[PATCH 3_9] Move buffer print code from md command to common function

Printing a buffer is a darn useful thing.  Move the buffer print code
into print_buffer() in lib_generic/

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/lib_generic/display_options.c b/lib_generic/display_options.c
index 512e898..5ddd94f 100644
--- a/lib_generic/display_options.c
+++ b/lib_generic/display_options.c
@@ -21,7 +21,10 @@
  * MA 02111-1307 USA
  */
 
+#include <config.h>
 #include <common.h>
+#include <linux/ctype.h>
+#include <asm/io.h>
 
 int display_options (void)
 {
@@ -65,3 +68,70 @@
 	}
 	printf (" %cB%s", c, s);
 }
+
+/*
+ * Print data buffer in hex and ascii form to the terminal.
+ *
+ * data reads are buffered so that each memory address is only read once.
+ * Useful when displaying the contents of volatile registers.
+ *
+ * parameters:
+ *    addr: Starting address to display at start of line
+ *    data: pointer to data buffer
+ *    width: data value width.  May be 1, 2, or 4.
+ *    count: number of values to display
+ *    linelen: Number of values to print per line; specify 0 for default length
+ */
+#define MAX_LINE_LENGTH_BYTES (64)
+#define DEFAULT_LINE_LENGTH_BYTES (16)
+int print_buffer (ulong addr, void* data, uint width, uint count, uint linelen)
+{
+	uint8_t linebuf[MAX_LINE_LENGTH_BYTES];
+	uint32_t *uip = (void*)linebuf;
+	uint16_t *usp = (void*)linebuf;
+	uint8_t *ucp = (void*)linebuf;
+	int i;
+
+	if (linelen*width > MAX_LINE_LENGTH_BYTES)
+		linelen = MAX_LINE_LENGTH_BYTES / width;
+	if (linelen < 1)
+		linelen = DEFAULT_LINE_LENGTH_BYTES / width;
+
+	while (count) {
+		printf("%08lx:", addr);
+
+		/* check for overflow condition */
+		if (count < linelen)
+			linelen = count;
+
+		/* Copy from memory into linebuf and print hex values */
+		for (i = 0; i < linelen; i++) {
+			if (width == 4) {
+				uip[i] = *(volatile uint32_t *)data;
+				printf(" %08x", uip[i]);
+			} else if (width == 2) {
+				usp[i] = *(volatile uint16_t *)data;
+				printf(" %04x", usp[i]);
+			} else {
+				ucp[i] = *(volatile uint8_t *)data;
+				printf(" %02x", ucp[i]);
+			}
+			data += width;
+		}
+
+		/* Print data in ASCII characters */
+		puts("    ");
+		for (i = 0; i < linelen * width; i++)
+			putc(isprint(ucp[i]) && (ucp[i] < 0x80) ? ucp[i] : '.');
+		putc ('\n');
+
+		/* update references */
+		addr += linelen * width;
+		count -= linelen;
+
+		if (ctrlc())
+			return -1;
+	}
+
+	return 0;
+}