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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
*/
#include <assert.h>
#include <ctype.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libfdt.h>
#include "util.h"
/* These are the operations we support */
enum oper_type {
OPER_WRITE_PROP, /* Write a property in a node */
OPER_CREATE_NODE, /* Create a new node */
};
struct display_info {
enum oper_type oper; /* operation to perform */
int type; /* data type (s/i/u/x or 0 for default) */
int size; /* data size (1/2/4) */
int verbose; /* verbose output */
int auto_path; /* automatically create all path components */
};
/**
* Report an error with a particular node.
*
* @param name Node name to report error on
* @param namelen Length of node name, or -1 to use entire string
* @param err Error number to report (-FDT_ERR_...)
*/
static void report_error(const char *name, int namelen, int err)
{
if (namelen == -1)
namelen = strlen(name);
fprintf(stderr, "Error at '%1.*s': %s\n", namelen, name,
fdt_strerror(err));
}
/**
* Encode a series of arguments in a property value.
*
* @param disp Display information / options
* @param arg List of arguments from command line
* @param arg_count Number of arguments (may be 0)
* @param valuep Returns buffer containing value
* @param *value_len Returns length of value encoded
*/
static int encode_value(struct display_info *disp, char **arg, int arg_count,
char **valuep, int *value_len)
{
char *value = NULL; /* holding area for value */
int value_size = 0; /* size of holding area */
char *ptr; /* pointer to current value position */
int len; /* length of this cell/string/byte */
int ival;
int upto; /* the number of bytes we have written to buf */
char fmt[3];
upto = 0;
if (disp->verbose)
fprintf(stderr, "Decoding value:\n");
fmt[0] = '%';
fmt[1] = disp->type ? disp->type : 'd';
fmt[2] = '\0';
for (; arg_count > 0; arg++, arg_count--, upto += len) {
/* assume integer unless told otherwise */
if (disp->type == 's')
len = strlen(*arg) + 1;
else
len = disp->size == -1 ? 4 : disp->size;
/* enlarge our value buffer by a suitable margin if needed */
if (upto + len > value_size) {
value_size = (upto + len) + 500;
value = realloc(value, value_size);
if (!value) {
fprintf(stderr, "Out of mmory: cannot alloc "
"%d bytes\n", value_size);
return -1;
}
}
ptr = value + upto;
if (disp->type == 's') {
memcpy(ptr, *arg, len);
if (disp->verbose)
fprintf(stderr, "\tstring: '%s'\n", ptr);
} else {
int *iptr = (int *)ptr;
sscanf(*arg, fmt, &ival);
if (len == 4)
*iptr = cpu_to_fdt32(ival);
else
*ptr = (uint8_t)ival;
if (disp->verbose) {
fprintf(stderr, "\t%s: %d\n",
disp->size == 1 ? "byte" :
disp->size == 2 ? "short" : "int",
ival);
}
}
}
*value_len = upto;
*valuep = value;
if (disp->verbose)
fprintf(stderr, "Value size %d\n", upto);
return 0;
}
static int store_key_value(void *blob, const char *node_name,
const char *property, const char *buf, int len)
{
int node;
int err;
node = fdt_path_offset(blob, node_name);
if (node < 0) {
report_error(node_name, -1, node);
return -1;
}
err = fdt_setprop(blob, node, property, buf, len);
if (err) {
report_error(property, -1, err);
return -1;
}
return 0;
}
/**
* Create paths as needed for all components of a path
*
* Any components of the path that do not exist are created. Errors are
* reported.
*
* @param blob FDT blob to write into
* @param in_path Path to process
* @return 0 if ok, -1 on error
*/
static int create_paths(void *blob, const char *in_path)
{
const char *path = in_path;
const char *sep;
int node, offset = 0;
/* skip leading '/' */
while (*path == '/')
path++;
for (sep = path; *sep; path = sep + 1, offset = node) {
/* equivalent to strchrnul(), but it requires _GNU_SOURCE */
sep = strchr(path, '/');
if (!sep)
sep = path + strlen(path);
node = fdt_subnode_offset_namelen(blob, offset, path,
sep - path);
if (node == -FDT_ERR_NOTFOUND) {
node = fdt_add_subnode_namelen(blob, offset, path,
sep - path);
}
if (node < 0) {
report_error(path, sep - path, node);
return -1;
}
}
return 0;
}
/**
* Create a new node in the fdt.
