@@ -117,6 +117,46 @@ fail:
return NULL;
}
+/**
+ * load_device_tree_from_sysfs
+ *
+ * extract the dt blob from host sysfs
+ * this has a runtime dependency on the dtc binary
+ */
+void *load_device_tree_from_sysfs(void)
+{
+ char cmd[] = "dtc -I fs -O dtb /sys/firmware/devicetree/base";
+ FILE *pipe;
+ void *fdt;
+ int ret, actual_dt_size;
+
+ pipe = popen(cmd, "r");
+ if (!pipe) {
+ error_report("%s: Error when executing dtc", __func__);
+ return NULL;
+ }
+ fdt = g_malloc0(FDT_MAX_SIZE);
+ actual_dt_size = fread(fdt, 1, FDT_MAX_SIZE, pipe);
+ pclose(pipe);
+
+ if (actual_dt_size == 0) {
+ error_report("%s: could not copy host device tree in memory: %m",
+ __func__);
+ goto fail;
+ }
+ ret = fdt_check_header(fdt);
+ if (ret) {
+ error_report("%s: Host dt file loaded into memory is invalid: %s",
+ __func__, fdt_strerror(ret));
+ goto fail;
+ }
+ return fdt;
+
+fail:
+ g_free(fdt);
+ return NULL;
+}
+
static int findnode_nofail(void *fdt, const char *node_path)
{
int offset;
@@ -16,6 +16,7 @@
void *create_device_tree(int *sizep);
void *load_device_tree(const char *filename_path, int *sizep);
+void *load_device_tree_from_sysfs(void);
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 (/sys/firmware/devicetree/base). This has a runtime dependency on the dtc binary. This functionality is useful for platform device passthrough where the host device tree needs to be parsed to feed information into the guest device tree. Signed-off-by: Eric Auger <eric.auger@linaro.org> --- device_tree.c | 40 ++++++++++++++++++++++++++++++++++++++++ include/sysemu/device_tree.h | 1 + 2 files changed, 41 insertions(+)