portable device access api based on unix file descriptors

bsp_linux/hardware/hardware.c

@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include <hardware/interfaces.h>
+
+extern const char *device_root;
+
+int hw_device_open(const char *path, size_t path_len) {
+  int sock;
+  if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
+    perror(NULL);
+    exit(-1);
+  }
+  struct sockaddr_un address;
+  address.sun_family = AF_UNIX;
+  snprintf(address.sun_path, sizeof(address.sun_path), "%s%.*s", device_root,
+           path_len, path);
+  if (connect(sock, (struct sockaddr *)&address, sizeof(address)) != 0) {
+    perror(NULL);
+    exit(-1);
+  }
+  return sock;
+}