*
* This will overwrite the node_name string. Any error is reported.
*
* TODO: Perhaps create fdt_path_offset_namelen() so we don't need to do this.
*
* @param blob FDT blob to write into
* @param node_name Name of node to create
* @return new node offset if found, or -1 on failure
*/
static int create_node(void *blob, const char *node_name)
{
int node = 0;
char *p;
p = strrchr(node_name, '/');
if (!p) {
report_error(node_name, -1, -FDT_ERR_BADPATH);
return -1;
}
*p = '\0';
if (p > node_name) {
node = fdt_path_offset(blob, node_name);
if (node < 0) {
report_error(node_name, -1, node);
return -1;
}
}
node = fdt_add_subnode(blob, node, p + 1);
if (node < 0) {
report_error(p + 1, -1, node);
return -1;
}
return 0;
}
static int do_fdtput(struct display_info *disp, const char *filename,
char **arg, int arg_count)
{
char *value;
char *blob;
int len, ret = 0;
blob = utilfdt_read(filename);
if (!blob)
return -1;
switch (disp->oper) {
case OPER_WRITE_PROP:
/*
* Convert the arguments into a single binary value, then
* store them into the property.
*/
assert(arg_count >= 2);
if (disp->auto_path && create_paths(blob, *arg))
return -1;
if (encode_value(disp, arg + 2, arg_count - 2, &value, &len) ||
store_key_value(blob, *arg, arg[1], value, len))
ret = -1;
break;
case OPER_CREATE_NODE:
for (; ret >= 0 && arg_count--; arg++) {
if (disp->auto_path)
ret = create_paths(blob, *arg);
else
ret = create_node(blob, *arg);
}
break;
}
if (ret >= 0)
ret = utilfdt_write(filename, blob);
free(blob);
return ret;
}
static const char *usage_msg =
"fdtput - write a property value to a device tree\n"
"\n"
"The command line arguments are joined together into a single value.\n"
"\n"
"Usage:\n"
" fdtput <options> <dt file> <node> <property> [<value>...]\n"
" fdtput -c <options> <dt file> [<node>...]\n"
"Options:\n"
"\t-c\t\tCreate nodes if they don't already exist\n"
"\t-p\t\tAutomatically create nodes as needed for the node path\n"
"\t-t <type>\tType of data\n"
"\t-v\t\tVerbose: display each value decoded from command line\n"
"\t-h\t\tPrint this help\n\n"
USAGE_TYPE_MSG;
static void usage(const char *msg)
{
if (msg)
fprintf(stderr, "Error: %s\n\n", msg);
fprintf(stderr, "%s", usage_msg);
exit(2);
}
int main(int argc, char *argv[])
{
struct display_info disp;
char *filename = NULL;
memset(&disp, '\0', sizeof(disp));
disp.size = -1;
disp.oper = OPER_WRITE_PROP;
for (;;) {
int c = getopt(argc, argv, "chpt:v");
if (c == -1)
break;
/*
* TODO: add options to:
* - delete property
* - delete node (optionally recursively)
* - rename node
* - pack fdt before writing
* - set amount of free space when writing
* - expand fdt if value doesn't fit
*/
switch (c) {
case 'c':
disp.oper = OPER_CREATE_NODE;
break;
case 'h':
case '?':
usage(NULL);
case 'p':
disp.auto_path = 1;
break;
case 't':
if (utilfdt_decode_type(optarg, &disp.type,
&disp.size))
usage("Invalid type string");
break;
case 'v':
disp.verbose = 1;
break;
}
}
if (optind < argc)
filename = argv[optind++];
if (!filename)
usage("Missing filename");
argv += optind;
argc -= optind;
if (disp.oper == OPER_WRITE_PROP) {
if (argc < 1)
usage("Missing node");
if (argc < 2)
usage("Missing property");
}
if (do_fdtput(&disp, filename, argv, argc))
return 1;
return 0;
}