_channel_t chan = arg;
struct dcf_ccm_hdr *ccm_pkg = data;
const char *char_data = (char *)data;
int ret = 0;
if (ccm_pkg->dmsg.msg_type == COMM_MSG_CCM_ECHO) {
ccm_pkg->time = timer_get_current_time(g_syscnt_timer) * g_sdrv_syscnt_dev.cnt_per_us;
ret = rpmsg_channel_send(chan, src, data, len, 1000);
printf("Sending data (length %d): ", len);
for (int i = 8; i < len; i++) {
printf("%c ", char_data);
}
printf("\n");
}
else if (ccm_pkg->dmsg.msg_type == COMM_MSG_CCM_ACK) {
ret = rpmsg_channel_send(chan, src, (char *)"ACK", 4, 1000);
ssdk_printf(SSDK_INFO,"send ACK\n");
}
else {
ssdk_printf(SSDK_WARNING, "echo_channel_cb: unknown %d bytes from addr %ld\n", len, src);
}
if (ret != 0) {
ssdk_printf(SSDK_WARNING, "echo_channel_cb: channel send failed\n");
}
return ret;
}</font>
通过以下指令打开图形化配置界面，进入到Driver and Application Examples->Driver Example Support下，可以看到我们新加的talowe test Support驱动配置选项，需要关闭 RPMSG Example Application Support 选项，如下：
<font color="#000000" face="微软雅黑" size="3">./tools/menuconfig.sh -b d9360_ref -p ref -c secure</font>
2.3 A55核发送数据到R5核A55核Linux系统通过echo_test命令与R5核进行通讯，以下是该命令源码的文件位置：
自定义一个发送和接收字符串的函数，如下：<font color="#000000" face="微软雅黑" size="3">
int send_receive_string(int fd, const char *send_str,int ntimes, int seconds) {
int i = 0, j = 0;
int size, bytes_rcvd, bytes_sent;
long elapse = 0;
err_cnt = 0;
i_payload = (struct _payload *)malloc(sizeof(struct _payload) + payload_max_size);
r_payload = (struct _payload *)malloc(sizeof(struct _payload) + payload_max_size);
if (i_payload == 0 || r_payload == 0) {
printf("ERROR: Failed to allocate memory for payload.\n");
return -1;
}
if (seconds)
gettimeofday(&start_test, NULL);
i_payload->magic = 0xA5;
for (j = 0; j < ntimes; j++) {
i_payload->num = i;
i_payload->size = size;
strcpy(i_payload->data, send_str);
if (verbose)
printf("\r\n sending payload number");
if (verbose)
printf(" %d of size %lu\r\n", i_payload->num, (sizeof(struct _payload)) + strlen(i_payload->data));
bytes_sent = write(fd, i_payload, sizeof(struct _payload) + strlen(i_payload->data));
if (bytes_sent <= 0) {
if (verbose) {
perror("\r\n Error sending data\n");
break;
} else
fprintf(stderr, "#");
err_cnt++;
continue;
}
printf("send string:%s\n",i_payload->data);
r_payload->num = 0;
bytes_rcvd = read(fd, r_payload, sizeof(struct _payload) + payload_max_size);
while (bytes_rcvd <= 0) {
usleep(10000);
bytes_rcvd = read(fd, r_payload, sizeof(struct _payload) + payload_max_size);
}
r_payload->data = '\0';
printf("receive string:%s\n",r_payload->data);
if (interval)
sleep(interval);
}
free(i_payload);
free(r_payload);
return 0;
}</font>在main函数内添加新增函数条件，执行指令时实现A55核发送"Talowe:AtoR"字符串到R5核：<font color="#000000" face="微软雅黑" size="3">
int main(int argc, char *argv[])
{
int opt;
char *rpmsg_dev = RPMSG_DEVICE_NAME;
......
int test_second = 0;
int send_char = 0;
char *value_c;
if (strstr(argv, "property")) {
do_property_test(argc, argv);
return 0;
}
......
while ((opt = getopt(argc, argv, "a:d:n:cbpxvst:hi:lm:S:P:")) != -1) {
switch (opt) {
......
case 'v':
verbose = 1;
break;
case 'c':
send_char = 1;
break;
case 'b':
benchmark = 1;
break;
......
