scripts/dtc/fdtget.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
  *
  * Portions from U-Boot cmd_fdt.c (C) Copyright 2007
  * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com
  * Based on code written by:
  *   Pantelis Antoniou <pantelis.antoniou@gmail.com> and
  *   Matthew McClintock <msm@freescale.com>
  */

 #include <assert.h>
 #include <ctype.h>
 #include <getopt.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 #include <libfdt.h>

 #include "util.h"

 enum display_mode {
 	MODE_SHOW_VALUE,	/* show values for node properties */
 	MODE_LIST_PROPS,	/* list the properties for a node */
 	MODE_LIST_SUBNODES,	/* list the subnodes of a node */
 };

 /* Holds information which controls our output and options */
 struct display_info {
 	int type;		/* data type (s/i/u/x or 0 for default) */
 	int size;		/* data size (1/2/4) */
 	enum display_mode mode;	/* display mode that we are using */
 	const char *default_val; /* default value if node/property not found */
 };

 static void report_error(const char *where, int err)
 {
 	fprintf(stderr, "Error at '%s': %s\n", where, fdt_strerror(err));
 }

 /**
  * Displays data of a given length according to selected options
  *
  * If a specific data type is provided in disp, then this is used. Otherwise
  * we try to guess the data type / size from the contents.
  *
  * @param disp		Display information / options
  * @param data		Data to display
  * @param len		Maximum length of buffer
  * @return 0 if ok, -1 if data does not match format
  */
 static int show_data(struct display_info *disp, const char *data, int len)
 {
 	int i, size;
 	const uint8_t *p = (const uint8_t *)data;
 	const char *s;
 	int value;
 	int is_string;
 	char fmt[3];

 	/* no data, don't print */
 	if (len == 0)
 		return 0;

 	is_string = (disp->type) == 's' ||
 		(!disp->type && util_is_printable_string(data, len));
 	if (is_string) {
 		if (data[len - 1] != '\0') {
 			fprintf(stderr, "Unterminated string\n");
 			return -1;
 		}
 		for (s = data; s - data < len; s += strlen(s) + 1) {
 			if (s != data)
 				printf(" ");
 			printf("%s", (const char *)s);
 		}
 		return 0;
 	}
 	size = disp->size;
 	if (size == -1) {
 		size = (len % 4) == 0 ? 4 : 1;
 	} else if (len % size) {
 		fprintf(stderr, "Property length must be a multiple of "
 				"selected data size\n");
 		return -1;
 	}
 	fmt[0] = '%';
 	fmt[1] = disp->type ? disp->type : 'd';
 	fmt[2] = '\0';
 	for (i = 0; i < len; i += size, p += size) {
 		if (i)
 			printf(" ");
 		value = size == 4 ? fdt32_to_cpu(*(const uint32_t *)p) :
 			size == 2 ? (*p << 8) | p[1] : *p;
 		printf(fmt, value);
 	}
 	return 0;
 }

 /**
  * List all properties in a node, one per line.
  *
  * @param blob		FDT blob
  * @param node		Node to display
  * @return 0 if ok, or FDT_ERR... if not.
  */
 static int list_properties(const void *blob, int node)
 {
 	const struct fdt_property *data;
 	const char *name;
 	int prop;

 	prop = fdt_first_property_offset(blob, node);
 	do {
 		/* Stop silently when there are no more properties */
 		if (prop < 0)
 			return prop == -FDT_ERR_NOTFOUND ? 0 : prop;
 		data = fdt_get_property_by_offset(blob, prop, NULL);
 		name = fdt_string(blob, fdt32_to_cpu(data->nameoff));
 		if (name)
 			puts(name);
 		prop = fdt_next_property_offset(blob, prop);
 	} while (1);
 }

 #define MAX_LEVEL	32		/* how deeply nested we will go */

 /**
  * List all subnodes in a node, one per line
  *
  * @param blob		FDT blob
  * @param node		Node to display
  * @return 0 if ok, or FDT_ERR... if not.
  */
 static int list_subnodes(const void *blob, int node)
 {
 	int nextoffset;		/* next node offset from libfdt */
 	uint32_t tag;		/* current tag */
 	int level = 0;		/* keep track of nesting level */
 	const char *pathp;
 	int depth = 1;		/* the assumed depth of this node */

