Memory-mapped process data.

lib/common.c

@@ -39,6 +39,7 @@
 #include <errno.h>
 #include <string.h>
 #include <sys/ioctl.h>
+#include <sys/mman.h>
 
 #include "master.h"
 #include "master/ioctl.h"
@@ -65,6 +66,9 @@ ec_master_t *ecrt_request_master(unsigned int master_index)
         return 0;
     }
 
+    master->process_data = NULL;
+    master->process_data_size = 0;
+
     snprintf(path, MAX_PATH_LEN - 1, "/dev/EtherCAT%u", master_index);
 
     master->fd = open(path, O_RDWR);
@@ -89,6 +93,10 @@ ec_master_t *ecrt_request_master(unsigned int master_index)
 
 void ecrt_release_master(ec_master_t *master)
 {
+    if (master->process_data)  {
+        munmap(master->process_data, master->process_data_size);
+    }
+
     close(master->fd);
     free(master);
 }

lib/domain.c

@@ -38,7 +38,15 @@
 
 /*****************************************************************************/
 
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
 #include "domain.h"
+#include "master.h"
+#include "master/ioctl.h"
 
 /*****************************************************************************/
 
@@ -68,19 +76,43 @@ int ecrt_domain_reg_pdo_entry_list(ec_domain_t *domain,
 
 uint8_t *ecrt_domain_data(ec_domain_t *domain)
 {
-    return 0;
+    if (!domain->process_data) {
+        int offset = 0;
+
+        offset = ioctl(domain->master->fd, EC_IOCTL_DOMAIN_OFFSET,
+                domain->index);
+        if (offset == -1) {
+            fprintf(stderr, "Failed to get domain offset: %s\n",
+                    strerror(errno));
+            return NULL; 
+        }
+    
+        domain->process_data = domain->master->process_data + offset;
+    }
+
+    return domain->process_data;
 }
 
 /*****************************************************************************/
 
 void ecrt_domain_process(ec_domain_t *domain)
 {
+    if (ioctl(domain->master->fd, EC_IOCTL_DOMAIN_PROCESS,
+                domain->index) == -1) {
+        fprintf(stderr, "Failed to process domain offset: %s\n",
+                strerror(errno));
+    }
 }
 
 /*****************************************************************************/
 
 void ecrt_domain_queue(ec_domain_t *domain)
 {
+    if (ioctl(domain->master->fd, EC_IOCTL_DOMAIN_QUEUE,
+                domain->index) == -1) {
+        fprintf(stderr, "Failed to queue domain offset: %s\n",
+                strerror(errno));
+    }
 }
 
 /*****************************************************************************/

lib/domain.h

@@ -38,6 +38,7 @@
 struct ec_domain {
     unsigned int index;
     ec_master_t *master;
+    uint8_t *process_data;
 };
 
 /*****************************************************************************/

lib/master.c

@@ -36,6 +36,7 @@
 #include <stdio.h>
 #include <errno.h>
 #include <string.h>
+#include <sys/mman.h>
 
 #include "master.h"
 #include "domain.h"
@@ -64,6 +65,7 @@ ec_domain_t *ecrt_master_create_domain(ec_master_t *master)
 
     domain->index = (unsigned int) index;
     domain->master = master;
+    domain->process_data = NULL;
     return domain;
 }
 
@@ -106,12 +108,27 @@ ec_slave_config_t *ecrt_master_slave_config(ec_master_t *master,
 
 int ecrt_master_activate(ec_master_t *master)
 {
-    if (ioctl(master->fd, EC_IOCTL_ACTIVATE, NULL) == -1) {
+    if (ioctl(master->fd, EC_IOCTL_ACTIVATE,
+                &master->process_data_size) == -1) {
         fprintf(stderr, "Failed to activate master: %s\n",
                 strerror(errno));
         return -1; 
     }
 
+    if (master->process_data_size) {
+        master->process_data = mmap(0, master->process_data_size,
+                PROT_READ | PROT_WRITE, MAP_PRIVATE, master->fd, 0);
+        if (master->process_data == MAP_FAILED) {
+            fprintf(stderr, "Failed to map process data: %s", strerror(errno));
+            master->process_data = NULL;
+            master->process_data_size = 0;
+            return -1;
+        }
+
+        // Access the mapped region to cause the initial page fault
+        printf("pd: %x\n", master->process_data[0]);
+    }
+
     return 0;
 }
 

lib/master.h

@@ -37,6 +37,8 @@
 
 struct ec_master {
     int fd;
+    uint8_t *process_data;
+    size_t process_data_size;
 };
 
 /*****************************************************************************/