This simply utility makes it easy for scripts to read values from the device tree.
Signed-off-by: Simon Glass <[email protected]> --- .gitignore | 1 + Makefile | 7 ++ Makefile.dtget | 13 ++++ dtget.c | 207 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 228 insertions(+), 0 deletions(-) create mode 100644 Makefile.dtget create mode 100644 dtget.c diff --git a/.gitignore b/.gitignore index ae7a46a..cde4fa5 100644 --- a/.gitignore +++ b/.gitignore @@ -10,3 +10,4 @@ lex.yy.c /ftdump /convert-dtsv0 /version_gen.h +/dtget diff --git a/Makefile b/Makefile index 22f79a0..3401a65 100644 --- a/Makefile +++ b/Makefile @@ -106,10 +106,12 @@ endef include Makefile.convert-dtsv0 include Makefile.dtc include Makefile.ftdump +include Makefile.dtget BIN += convert-dtsv0 BIN += dtc BIN += ftdump +BIN += dtget SCRIPTS = dtdiff @@ -120,6 +122,7 @@ ifneq ($(DEPTARGETS),) -include $(DTC_OBJS:%.o=%.d) -include $(CONVERT_OBJS:%.o=%.d) -include $(FTDUMP_OBJS:%.o=%.d) +-include $(DTGET_OBJS:%.o=%.d) endif @@ -180,6 +183,10 @@ convert-dtsv0: $(CONVERT_OBJS) ftdump: $(FTDUMP_OBJS) +dtget: $(DTGET_OBJS) $(LIBFDT_archive) + $(VECHO) LD $@ + $(LINK.c) -o $@ $^ + # # Testsuite rules diff --git a/Makefile.dtget b/Makefile.dtget new file mode 100644 index 0000000..edda499 --- /dev/null +++ b/Makefile.dtget @@ -0,0 +1,13 @@ +# +# This is not a complete Makefile. +# Instead, it is designed to be easily embeddable +# into other systems of Makefiles. +# + +DTGET_SRCS = \ + dtget.c \ + util.c + +DTGET_GEN_SRCS = + +DTGET_OBJS = $(DTGET_SRCS:%.c=%.o) $(DTGET_GEN_SRCS:%.c=%.o) diff --git a/dtget.c b/dtget.c new file mode 100644 index 0000000..0ee577c --- /dev/null +++ b/dtget.c @@ -0,0 +1,207 @@ +/* + * Copyright (c) 2011 The Chromium OS Authors. All rights reserved. + * Distributed under the terms of the GNU General Public License v2 + * + * is_printable_string from ftdump.c + * Contributed by Pantelis Antoniou <pantelis.antoniou AT gmail.com> + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <getopt.h> +#include <ctype.h> + +#include <libfdt.h> + +#include "util.h" + +#define FTDUMP_BUF_SIZE 65536 + +static void report_error(const char *where, int err) +{ + fprintf(stderr, "Error at '%s': %s\n", where, fdt_strerror(err)); +} + +static void show_data(const char *format, int type, const char *data, int len) +{ + int i, size; + const char *p = data, *s; + int value; + int is_string; + + /* no data, don't print */ + if (len == 0) + return; + + is_string = type == 's' || + (!type && util_is_printable_string(data, len)); + if (is_string) { + for (s = data; s - data < len; s += strlen(s) + 1) { + if (s != data) + printf(" "); + printf(format ? format : "%s", (const char *)s); + } + return; + } + if (type == 'i') + size = 4; + else if (type == 'b') + size = 1; + else + size = len % 4 == 0 ? 4 : 1; + for (i = 0; i < len; i += size, p += size) { + if (i) + printf(" "); + value = size == 4 ? fdt32_to_cpu(*(const uint32_t *)p) : + *(const unsigned char *)p; + printf(format ? format : "%d", value); + } +} + +static int show_data_for_key(const void *blob, const char *format, int type, + char *key) +{ + char *ptr, *prop; + int node, guess_node = 0; + const void *value; + int len; + + /* First extract the property from the end */ + ptr = strrchr(key, '/'); + if (!ptr) { + fprintf(stderr, "No node found in key '%s'\n", key); + return 5; + } + + if (ptr == key) { + guess_node = fdt_path_offset(blob, key); + node = fdt_path_offset(blob, "/"); + } else { + *ptr = '\0'; + node = fdt_path_offset(blob, key); + *ptr = '/'; + } + if (node < 0) { + report_error(key, node); + return 7; + } + prop = ptr + 1; + value = fdt_getprop(blob, node, prop, &len); + if (!value) { + report_error(prop, len); + if (guess_node) + fprintf(stderr, "(Node %s exists but you didn't " + "specify a property to print)\n", key); + return 8; + } + show_data(format, type, value, len); + printf("\n"); + return 0; +} + +static int do_dtget(const char *filename, const char *format, int type, + char **key, int key_count) +{ + FILE *fp; + char *buf; + size_t size; + int i, ret; + + if (strcmp(filename, "-") == 0) { + fp = stdin; + } else { + fp = fopen(filename, "rb"); + if (fp == NULL) { + fprintf(stderr, "unable to open %s\n", filename); + return 10; + } + } + + buf = malloc(FTDUMP_BUF_SIZE); + if (!buf) { + fprintf(stderr, "Couldn't allocate %d byte buffer\n", + FTDUMP_BUF_SIZE); + return 10; + } + + size = fread(buf, 1, FTDUMP_BUF_SIZE, fp); + if (!feof(fp)) { + fprintf(stderr, "file too large (maximum is %d bytes)\n", + FTDUMP_BUF_SIZE); + return 10; + } + if (ferror(fp)) { + fprintf(stderr, "file read error\n"); + return 10; + } + for (i = 0; i < key_count; i++) { + ret = show_data_for_key(buf, format, type, key[i]); + if (ret) + return ret; + } + return 0; +} + +static void usage(const char *msg) +{ + if (msg) + fprintf(stderr, "Error: %s\n\n", msg); + fprintf(stderr, "dtget - read values from device tree\n\n"); + fprintf(stderr, "Usage: dtget <options> <dt file> <key>...\n"); + fprintf(stderr, "Options:\n"); + fprintf(stderr, "\t-f, --format <fmt>\tPrintf format string to use " + "for value\n"); + fprintf(stderr, "\t-t, --type <typechar>\tForce type to be string " + "(s), int(i) or byte(b)\n"); + fprintf(stderr, "\t-h, --help\t\tPrint this help\n\n"); + fprintf(stderr, "\t<key> is <node>/<property>, for example " + "/lcd/width for the width\n"); + fprintf(stderr, "\tproperty in the LCD node\n"); + exit(2); +} + +int main(int argc, char *argv[]) +{ + int c; + int ret; + char *format = NULL; + int type = 0; + char *filename = NULL; + static struct option long_options[] = { + {"format", 1, 0, 'f'}, + {"help", 1, 0, 'h'}, + {"type", 1, 0, 't'}, + {0, 0, 0, 0} + }; + + for (;;) { + c = getopt_long(argc, argv, "f:ht:", long_options, NULL); + if (c == -1) + break; + + switch (c) { + case 'h': + case '?': + usage(""); + + case 'f': + format = optarg; + break; + + case 't': + type = *optarg; + break; + } + } + + if (optind < argc) + filename = argv[optind++]; + if (!filename) + usage("Missing filename"); + if (optind == argc) + usage("Missing key(s)"); + + ret = do_dtget(filename, format, type, argv + optind, argc - optind); + return ret; +} -- 1.7.3.1 _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
