blob: 3f7804eab988de99a1e133db2f719c9750fcbd08 [file] [log] [blame]
/*
* Copyright 2018 Google LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "hf/fdt.h"
#include <stdint.h>
#include "hf/dlog.h"
#include "hf/std.h"
struct fdt_header {
uint32_t magic;
uint32_t totalsize;
uint32_t off_dt_struct;
uint32_t off_dt_strings;
uint32_t off_mem_rsvmap;
uint32_t version;
uint32_t last_comp_version;
uint32_t boot_cpuid_phys;
uint32_t size_dt_strings;
uint32_t size_dt_struct;
};
struct fdt_reserve_entry {
uint64_t address;
uint64_t size;
};
enum fdt_token {
FDT_BEGIN_NODE = 1,
FDT_END_NODE = 2,
FDT_PROP = 3,
FDT_NOP = 4,
FDT_END = 9,
};
struct fdt_tokenizer {
const char *cur;
const char *end;
const char *strs;
};
#define FDT_VERSION 17
#define FDT_MAGIC 0xd00dfeed
static void fdt_tokenizer_init(struct fdt_tokenizer *t, const char *strs,
const char *begin, const char *end)
{
t->strs = strs;
t->cur = begin;
t->end = end;
}
static void fdt_tokenizer_align(struct fdt_tokenizer *t)
{
t->cur = (char *)(((uintptr_t)t->cur + 3) & ~3);
}
static bool fdt_tokenizer_uint32(struct fdt_tokenizer *t, uint32_t *res)
{
const char *next = t->cur + sizeof(*res);
if (next > t->end) {
return false;
}
*res = be32toh(*(uint32_t *)t->cur);
t->cur = next;
return true;
}
static bool fdt_tokenizer_token(struct fdt_tokenizer *t, uint32_t *res)
{
uint32_t v;
while (fdt_tokenizer_uint32(t, &v)) {
if (v != FDT_NOP) {
*res = v;
return true;
}
}
return false;
}
static bool fdt_tokenizer_bytes(struct fdt_tokenizer *t, const char **res,
size_t size)
{
const char *next = t->cur + size;
if (next > t->end) {
return false;
}
*res = t->cur;
t->cur = next;
fdt_tokenizer_align(t);
return true;
}
static bool fdt_tokenizer_str(struct fdt_tokenizer *t, const char **res)
{
const char *p;
for (p = t->cur; p < t->end; p++) {
if (!*p) {
/* Found the end of the string. */
*res = t->cur;
t->cur = p + 1;
fdt_tokenizer_align(t);
return true;
}
}
return false;
}
bool fdt_root_node(struct fdt_node *node, const struct fdt_header *hdr)
{
uint32_t max_ver;
uint32_t min_ver;
uint32_t begin = be32toh(hdr->off_dt_struct);
uint32_t size = be32toh(hdr->size_dt_struct);
memset(node, 0, sizeof(*node));
/* Check the magic number before anything else. */
if (hdr->magic != be32toh(FDT_MAGIC)) {
return false;
}
/* Check the version. */
max_ver = be32toh(hdr->version);
min_ver = be32toh(hdr->last_comp_version);
if (FDT_VERSION < min_ver || FDT_VERSION > max_ver) {
return false;
}
/* TODO: Verify that it is all within the fdt. */
node->begin = (const char *)hdr + begin;
node->end = node->begin + size;
/* TODO: Verify strings as well. */
node->strs = (char *)hdr + be32toh(hdr->off_dt_strings);
return true;
}
static bool fdt_next_property(struct fdt_tokenizer *t, const char **name,
const char **buf, uint32_t *size)
{
uint32_t token;
uint32_t nameoff;
if (!fdt_tokenizer_token(t, &token)) {
return false;
}
if (token != FDT_PROP) {
/* Rewind so that caller will get the same token. */
t->cur -= sizeof(uint32_t);
return false;
}
if (!fdt_tokenizer_uint32(t, size) ||
!fdt_tokenizer_uint32(t, &nameoff) ||
!fdt_tokenizer_bytes(t, buf, *size)) {
/*
* Move cursor to the end so that caller won't get any new
* tokens.
*/
t->cur = t->end;
return false;
}
/* TODO: Need to verify the strings. */
*name = t->strs + nameoff;
return true;
}
static bool fdt_next_subnode(struct fdt_tokenizer *t, const char **name)
{
uint32_t token;
if (!fdt_tokenizer_token(t, &token)) {
return false;
}
if (token != FDT_BEGIN_NODE) {
/* Rewind so that caller will get the same token. */
t->cur -= sizeof(uint32_t);
return false;
}
if (!fdt_tokenizer_str(t, name)) {
/*
* Move cursor to the end so that caller won't get any new
* tokens.