 	while (level >= 0) {
 		tag = fdt_next_tag(blob, node, &nextoffset);
 		switch (tag) {
 		case FDT_BEGIN_NODE:
 			pathp = fdt_get_name(blob, node, NULL);
 			if (level <= depth) {
 				if (pathp == NULL)
 					pathp = "/* NULL pointer error */";
 				if (*pathp == '\0')
 					pathp = "/";	/* root is nameless */
 				if (level == 1)
 					puts(pathp);
 			}
 			level++;
 			if (level >= MAX_LEVEL) {
 				printf("Nested too deep, aborting.\n");
 				return 1;
 			}
 			break;
 		case FDT_END_NODE:
 			level--;
 			if (level == 0)
 				level = -1;		/* exit the loop */
 			break;
 		case FDT_END:
 			return 1;
 		case FDT_PROP:
 			break;
 		default:
 			if (level <= depth)
 				printf("Unknown tag 0x%08X\n", tag);
 			return 1;
 		}
 		node = nextoffset;
 	}
 	return 0;
 }

 /**
  * Show the data for a given node (and perhaps property) according to the
  * display option provided.
  *
  * @param blob		FDT blob
  * @param disp		Display information / options
  * @param node		Node to display
  * @param property	Name of property to display, or NULL if none
  * @return 0 if ok, -ve on error
  */
 static int show_data_for_item(const void *blob, struct display_info *disp,
 		int node, const char *property)
 {
 	const void *value = NULL;
 	int len, err = 0;

 	switch (disp->mode) {
 	case MODE_LIST_PROPS:
 		err = list_properties(blob, node);
 		break;

 	case MODE_LIST_SUBNODES:
 		err = list_subnodes(blob, node);
 		break;

 	default:
 		assert(property);
 		value = fdt_getprop(blob, node, property, &len);
 		if (value) {
 			if (show_data(disp, value, len))
 				err = -1;
 			else
 				printf("\n");
 		} else if (disp->default_val) {
 			puts(disp->default_val);
 		} else {
 			report_error(property, len);
 			err = -1;
 		}
 		break;
 	}

 	return err;
 }

 /**
  * Run the main fdtget operation, given a filename and valid arguments
  *
  * @param disp		Display information / options
  * @param filename	Filename of blob file
  * @param arg		List of arguments to process
  * @param arg_count	Number of arguments
  * @param return 0 if ok, -ve on error
  */
 static int do_fdtget(struct display_info *disp, const char *filename,
 		     char **arg, int arg_count, int args_per_step)
 {
 	char *blob;
 	const char *prop;
 	int i, node;

 	blob = utilfdt_read(filename);
 	if (!blob)
 		return -1;

 	for (i = 0; i + args_per_step <= arg_count; i += args_per_step) {
 		node = fdt_path_offset(blob, arg[i]);
 		if (node < 0) {
 			if (disp->default_val) {
 				puts(disp->default_val);
 				continue;
 			} else {
 				report_error(arg[i], node);
 				return -1;
 			}
 		}
 		prop = args_per_step == 1 ? NULL : arg[i + 1];

 		if (show_data_for_item(blob, disp, node, prop))
 			return -1;
 	}
 	return 0;
 }

 static const char *usage_msg =
 	"fdtget - read values from device tree\n"
 	"\n"
 	"Each value is printed on a new line.\n\n"
 	"Usage:\n"
 	"	fdtget <options> <dt file> [<node> <property>]...\n"
 	"	fdtget -p <options> <dt file> [<node> ]...\n"
 	"Options:\n"
 	"\t-t <type>\tType of data\n"
 	"\t-p\t\tList properties for each node\n"
 	"\t-l\t\tList subnodes for each node\n"
 	"\t-d\t\tDefault value to display when the property is "
 			"missing\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[])
 {
 	char *filename = NULL;
 	struct display_info disp;
 	int args_per_step = 2;

 	/* set defaults */
 	memset(&disp, '\0', sizeof(disp));
 	disp.size = -1;
 	disp.mode = MODE_SHOW_VALUE;
 	for (;;) {
 		int c = getopt(argc, argv, "d:hlpt:");
 		if (c == -1)
 			break;

 		switch (c) {
 		case 'h':
 		case '?':
 			usage(NULL);

 		case 't':
 			if (utilfdt_decode_type(optarg, &disp.type,
 					&disp.size))
 				usage("Invalid type string");
 			break;

 		case 'p':
 			disp.mode = MODE_LIST_PROPS;
 			args_per_step = 1;
 			break;

 		case 'l':
 			disp.mode = MODE_LIST_SUBNODES;
 			args_per_step = 1;
 			break;

 		case 'd':
 			disp.default_val = optarg;
 			break;
 		}
 	}

 	if (optind < argc)
 		filename = argv[optind++];
 	if (!filename)
 		usage("Missing filename");

 	argv += optind;
 	argc -= optind;

