dtbhtool: Split out dtimg components

Factor out DT image creation code into a small host
library.

Create a new host binary which allows us to create
device tree blob (DTB) images.

Change-Id: I5424684ad467b952df8b2ccf3afbacdec03e88c9
diff --git a/dtbhtool/mkdtbimg.c b/dtbhtool/mkdtbimg.c
new file mode 100644
index 0000000..d5fda12
--- /dev/null
+++ b/dtbhtool/mkdtbimg.c
@@ -0,0 +1,126 @@
+/* tools/mkbootimg/mkdtbimg.c
+**
+** Copyright 2016-2017, The LineageOS Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+**
+** December 2016, Christopher N. Hesse
+** Separate dt creation from mkbootimg program.
+**
+** January 2017, Christopher N. Hesse
+** Adjust to dtbToolCM call syntax.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <limits.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <arpa/inet.h>
+#include <assert.h>
+#include <dirent.h>
+#include <err.h>
+#include <stdint.h>
+
+#include <dtbimg.h>
+
+int usage(void)
+{
+    fprintf(stderr,"usage: mkdtimg\n"
+            "       --dt_dir <dtb path>\n"
+            "       -o|--output <filename>\n"
+            );
+    return 1;
+}
+
+
+
+int main(int argc, char **argv)
+{
+    char *dtimg = 0;
+    char *dt_dir = 0;
+    void *dt_data = 0;
+    unsigned pagesize = 0;
+    unsigned default_pagesize = 2048;
+    uint32_t dt_size;
+    int fd;
+    struct stat sbuf;
+
+    argc--;
+    argv++;
+
+    while(argc > 0){
+        char *arg = argv[0];
+        char *val = argv[1];
+        if(argc < 1) {
+            return usage();
+        }
+        argc -= 2;
+        argv += 2;
+        if(!strcmp(arg, "--output") || !strcmp(arg, "-o")) {
+            dtimg = val;
+        } else if (!strcmp(arg, "--dt_dir")) {
+            dt_dir = val;
+        } else if (!strcmp(arg, "-p")) {
+            // Ignore this parameter
+        } else if (!strcmp(arg, "-s")) {
+            pagesize = strtol(val, NULL, 10);
+            if (pagesize == 0)
+                pagesize = default_pagesize;
+        } else {
+            // Check if this is the dtb path
+            int err = stat(arg, &sbuf);
+            if (err != 0 || !S_ISDIR(sbuf.st_mode))
+                return usage();
+            dt_dir = arg;
+        }
+    }
+
+    if(dtimg == 0) {
+        fprintf(stderr,"error: no output filename specified\n");
+        return usage();
+    }
+
+    if(dt_dir == 0) {
+        fprintf(stderr,"error: no dtb path specified\n");
+        return usage();
+    }
+
+    dt_data = load_dtbh_block(dt_dir, pagesize, &dt_size);
+    if (dt_data == 0) {
+        fprintf(stderr, "error: could not load device tree blobs '%s'\n", dt_dir);
+        return 1;
+    }
+
+    fd = open(dtimg, O_CREAT | O_TRUNC | O_WRONLY, 0644);
+    if(fd < 0) {
+        fprintf(stderr,"error: could not create '%s'\n", dtimg);
+        return 1;
+    }
+
+    if(write(fd, dt_data, dt_size) != dt_size) goto fail;
+
+    return 0;
+
+fail:
+    unlink(dtimg);
+    close(fd);
+    fprintf(stderr,"error: failed writing '%s': %s\n", dtimg,
+            strerror(errno));
+    return 1;
+}