@@ -17,6 +17,9 @@
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
+#ifdef CONFIG_LINUX
+#include <dirent.h>
+#endif
#include "qemu-common.h"
#include "qemu/error-report.h"
@@ -117,6 +120,103 @@ fail:
return NULL;
}
+#ifdef CONFIG_LINUX
+
+#define SYSFS_DT_BASEDIR "/proc/device-tree"
+
+/**
+ * read_fstree: this function is inspired from dtc read_fstree
+ * @fdt: preallocated fdt blob buffer, to be populated
+ * @dirname: directory to scan under SYSFS_DT_BASEDIR
+ * the search is recursive and the tree is searched down to the
+ * leafs (property files).
+ *
+ * the function self-asserts in case of error
+ */
+static void read_fstree(void *fdt, const char *dirname)
+{
+ DIR *d;
+ struct dirent *de;
+ struct stat st;
+ const char *root_dir = SYSFS_DT_BASEDIR;
+ char *parent_node;
+
+ if (strstr(dirname, root_dir) != dirname) {
+ error_report("%s: %s must be searched within %s",
+ __func__, dirname, root_dir);
+ exit(1);
+ }
+ parent_node = (char *)&dirname[strlen(SYSFS_DT_BASEDIR)];
+
+ d = opendir(dirname);
+ if (!d) {
+ error_setg(&error_fatal, "%s cannot open %s", __func__, dirname);
+ }
+
+ while ((de = readdir(d)) != NULL) {
+ char *tmpnam;
+
+ if (!g_strcmp0(de->d_name, ".")
+ || !g_strcmp0(de->d_name, "..")) {
+ continue;
+ }
+
+ tmpnam = g_strjoin("/", dirname, de->d_name, NULL);
+
+ if (lstat(tmpnam, &st) < 0) {
+ error_setg(&error_fatal, "%s cannot lstat %s", __func__, tmpnam);
+ }
+
+ if (S_ISREG(st.st_mode)) {
+ gchar *val;
+ gsize len;
+
+ if (!g_file_get_contents(tmpnam, &val, &len, NULL)) {
+ error_setg(&error_fatal, "%s not able to extract info from %s",
+ __func__, tmpnam);
+ }
+
+ if (strlen(parent_node) > 0) {
+ qemu_fdt_setprop(fdt, parent_node,
+ de->d_name, val, len);
+ } else {
+ qemu_fdt_setprop(fdt, "/", de->d_name, val, len);
+ }
+ g_free(val);
+ } else if (S_ISDIR(st.st_mode)) {
+ char *node_name;
+
+ node_name = g_strdup_printf("%s/%s",
+ parent_node, de->d_name);
+ qemu_fdt_add_subnode(fdt, node_name);
+ g_free(node_name);
+ read_fstree(fdt, tmpnam);
+ }
+
+ g_free(tmpnam);
+ }
+
+ closedir(d);
+}
+
+/* load_device_tree_from_sysfs: extract the dt blob from host sysfs */
+void *load_device_tree_from_sysfs(void)
+{
+ void *host_fdt;
+ int host_fdt_size;
+
+ host_fdt = create_device_tree(&host_fdt_size);
+ read_fstree(host_fdt, SYSFS_DT_BASEDIR);
+ if (fdt_check_header(host_fdt)) {
+ error_setg(&error_fatal,
+ "%s host device tree extracted into memory is invalid",
+ __func__);
+ }
+ return host_fdt;
+}
+
+#endif /* CONFIG_LINUX */
+
static int findnode_nofail(void *fdt, const char *node_path)
{
int offset;
@@ -16,6 +16,9 @@
void *create_device_tree(int *sizep);
void *load_device_tree(const char *filename_path, int *sizep);
+#ifdef CONFIG_LINUX
+void *load_device_tree_from_sysfs(void);
+#endif
int qemu_fdt_setprop(void *fdt, const char *node_path,
const char *property, const void *val, int size);
This function returns the host device tree blob from sysfs (/proc/device-tree). It uses a recursive function inspired from dtc read_fstree. Signed-off-by: Eric Auger <eric.auger@linaro.org> --- v1 -> v2: - do not implement/expose read_fstree and load_device_tree_from_sysfs if CONFIG_LINUX is not defined (lstat is not implemeted in mingw) - correct indentation in read_fstree - use /proc/device-tree symlink instead of /sys/firmware/devicetree/base path (kernel.org/doc/Documentation/ABI/testing/sysfs-firmware-ofw) - use g_file_get_contents in read_fstree - introduce SYSFS_DT_BASEDIR macro and use strlen - exit on error in load_device_tree_from_sysfs - user error_setg RFC -> v1: - remove runtime dependency on dtc binary and introduce read_fstree --- device_tree.c | 100 +++++++++++++++++++++++++++++++++++++++++++ include/sysemu/device_tree.h | 3 ++ 2 files changed, 103 insertions(+) -- 1.9.1