 	/* Allow no arguments, and silently succeed */
 	if (!argc)
 		return 0;

 	/* Check for node, property arguments */
 	if (args_per_step == 2 && (argc % 2))
 		usage("Must have an even number of arguments");

 	if (do_fdtget(&disp, filename, argv, argc, args_per_step))
 		return 1;
 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
	*
	* Portions from U-Boot cmd_fdt.c (C) Copyright 2007
	* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com
	* Based on code written by:
	* Pantelis Antoniou <pantelis.antoniou@gmail.com> and
	* Matthew McClintock <msm@freescale.com>
	*/

	#include <assert.h>
	#include <ctype.h>
	#include <getopt.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>

	#include <libfdt.h>

	#include "util.h"

	enum display_mode {
	MODE_SHOW_VALUE, /* show values for node properties */
	MODE_LIST_PROPS, /* list the properties for a node */
	MODE_LIST_SUBNODES, /* list the subnodes of a node */
	};

	/* Holds information which controls our output and options */
	struct display_info {
	int type; /* data type (s/i/u/x or 0 for default) */
	int size; /* data size (1/2/4) */
	enum display_mode mode; /* display mode that we are using */
	const char default_val; / default value if node/property not found */
	};

	static void report_error(const char *where, int err)
	{
	fprintf(stderr, "Error at '%s': %s\n", where, fdt_strerror(err));
	}

	/**
	* Displays data of a given length according to selected options
	*
	* If a specific data type is provided in disp, then this is used. Otherwise
	* we try to guess the data type / size from the contents.
	*
	* @param disp Display information / options
	* @param data Data to display
	* @param len Maximum length of buffer
	* @return 0 if ok, -1 if data does not match format
	*/
	static int show_data(struct display_info disp, const char data, int len)
	{
	int i, size;
	const uint8_t p = (const uint8_t )data;
	const char *s;
	int value;
	int is_string;
	char fmt[3];

	/* no data, don't print */
	if (len == 0)
	return 0;

	is_string = (disp->type) == 's' \|\|
	(!disp->type && util_is_printable_string(data, len));
	if (is_string) {
	if (data[len - 1] != '\0') {
	fprintf(stderr, "Unterminated string\n");
	return -1;
	}
	for (s = data; s - data < len; s += strlen(s) + 1) {
	if (s != data)
	printf(" ");
	printf("%s", (const char *)s);
	}
	return 0;
	}
	size = disp->size;
	if (size == -1) {
	size = (len % 4) == 0 ? 4 : 1;
	} else if (len % size) {
	fprintf(stderr, "Property length must be a multiple of "
	"selected data size\n");
	return -1;
	}
	fmt[0] = '%';
	fmt[1] = disp->type ? disp->type : 'd';
	fmt[2] = '\0';
	for (i = 0; i < len; i += size, p += size) {
	if (i)
	printf(" ");
	value = size == 4 ? fdt32_to_cpu((const uint32_t )p) :
	size == 2 ? (p << 8) \| p[1] : p;
	printf(fmt, value);
	}
	return 0;
	}

	/**
	* List all properties in a node, one per line.
	*
	* @param blob FDT blob
	* @param node Node to display
	* @return 0 if ok, or FDT_ERR... if not.
	*/
	static int list_properties(const void *blob, int node)
	{
	const struct fdt_property *data;
	const char *name;
	int prop;

	prop = fdt_first_property_offset(blob, node);
	do {
	/* Stop silently when there are no more properties */
	if (prop < 0)
	return prop == -FDT_ERR_NOTFOUND ? 0 : prop;
	data = fdt_get_property_by_offset(blob, prop, NULL);
	name = fdt_string(blob, fdt32_to_cpu(data->nameoff));
	if (name)
	puts(name);
	prop = fdt_next_property_offset(blob, prop);
	} while (1);
	}

	#define MAX_LEVEL 32 /* how deeply nested we will go */

	/**
	* List all subnodes in a node, one per line
	*
	* @param blob FDT blob
	* @param node Node to display
	* @return 0 if ok, or FDT_ERR... if not.
	*/
	static int list_subnodes(const void *blob, int node)
	{
	int nextoffset; /* next node offset from libfdt */
	uint32_t tag; /* current tag */
	int level = 0; /* keep track of nesting level */
	const char *pathp;
	int depth = 1; /* the assumed depth of this node */

