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 new_dt_size;
  33     int ret;
  34     void *fdt = NULL;
  35
  36     *sizep = 0;
  37     dt_size = get_image_size(filename_path);
  38     if (dt_size < 0) {
  39         printf("Unable to get size of device tree file '%s'\n",
  40             filename_path);
  41         goto fail;
  42     }
  43
  44     /* Expand to 2x size to give enough room for manipulation.  */
  45     dt_size *= 2;
  46     /* First allocate space in qemu for device tree */
  47     fdt = qemu_mallocz(dt_size);
  48
  49     dt_file_load_size = load_image(filename_path, fdt);
  50     if (dt_file_load_size < 0) {
  51         printf("Unable to open device tree file '%s'\n",
  52                filename_path);
  53         goto fail;
  54     }
  55
  56     ret = fdt_open_into(fdt, fdt, dt_size);
  57     if (ret) {
  58         printf("Unable to copy device tree in memory\n");
  59         goto fail;
  60     }
  61
  62     /* Check sanity of device tree */
  63     if (fdt_check_header(fdt)) {
  64         printf ("Device tree file loaded into memory is invalid: %s\n",
  65             filename_path);
  66         goto fail;
  67     }
  68     *sizep = dt_size;
  69     return fdt;
  70
  71 fail:
  72     qemu_free(fdt);
  73     return NULL;
  74 }
  75
  76 int qemu_devtree_setprop(void *fdt, const char *node_path,
  77                          const char *property, uint32_t *val_array, int size)
  78 {
  79     int offset;
  80
  81     offset = fdt_path_offset(fdt, node_path);
  82     if (offset < 0)
  83         return offset;
  84
  85     return fdt_setprop(fdt, offset, property, val_array, size);
  86 }
  87
  88 int qemu_devtree_setprop_cell(void *fdt, const char *node_path,
  89                               const char *property, uint32_t val)
  90 {
  91     int offset;
  92
  93     offset = fdt_path_offset(fdt, node_path);
  94     if (offset < 0)
  95         return offset;
  96
  97     return fdt_setprop_cell(fdt, offset, property, val);
  98 }
  99
 100 int qemu_devtree_setprop_string(void *fdt, const char *node_path,
 101                                 const char *property, const char *string)
 102 {
 103     int offset;
 104
 105     offset = fdt_path_offset(fdt, node_path);
 106     if (offset < 0)
 107         return offset;
 108
 109     return fdt_setprop_string(fdt, offset, property, string);
 110 }