add alternate command for ipe337 board

board/ipe337/Makefile

@@ -1,3 +1,4 @@
 obj-y += ipe337.o
+obj-y += cmd_alternate.o
 
 extra-y += u-boot.lds

board/ipe337/cmd_alternate.c

@@ -0,0 +1,51 @@
+#include <common.h>
+#include <command.h>
+#include <linux/stat.h>
+#include <malloc.h>
+#include <fs.h>
+
+static int do_alternate (cmd_tbl_t *cmdtp, int argc, char *argv[])
+{
+	void *buf;
+	size_t size;
+	ulong *ptr, val = 0, bitcount = 0;
+
+	if (argc != 2) {
+		u_boot_cmd_usage(cmdtp);
+		return 1;
+	}
+
+	buf = read_file(argv[1], &size);
+	if (!buf)
+		return 1;
+
+	ptr = buf;
+
+	while ((ulong)ptr <= (ulong)buf + size && !(val = *ptr++))
+		bitcount += 32;
+
+	if (val) {
+		do {
+			if (val & 1)
+				break;
+			bitcount++;
+		} while (val >>= 1);
+	}
+
+	printf("bitcount : %d\n", bitcount);
+
+	free(buf);
+	return bitcount & 1 ? 2 : 3;
+}
+
+static __maybe_unused char cmd_alternate_help[] =
+"Usage: alternate <file>\n"
+"\n";
+
+U_BOOT_CMD_START(alternate)
+	.maxargs	= CONFIG_MAXARGS,
+	.cmd		= do_alternate,
+	.usage		= "count zero bits in a file",
+	U_BOOT_CMD_HELP(cmd_alternate_help)
+U_BOOT_CMD_END
+