default:
printf("getopt return unsupported option: -%c\n", opt);
usage("echo_test");
break;
}
}
else if (benchmark == 2) {
iperf_test(fd, ntimes);
} else if (benchmark == 3) {
throughput_test(fd, ntimes, test_second);
} else if( send_char == 1){
const char *message_to_send = "Talowe:AtoR";
int result = send_receive_string(fd, message_to_send,ntimes, test_second);
if (result < 0) {
printf("Error sending/receiving string.\n");
}
}
else {
if (test_second) {
ntimes = 0x7fffffff;
}
......
return 0;
}
在打印列表添加如下提示：
static void usage(const char *cmd)
{
printf("This is s rpmsg echo test %s, MTU=%d\n", ECHO_TEST_VERSION, rpmsg_payload_test);
......
printf("%s -v\t\t: Verbose mode\n", cmd);
printf("%s -c \t: send Talowe:AtoR\n", cmd);
......
printf("echo_test -d soc:ipcc@0.ipcc-echo.-1.30 -x -t 10 ; Throughput test in average (Ack'd) in 10 seconds (print in 1 second)\n");
exit(0);
}</font>编辑如下文件：SDK/source/linux/drivers/rpmsg/virtio_rpmsg_bus.c<font color="#000000" face="微软雅黑" size="3">static int rpmsg_echo_cb(struct rpmsg_device *rpdev, void *data, int len,
void *priv, u32 src)
{
struct dcf_message *msg = data;
struct virtproc_info *vrp = priv;
......
switch (msg->msg_type) {
case COMM_MSG_CCM_ECHO:
dev_err(dev,"virtio send susses");
/* Add timestamp in the time */
......
break;
case COMM_MSG_CCM_ACK:
dev_err(dev,"rpmsg recv ACK");
err = __send_offchannel_raw(vrp, RPMSG_ECHO_ADDR, src, "ACK", 4, true);
......
break;
default:
/* No more action, just drop the packet */
break;
}
return 0;
}</font>编辑如下文件：SDK/source/linux/drivers/rpmsg/semidrive_ipcc.c<font color="#000000" face="微软雅黑" size="3">
static int rpmsg_ipcc_echo_cb(struct rpmsg_device *rpdev, void *data, int len,
void *priv, u32 src)
{
struct rpmsg_ipcc_device *vrp = priv;
struct device *dev = vrp->dev;
......
switch (dmsg->msg_type) {
case COMM_MSG_CCM_ECHO:
dev_err(dev,"ipcc send susses");
/* Add timestamp in the time */
......
break;
case COMM_MSG_CCM_ACK:
dev_err(dev,"ipcc recv ACK");
err = __send_offchannel_raw(vrp, RPMSG_ECHO_ADDR, src, "ACK", 4,true);
......
break;
default:
/* No more action, just drop the packet */
break;
}
return 0;
}</font>
内核需打开以下配置：<font color="#000000" face="微软雅黑" size="3">CONFIG_RPMSG=y
CONFIG_RPMSG_CHAR=y
CONFIG_RPMSG_VIRTIO=y
CONFIG_RPMSG_SEMIDRIVE=y</font>
三、烧写测试验证
3.1 R5核向A55核发送信息以下测试内容为R5核发送"Talowe:RtoA"字符串到A55核，A55核接收到字符串之后重新发送给R5核。R5核：<font color="#000000" face="微软雅黑" size="3">rpmsg_test send 0 3 1</font>
A55核：
3.2 A55核向R5发送信息以下测试内容为A55核发送"Talowe:AtoR"字符串到R5核，R5核接收到字符串之后重新发送给A55核。A55核：<font color="#000000" face="微软雅黑" size="3">echo_test -d virtio0.rpmsg-echo.-1.30 -c 1</font>
R5核：
四、结语
通过RPMsg在单芯片上实现了这种高效的核间通信机制，使得异构多核SoC能够真正发挥"实时控制+高性能计算"的协同优势，成为工业4.0、自动驾驶、AIoT等领域的核心技术底座。广州眺望电子科技有限公司推出Core-D9360核心板与EVM-D9载板外，还提供完整的SDK、编译指南、测试手册及技术文档，覆盖从环境搭建、代码编译、镜像烧写到功能验证的全流程，助力开发者快速实现产品化。如果您希望获取完整核心板开发资料与产品价格，欢迎关注我们的公众号或官方淘宝店铺，联系获取！
这个方案一般应用在哪儿？什么场景啊？
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