	while (level >= 0) {
	tag = fdt_next_tag(blob, node, &nextoffset);
	switch (tag) {
	case FDT_BEGIN_NODE:
	pathp = fdt_get_name(blob, node, NULL);
	if (level <= depth) {
	if (pathp == NULL)
	pathp = "/* NULL pointer error */";
	if (*pathp == '\0')
	pathp = "/"; /* root is nameless */
	if (level == 1)
	puts(pathp);
	}
	level++;
	if (level >= MAX_LEVEL) {
	printf("Nested too deep, aborting.\n");
	return 1;
	}
	break;
	case FDT_END_NODE:
	level--;
	if (level == 0)
	level = -1; /* exit the loop */
	break;
	case FDT_END:
	return 1;
	case FDT_PROP:
	break;
	default:
	if (level <= depth)
	printf("Unknown tag 0x%08X\n", tag);
	return 1;
	}
	node = nextoffset;
	}
	return 0;
	}

	/**
	* Show the data for a given node (and perhaps property) according to the
	* display option provided.
	*
	* @param blob FDT blob
	* @param disp Display information / options
	* @param node Node to display
	* @param property Name of property to display, or NULL if none
	* @return 0 if ok, -ve on error
	*/
	static int show_data_for_item(const void blob, struct display_info disp,
	int node, const char *property)
	{
	const void *value = NULL;
	int len, err = 0;

	switch (disp->mode) {
	case MODE_LIST_PROPS:
	err = list_properties(blob, node);
	break;

	case MODE_LIST_SUBNODES:
	err = list_subnodes(blob, node);
	break;

	default:
	assert(property);
	value = fdt_getprop(blob, node, property, &len);
	if (value) {
	if (show_data(disp, value, len))
	err = -1;
	else
	printf("\n");
	} else if (disp->default_val) {
	puts(disp->default_val);
	} else {
	report_error(property, len);
	err = -1;
	}
	break;
	}

	return err;
	}

	/**
	* Run the main fdtget operation, given a filename and valid arguments
	*
	* @param disp Display information / options
	* @param filename Filename of blob file
	* @param arg List of arguments to process
	* @param arg_count Number of arguments
	* @param return 0 if ok, -ve on error
	*/
	static int do_fdtget(struct display_info disp, const char filename,
	char **arg, int arg_count, int args_per_step)
	{
	char *blob;
	const char *prop;
	int i, node;

	blob = utilfdt_read(filename);
	if (!blob)
	return -1;

	for (i = 0; i + args_per_step <= arg_count; i += args_per_step) {
	node = fdt_path_offset(blob, arg[i]);
	if (node < 0) {
	if (disp->default_val) {
	puts(disp->default_val);
	continue;
	} else {
	report_error(arg[i], node);
	return -1;
	}
	}
	prop = args_per_step == 1 ? NULL : arg[i + 1];

	if (show_data_for_item(blob, disp, node, prop))
	return -1;
	}
	return 0;
	}

	static const char *usage_msg =
	"fdtget - read values from device tree\n"
	"\n"
	"Each value is printed on a new line.\n\n"
	"Usage:\n"
	" fdtget <options> <dt file> [<node> <property>]...\n"
	" fdtget -p <options> <dt file> [<node> ]...\n"
	"Options:\n"
	"\t-t <type>\tType of data\n"
	"\t-p\t\tList properties for each node\n"
	"\t-l\t\tList subnodes for each node\n"
	"\t-d\t\tDefault value to display when the property is "
	"missing\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[])
	{
	char *filename = NULL;
	struct display_info disp;
	int args_per_step = 2;

	/* set defaults */
	memset(&disp, '\0', sizeof(disp));
	disp.size = -1;
	disp.mode = MODE_SHOW_VALUE;
	for (;;) {
	int c = getopt(argc, argv, "d:hlpt:");
	if (c == -1)
	break;

	switch (c) {
	case 'h':
	case '?':
	usage(NULL);

	case 't':
	if (utilfdt_decode_type(optarg, &disp.type,
	&disp.size))
	usage("Invalid type string");
	break;

	case 'p':
	disp.mode = MODE_LIST_PROPS;
	args_per_step = 1;
	break;

	case 'l':
	disp.mode = MODE_LIST_SUBNODES;
	args_per_step = 1;
	break;

	case 'd':
	disp.default_val = optarg;
	break;
	}
	}

	if (optind < argc)
	filename = argv[optind++];
	if (!filename)
	usage("Missing filename");

	argv += optind;
	argc -= optind;

	/* Allow no arguments, and silently succeed */
	if (!argc)
	return 0;

	/* Check for node, property arguments */
	if (args_per_step == 2 && (argc % 2))
	usage("Must have an even number of arguments");

	if (do_fdtget(&disp, filename, argv, argc, args_per_step))
	return 1;
	return 0;
	}