[v1.03][RISCV] Add basic SoC detection backend

src/riscv/udev.c

@@ -0,0 +1,44 @@
+#include <errno.h>
+#include <string.h>
+
+#include "../common/global.h"
+#include "udev.h"
+
+#define _PATH_DEVTREE "/proc/device-tree/compatible"
+#define DEVTREE_HARDWARE_FIELD 3
+
+// TODO: Works only for DEVTREE_FIELD == DEVTREE_HARDWARE_FIELD
+char* get_field_from_devtree(int DEVTREE_FIELD) {
+  int filelen;
+  char* buf;
+  if((buf = read_file(_PATH_DEVTREE, &filelen)) == NULL) {
+    printWarn("read_file: %s: %s:\n", _PATH_DEVTREE, strerror(errno));
+    return NULL;
+  }
+
+  // Here we would use strstr to find the comma
+  // However, the device-tree file may contain NULL
+  // bytes in the middle of the string, which would
+  // cause strstr to return NULL even when there might
+  // be an occurence after the NULL byte
+  int i=0;
+  char* tmp1 = buf;
+  do {
+    tmp1++;
+    if(*tmp1 == ',') i++;
+  } while(filelen > (tmp1-buf) && i < DEVTREE_FIELD);
+
+  tmp1++;
+  if((tmp1-buf) >= filelen) return NULL;
+
+  int strlen = filelen-(tmp1-buf);
+  char* hardware = emalloc(sizeof(char) * strlen);
+  memset(hardware, 0, sizeof(char) * strlen);
+  strncpy(hardware, tmp1, strlen-1);
+
+  return hardware;
+}
+
+char* get_hardware_from_devtree(void) {
+  return get_field_from_devtree(DEVTREE_HARDWARE_FIELD);
+}