arch/arm/boot/compressed/atags_to_fdt.c

   1 #include <asm/setup.h>
   2 #include <libfdt.h>
   3
   4 static int node_offset(void *fdt, const char *node_path)
   5 {
   6         int offset = fdt_path_offset(fdt, node_path);
   7         if (offset == -FDT_ERR_NOTFOUND)
   8                 offset = fdt_add_subnode(fdt, 0, node_path);
   9         return offset;
  10 }
  11
  12 static int setprop(void *fdt, const char *node_path, const char *property,
  13                    uint32_t *val_array, int size)
  14 {
  15         int offset = node_offset(fdt, node_path);
  16         if (offset < 0)
  17                 return offset;
  18         return fdt_setprop(fdt, offset, property, val_array, size);
  19 }
  20
  21 static int setprop_string(void *fdt, const char *node_path,
  22                           const char *property, const char *string)
  23 {
  24         int offset = node_offset(fdt, node_path);
  25         if (offset < 0)
  26                 return offset;
  27         return fdt_setprop_string(fdt, offset, property, string);
  28 }
  29
  30 static int setprop_cell(void *fdt, const char *node_path,
  31                         const char *property, uint32_t val)
  32 {
  33         int offset = node_offset(fdt, node_path);
  34         if (offset < 0)
  35                 return offset;
  36         return fdt_setprop_cell(fdt, offset, property, val);
  37 }
  38
  39 /*
  40  * Convert and fold provided ATAGs into the provided FDT.
  41  *
  42  * REturn values:
  43  *    = 0 -> pretend success
  44  *    = 1 -> bad ATAG (may retry with another possible ATAG pointer)
  45  *    < 0 -> error from libfdt
  46  */
  47 int atags_to_fdt(void *atag_list, void *fdt, int total_space)
  48 {
  49         struct tag *atag = atag_list;
  50         uint32_t mem_reg_property[2 * NR_BANKS];
  51         int memcount = 0;
  52         int ret;
  53
  54         /* make sure we've got an aligned pointer */
  55         if ((u32)atag_list & 0x3)
  56                 return 1;
  57
  58         /* if we get a DTB here we're done already */
  59         if (*(u32 *)atag_list == fdt32_to_cpu(FDT_MAGIC))
  60                return 0;
  61
  62         /* validate the ATAG */
  63         if (atag->hdr.tag != ATAG_CORE ||
  64             (atag->hdr.size != tag_size(tag_core) &&
  65              atag->hdr.size != 2))
  66                 return 1;
  67
  68         /* let's give it all the room it could need */
  69         ret = fdt_open_into(fdt, fdt, total_space);
  70         if (ret < 0)
  71                 return ret;
  72
  73         for_each_tag(atag, atag_list) {
  74                 if (atag->hdr.tag == ATAG_CMDLINE) {
  75                         setprop_string(fdt, "/chosen", "bootargs",
  76                                         atag->u.cmdline.cmdline);
  77                 } else if (atag->hdr.tag == ATAG_MEM) {
  78                         if (memcount >= sizeof(mem_reg_property)/4)
  79                                 continue;
  80                         if (!atag->u.mem.size)
  81                                 continue;
  82                         mem_reg_property[memcount++] = cpu_to_fdt32(atag->u.mem.start);
  83                         mem_reg_property[memcount++] = cpu_to_fdt32(atag->u.mem.size);
  84                 } else if (atag->hdr.tag == ATAG_INITRD2) {
  85                         uint32_t initrd_start, initrd_size;
  86                         initrd_start = atag->u.initrd.start;
  87                         initrd_size = atag->u.initrd.size;
  88                         setprop_cell(fdt, "/chosen", "linux,initrd-start",
  89                                         initrd_start);
  90                         setprop_cell(fdt, "/chosen", "linux,initrd-end",
  91                                         initrd_start + initrd_size);
  92                 }
  93         }
  94
  95         if (memcount)
  96                 setprop(fdt, "/memory", "reg", mem_reg_property, 4*memcount);
  97
  98         return fdt_pack(fdt);
  99 }