// 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;}