Add fdt read/write utility functions
This adds higher-level libfdt operations for reading/writing an fdt
blob from/to a file, as well as a function to decode a data type string
as will be used by fdtget, fdtput.
This also adds a few tests for the simple type argument supported by
utilfdt_decode_type.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/util.c b/util.c
index 6d07292..d82d41f 100644
--- a/util.c
+++ b/util.c
@@ -1,4 +1,5 @@
/*
+ * Copyright 2011 The Chromium Authors, All Rights Reserved.
* Copyright 2008 Jon Loeliger, Freescale Semiconductor, Inc.
*
* util_is_printable_string contributed by
@@ -27,6 +28,11 @@
#include <string.h>
#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "libfdt.h"
#include "util.h"
char *xstrdup(const char *s)
@@ -184,3 +190,139 @@
(*i) = j;
return val;
}
+
+int utilfdt_read_err(const char *filename, char **buffp)
+{
+ int fd = 0; /* assume stdin */
+ char *buf = NULL;
+ off_t bufsize = 1024, offset = 0;
+ int ret = 0;
+
+ *buffp = NULL;
+ if (strcmp(filename, "-") != 0) {
+ fd = open(filename, O_RDONLY);
+ if (fd < 0)
+ return errno;
+ }
+
+ /* Loop until we have read everything */
+ buf = malloc(bufsize);
+ do {
+ /* Expand the buffer to hold the next chunk */
+ if (offset == bufsize) {
+ bufsize *= 2;
+ buf = realloc(buf, bufsize);
+ if (!buf) {
+ ret = ENOMEM;
+ break;
+ }
+ }
+
+ ret = read(fd, &buf[offset], bufsize - offset);
+ if (ret < 0) {
+ ret = errno;
+ break;
+ }
+ offset += ret;
+ } while (ret != 0);
+
+ /* Clean up, including closing stdin; return errno on error */
+ close(fd);
+ if (ret)
+ free(buf);
+ else
+ *buffp = buf;
+ return ret;
+}
+
+char *utilfdt_read(const char *filename)
+{
+ char *buff;
+ int ret = utilfdt_read_err(filename, &buff);
+
+ if (ret) {
+ fprintf(stderr, "Couldn't open blob from '%s': %s\n", filename,
+ strerror(ret));
+ return NULL;
+ }
+ /* Successful read */
+ return buff;
+}
+
+int utilfdt_write_err(const char *filename, const void *blob)
+{
+ int fd = 1; /* assume stdout */
+ int totalsize;
+ int offset;
+ int ret = 0;
+ const char *ptr = blob;
+
+ if (strcmp(filename, "-") != 0) {
+ fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+ if (fd < 0)
+ return errno;
+ }
+
+ totalsize = fdt_totalsize(blob);
+ offset = 0;
+
+ while (offset < totalsize) {
+ ret = write(fd, ptr + offset, totalsize - offset);
+ if (ret < 0) {
+ ret = -errno;
+ break;
+ }
+ offset += ret;
+ }
+ /* Close the file/stdin; return errno on error */
+ if (fd != 1)
+ close(fd);
+ return ret < 0 ? -ret : 0;
+}
+
+
+int utilfdt_write(const char *filename, const void *blob)
+{
+ int ret = utilfdt_write_err(filename, blob);
+
+ if (ret) {
+ fprintf(stderr, "Couldn't write blob to '%s': %s\n", filename,
+ strerror(ret));
+ }
+ return ret ? -1 : 0;
+}
+
+int utilfdt_decode_type(const char *fmt, int *type, int *size)
+{
+ int qualifier = 0;
+
+ /* get the conversion qualifier */
+ *size = -1;
+ if (strchr("hlLb", *fmt)) {
+ qualifier = *fmt++;
+ if (qualifier == *fmt) {
+ switch (*fmt++) {
+/* TODO: case 'l': qualifier = 'L'; break;*/
+ case 'h':
+ qualifier = 'b';
+ break;
+ }
+ }
+ }
+
+ /* we should now have a type */
+ if (!strchr("iuxs", *fmt))
+ return -1;
+
+ /* convert qualifier (bhL) to byte size */
+ if (*fmt != 's')
+ *size = qualifier == 'b' ? 1 :
+ qualifier == 'h' ? 2 :
+ qualifier == 'l' ? 4 : -1;
+ *type = *fmt++;
+
+ /* that should be it! */
+ if (*fmt)
+ return -1;
+ return 0;
+}