*/
t->cur = t->end;
return false;
}
return true;
}
static void fdt_skip_properties(struct fdt_tokenizer *t)
{
const char *name;
const char *buf;
uint32_t size;
while (fdt_next_property(t, &name, &buf, &size)) {
/* do nothing */
}
}
static bool fdt_skip_node(struct fdt_tokenizer *t)
{
const char *name;
uint32_t token;
size_t pending = 1;
fdt_skip_properties(t);
do {
while (fdt_next_subnode(t, &name)) {
fdt_skip_properties(t);
pending++;
}
if (!fdt_tokenizer_token(t, &token)) {
return false;
}
if (token != FDT_END_NODE) {
t->cur = t->end;
return false;
}
pending--;
} while (pending);
return true;
}
bool fdt_read_property(const struct fdt_node *node, const char *name,
const char **buf, uint32_t *size)
{
struct fdt_tokenizer t;
const char *prop_name;
fdt_tokenizer_init(&t, node->strs, node->begin, node->end);
while (fdt_next_property(&t, &prop_name, buf, size)) {
if (!strcmp(prop_name, name)) {
return true;
}
}
return false;
}
bool fdt_first_child(struct fdt_node *node, const char **child_name)
{
struct fdt_tokenizer t;
fdt_tokenizer_init(&t, node->strs, node->begin, node->end);
fdt_skip_properties(&t);
if (!fdt_next_subnode(&t, child_name)) {
return false;
}
node->begin = t.cur;
return true;
}
bool fdt_next_sibling(struct fdt_node *node, const char **sibling_name)
{
struct fdt_tokenizer t;
fdt_tokenizer_init(&t, node->strs, node->begin, node->end);
if (!fdt_skip_node(&t)) {
return false;
}
if (!fdt_next_subnode(&t, sibling_name)) {
return false;
}
node->begin = t.cur;
return true;
}
bool fdt_find_child(struct fdt_node *node, const char *child)
{
struct fdt_tokenizer t;
const char *name;
fdt_tokenizer_init(&t, node->strs, node->begin, node->end);
fdt_skip_properties(&t);
while (fdt_next_subnode(&t, &name)) {
if (!strcmp(name, child)) {
node->begin = t.cur;
return true;
}
fdt_skip_node(&t);
}
return false;
}
void fdt_dump(struct fdt_header *hdr)
{
uint32_t token;
size_t depth = 0;
const char *name;
struct fdt_tokenizer t;
struct fdt_node node;
/* Traverse the whole thing. */
if (!fdt_root_node(&node, hdr)) {
dlog("FDT failed validation.\n");
return;
}
fdt_tokenizer_init(&t, node.strs, node.begin, node.end);
do {
while (fdt_next_subnode(&t, &name)) {
const char *buf;
uint32_t size;
dlog("%*sNew node: \"%s\"\n", 2 * depth, "", name);
depth++;
while (fdt_next_property(&t, &name, &buf, &size)) {
size_t i;
dlog("%*sproperty: \"%s\" (", 2 * depth, "",
name);
for (i = 0; i < size; i++) {
dlog("%s%02x", i == 0 ? "" : " ",
buf[i]);
}
dlog(")\n");
}
}
if (!fdt_tokenizer_token(&t, &token)) {
return;
}
if (token != FDT_END_NODE) {
return;
}
depth--;
} while (depth);
dlog("fdt: off_mem_rsvmap=%u\n", be32toh(hdr->off_mem_rsvmap));
{
struct fdt_reserve_entry *e =
(struct fdt_reserve_entry
*)((size_t)hdr + be32toh(hdr->off_mem_rsvmap));
while (e->address || e->size) {
dlog("Entry: %p (0x%x bytes)\n", be64toh(e->address),
be64toh(e->size));
e++;
}
}
}
void fdt_add_mem_reservation(struct fdt_header *hdr, size_t addr, size_t len)
{
/* TODO: Clean this up. */
char *begin = (char *)hdr + be32toh(hdr->off_mem_rsvmap);
struct fdt_reserve_entry *e = (struct fdt_reserve_entry *)begin;
hdr->totalsize = htobe32(be32toh(hdr->totalsize) +
sizeof(struct fdt_reserve_entry));
hdr->off_dt_struct = htobe32(be32toh(hdr->off_dt_struct) +
sizeof(struct fdt_reserve_entry));
hdr->off_dt_strings = htobe32(be32toh(hdr->off_dt_strings) +
sizeof(struct fdt_reserve_entry));
memmove(begin + sizeof(struct fdt_reserve_entry), begin,
be32toh(hdr->totalsize) - be32toh(hdr->off_mem_rsvmap));
e->address = htobe64(addr);
e->size = htobe64(len);
}
size_t fdt_header_size(void)
{
return sizeof(struct fdt_header);
}
size_t fdt_total_size(struct fdt_header *hdr)
{
return be32toh(hdr->totalsize);
}