device_tree.c

   1 /*
   2  * Functions to help device tree manipulation using libfdt.
   3  * It also provides functions to read entries from device tree proc
   4  * interface.
   5  *
   6  * Copyright 2008 IBM Corporation.
   7  * Authors: Jerone Young <jyoung5@us.ibm.com>
   8  *          Hollis Blanchard <hollisb@us.ibm.com>
   9  *
  10  * This work is licensed under the GNU GPL license version 2 or later.
  11  *
  12  */
  13
  14 #include <stdio.h>
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <fcntl.h>
  18 #include <unistd.h>
  19 #include <stdlib.h>
  20
  21 #include "config.h"
  22 #include "qemu-common.h"
  23 #include "sysemu.h"
  24 #include "device_tree.h"
  25
  26 #include <libfdt.h>
  27
  28 void *load_device_tree(const char *filename_path, int *sizep)
  29 {
  30     int dt_size;
  31     int dt_file_load_size;
  32     int ret;
  33     void *fdt = NULL;
  34
  35     *sizep = 0;
  36     dt_size = get_image_size(filename_path);
  37     if (dt_size < 0) {
  38         printf("Unable to get size of device tree file '%s'\n",
  39             filename_path);
  40         goto fail;
  41     }
  42
  43     /* Expand to 2x size to give enough room for manipulation.  */
  44     dt_size *= 2;
  45     /* First allocate space in qemu for device tree */
  46     fdt = qemu_mallocz(dt_size);
  47
  48     dt_file_load_size = load_image(filename_path, fdt);
  49     if (dt_file_load_size < 0) {
  50         printf("Unable to open device tree file '%s'\n",
  51                filename_path);
  52         goto fail;
  53     }
  54
  55     ret = fdt_open_into(fdt, fdt, dt_size);
  56     if (ret) {
  57         printf("Unable to copy device tree in memory\n");
  58         goto fail;
  59     }
  60
  61     /* Check sanity of device tree */
  62     if (fdt_check_header(fdt)) {
  63         printf ("Device tree file loaded into memory is invalid: %s\n",
  64             filename_path);
  65         goto fail;
  66     }
  67     *sizep = dt_size;
  68     return fdt;
  69
  70 fail:
  71     qemu_free(fdt);
  72     return NULL;
  73 }
  74
  75 int qemu_devtree_setprop(void *fdt, const char *node_path,
  76                          const char *property, uint32_t *val_array, int size)
  77 {
  78     int offset;
  79
  80     offset = fdt_path_offset(fdt, node_path);
  81     if (offset < 0)
  82         return offset;
  83
  84     return fdt_setprop(fdt, offset, property, val_array, size);
  85 }
  86
  87 int qemu_devtree_setprop_cell(void *fdt, const char *node_path,
  88                               const char *property, uint32_t val)
  89 {
  90     int offset;
  91
  92     offset = fdt_path_offset(fdt, node_path);
  93     if (offset < 0)
  94         return offset;
  95
  96     return fdt_setprop_cell(fdt, offset, property, val);
  97 }
  98
  99 int qemu_devtree_setprop_string(void *fdt, const char *node_path,
 100                                 const char *property, const char *string)
 101 {
 102     int offset;
 103
 104     offset = fdt_path_offset(fdt, node_path);
 105     if (offset < 0)
 106         return offset;
 107
 108     return fdt_setprop_string(fdt, offset, property, string);
 109 }