qemu/device_tree.c

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/*
* Functions to help device tree manipulation using libfdt.
* It also provides functions to read entries from device tree proc
* interface.
*
* Copyright 2008 IBM Corporation.
* Authors: Jerone Young <jyoung5@us.ibm.com>
* Hollis Blanchard <hollisb@us.ibm.com>
*
* This work is licensed under the GNU GPL license version 2 or later.
*
*/
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include "config.h"
#include "qemu-common.h"
#include "device_tree.h"
#include "hw/loader.h"
#include <libfdt.h>
void *load_device_tree(const char *filename_path, int *sizep)
{
int dt_size;
int dt_file_load_size;
int ret;
void *fdt = NULL;
*sizep = 0;
dt_size = get_image_size(filename_path);
if (dt_size < 0) {
printf("Unable to get size of device tree file '%s'\n",
filename_path);
goto fail;
}
/* Expand to 2x size to give enough room for manipulation. */
dt_size += 10000;
dt_size *= 2;
/* First allocate space in qemu for device tree */
fdt = g_malloc0(dt_size);
dt_file_load_size = load_image(filename_path, fdt);
if (dt_file_load_size < 0) {
printf("Unable to open device tree file '%s'\n",
filename_path);
goto fail;
}
ret = fdt_open_into(fdt, fdt, dt_size);
if (ret) {
printf("Unable to copy device tree in memory\n");
goto fail;
}
/* Check sanity of device tree */
if (fdt_check_header(fdt)) {
printf ("Device tree file loaded into memory is invalid: %s\n",
filename_path);
goto fail;
}
*sizep = dt_size;
return fdt;
fail:
g_free(fdt);
return NULL;
}
static int findnode_nofail(void *fdt, const char *node_path)
{
int offset;
offset = fdt_path_offset(fdt, node_path);
if (offset < 0) {
fprintf(stderr, "%s Couldn't find node %s: %s\n", __func__, node_path,
fdt_strerror(offset));
exit(1);
}
return offset;
}
int qemu_devtree_setprop(void *fdt, const char *node_path,
const char *property, void *val_array, int size)
{
int r;
r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val_array, size);
if (r < 0) {
fprintf(stderr, "%s: Couldn't set %s/%s: %s\n", __func__, node_path,
property, fdt_strerror(r));
exit(1);
}
return r;
}
int qemu_devtree_setprop_cell(void *fdt, const char *node_path,
const char *property, uint32_t val)
{
int r;
r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
if (r < 0) {
fprintf(stderr, "%s: Couldn't set %s/%s = %#08x: %s\n", __func__,
node_path, property, val, fdt_strerror(r));
exit(1);
}
return r;
}
int qemu_devtree_setprop_string(void *fdt, const char *node_path,
const char *property, const char *string)
{
int r;
r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
if (r < 0) {
fprintf(stderr, "%s: Couldn't set %s/%s = %s: %s\n", __func__,
node_path, property, string, fdt_strerror(r));
exit(1);
}
return r;
}
int qemu_devtree_nop_node(void *fdt, const char *node_path)
{
int r;
r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
if (r < 0) {
fprintf(stderr, "%s: Couldn't nop node %s: %s\n", __func__, node_path,
fdt_strerror(r));
exit(1);
}
return r;
}
int qemu_devtree_add_subnode(void *fdt, const char *name)
{
char *dupname = g_strdup(name);
char *basename = strrchr(dupname, '/');
int retval;
if (!basename) {
g_free(dupname);
return -1;
}
basename[0] = '\0';
basename++;
retval = fdt_add_subnode(fdt, findnode_nofail(fdt, dupname), basename);
if (retval < 0) {
fprintf(stderr, "FDT: Failed to create subnode %s: %s\n", name,
fdt_strerror(retval));
exit(1);
}
g_free(dupname);
return retval;
}