projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| e169cfbe GL |
1 | /* |
| 2 | * Functions 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 | ||
| 12 | #include <linux/of.h> | |
| 13 | #include <linux/of_fdt.h> | |
| 14 | ||
| 15 | struct boot_param_header *initial_boot_params; | |
| 16 | ||
| 17 | char *find_flat_dt_string(u32 offset) | |
| 18 | { | |
| 19 | return ((char *)initial_boot_params) + | |
| 20 | initial_boot_params->off_dt_strings + offset; | |
| 21 | } | |
| c8cb7a59 GL |
22 | |
| 23 | /** | |
| 24 | * of_scan_flat_dt - scan flattened tree blob and call callback on each. | |
| 25 | * @it: callback function | |
| 26 | * @data: context data pointer | |
| 27 | * | |
| 28 | * This function is used to scan the flattened device-tree, it is | |
| 29 | * used to extract the memory information at boot before we can | |
| 30 | * unflatten the tree | |
| 31 | */ | |
| 32 | int __init of_scan_flat_dt(int (*it)(unsigned long node, | |
| 33 | const char *uname, int depth, | |
| 34 | void *data), | |
| 35 | void *data) | |
| 36 | { | |
| 37 | unsigned long p = ((unsigned long)initial_boot_params) + | |
| 38 | initial_boot_params->off_dt_struct; | |
| 39 | int rc = 0; | |
| 40 | int depth = -1; | |
| 41 | ||
| 42 | do { | |
| 43 | u32 tag = *((u32 *)p); | |
| 44 | char *pathp; | |
| 45 | ||
| 46 | p += 4; | |
| 47 | if (tag == OF_DT_END_NODE) { | |
| 48 | depth--; | |
| 49 | continue; | |
| 50 | } | |
| 51 | if (tag == OF_DT_NOP) | |
| 52 | continue; | |
| 53 | if (tag == OF_DT_END) | |
| 54 | break; | |
| 55 | if (tag == OF_DT_PROP) { | |
| 56 | u32 sz = *((u32 *)p); | |
| 57 | p += 8; | |
| 58 | if (initial_boot_params->version < 0x10) | |
| 59 | p = _ALIGN(p, sz >= 8 ? 8 : 4); | |
| 60 | p += sz; | |
| 61 | p = _ALIGN(p, 4); | |
| 62 | continue; | |
| 63 | } | |
| 64 | if (tag != OF_DT_BEGIN_NODE) { | |
| 65 | pr_err("Invalid tag %x in flat device tree!\n", tag); | |
| 66 | return -EINVAL; | |
| 67 | } | |
| 68 | depth++; | |
| 69 | pathp = (char *)p; | |
| 70 | p = _ALIGN(p + strlen(pathp) + 1, 4); | |
| 71 | if ((*pathp) == '/') { | |
| 72 | char *lp, *np; | |
| 73 | for (lp = NULL, np = pathp; *np; np++) | |
| 74 | if ((*np) == '/') | |
| 75 | lp = np+1; | |
| 76 | if (lp != NULL) | |
| 77 | pathp = lp; | |
| 78 | } | |
| 79 | rc = it(p, pathp, depth, data); | |
| 80 | if (rc != 0) | |
| 81 | break; | |
| 82 | } while (1); | |
| 83 | ||
| 84 | return rc; | |
| 85 | } |