auto import from //depot/cupcake/@135843
diff --git a/toolbox/hd.c b/toolbox/hd.c
new file mode 100644
index 0000000..1f7d179
--- /dev/null
+++ b/toolbox/hd.c
@@ -0,0 +1,95 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+
+int hd_main(int argc, char *argv[])
+{
+ int c;
+ int fd;
+ unsigned char buf[4096];
+ int res;
+ int read_len;
+ int rv = 0;
+ int i;
+ int filepos = 0;
+ int sum;
+ int lsum;
+
+ int base = -1;
+ int count = 0;
+ int repeat = 0;
+
+ do {
+ c = getopt(argc, argv, "b:c:r:");
+ if (c == EOF)
+ break;
+ switch (c) {
+ case 'b':
+ base = strtol(optarg, NULL, 0);
+ break;
+ case 'c':
+ count = strtol(optarg, NULL, 0);
+ break;
+ case 'r':
+ repeat = strtol(optarg, NULL, 0);
+ break;
+ case '?':
+ fprintf(stderr, "%s: invalid option -%c\n",
+ argv[0], optopt);
+ exit(1);
+ }
+ } while (1);
+
+ if (optind + 1 != argc) {
+ fprintf(stderr, "Usage: %s [-b base] [-c count] [-r delay] file\n", argv[0]);
+ exit(1);
+ }
+
+ fd = open(argv[optind], O_RDONLY);
+ if(fd < 0) {
+ fprintf(stderr, "could not open %s, %s\n", argv[optind], strerror(errno));
+ return 1;
+ }
+
+ do {
+ if(base >= 0) {
+ lseek(fd, base, SEEK_SET);
+ filepos = base;
+ }
+ sum = 0;
+ lsum = 0;
+ while(1) {
+ read_len = sizeof(buf);
+ if(count > 0 && base + count - filepos < read_len)
+ read_len = base + count - filepos;
+ res = read(fd, &buf, read_len);
+ for(i = 0; i < res; i++) {
+ if((i & 15) == 0) {
+ printf("%08x: ", filepos + i);
+ }
+ lsum += buf[i];
+ sum += buf[i];
+ printf("%02x ", buf[i]);
+ if(((i & 15) == 15) || (i == res - 1)) {
+ printf("s %x\n", lsum);
+ lsum = 0;
+ }
+ }
+ if(res <= 0) {
+ printf("Read error on %s, offset %d len %d, %s\n", argv[optind], filepos, read_len, strerror(errno));
+ return 1;
+ }
+ filepos += res;
+ if(filepos == base + count)
+ break;
+ }
+ printf("sum %x\n", sum);
+ if(repeat)
+ sleep(repeat);
+ } while(repeat);
+ return 0;
+}