of_fdt.h 2.6 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172
  1. /*
  2. * Definitions for working with the Flattened Device Tree data format
  3. *
  4. * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
  5. * benh@kernel.crashing.org
  6. *
  7. * This program is free software; you can redistribute it and/or
  8. * modify it under the terms of the GNU General Public License
  9. * version 2 as published by the Free Software Foundation.
  10. */
  11. #ifndef _LINUX_OF_FDT_H
  12. #define _LINUX_OF_FDT_H
  13. #include <linux/types.h>
  14. #include <linux/init.h>
  15. /* Definitions used by the flattened device tree */
  16. #define OF_DT_HEADER 0xd00dfeed /* marker */
  17. #define OF_DT_BEGIN_NODE 0x1 /* Start of node, full name */
  18. #define OF_DT_END_NODE 0x2 /* End node */
  19. #define OF_DT_PROP 0x3 /* Property: name off, size,
  20. * content */
  21. #define OF_DT_NOP 0x4 /* nop */
  22. #define OF_DT_END 0x9
  23. #define OF_DT_VERSION 0x10
  24. #ifndef __ASSEMBLY__
  25. /*
  26. * This is what gets passed to the kernel by prom_init or kexec
  27. *
  28. * The dt struct contains the device tree structure, full pathes and
  29. * property contents. The dt strings contain a separate block with just
  30. * the strings for the property names, and is fully page aligned and
  31. * self contained in a page, so that it can be kept around by the kernel,
  32. * each property name appears only once in this page (cheap compression)
  33. *
  34. * the mem_rsvmap contains a map of reserved ranges of physical memory,
  35. * passing it here instead of in the device-tree itself greatly simplifies
  36. * the job of everybody. It's just a list of u64 pairs (base/size) that
  37. * ends when size is 0
  38. */
  39. struct boot_param_header {
  40. u32 magic; /* magic word OF_DT_HEADER */
  41. u32 totalsize; /* total size of DT block */
  42. u32 off_dt_struct; /* offset to structure */
  43. u32 off_dt_strings; /* offset to strings */
  44. u32 off_mem_rsvmap; /* offset to memory reserve map */
  45. u32 version; /* format version */
  46. u32 last_comp_version; /* last compatible version */
  47. /* version 2 fields below */
  48. u32 boot_cpuid_phys; /* Physical CPU id we're booting on */
  49. /* version 3 fields below */
  50. u32 dt_strings_size; /* size of the DT strings block */
  51. /* version 17 fields below */
  52. u32 dt_struct_size; /* size of the DT structure block */
  53. };
  54. /* For scanning the flat device-tree at boot time */
  55. extern int __init of_scan_flat_dt(int (*it)(unsigned long node,
  56. const char *uname, int depth,
  57. void *data),
  58. void *data);
  59. extern void __init *of_get_flat_dt_prop(unsigned long node, const char *name,
  60. unsigned long *size);
  61. extern int __init of_flat_dt_is_compatible(unsigned long node,
  62. const char *name);
  63. extern unsigned long __init of_get_flat_dt_root(void);
  64. #endif /* __ASSEMBLY__ */
  65. #endif /* _LINUX_OF_FDT_H */