Sometimes we want to read/write more than 4 bytes of chip content at once

Add chip_{read,write}n to the external flasher infrastructure which
read/write n bytes at once.

Fix a few places where the code used memcpy/memcmp although that is
strictly impossible with external flashers.
Place a FIXME in the layout.c code because usage is not totally clear
and needs to be fixed to support external flashers.

As a nice side benefit, we get a noticeable speedup for builtin flash
reading which is now a memcpy() of the full flash area instead of a
series of single-byte reads.

Corresponding to flashrom svn r579.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Urja Rannikko <urjaman@gmail.com>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
diff --git a/dummyflasher.c b/dummyflasher.c
index 784cc55..64b083e 100644
--- a/dummyflasher.c
+++ b/dummyflasher.c
@@ -103,6 +103,18 @@
 	printf_debug("%s: addr=0x%lx, val=0x%08x\n", __func__, addr, val);
 }
 
+void dummy_chip_writen(uint8_t *buf, chipaddr addr, size_t len)
+{
+	size_t i;
+	printf_debug("%s: addr=0x%lx, len=0x%08lx, writing data (hex):",
+		     __func__, addr, (unsigned long)len);
+	for (i = 0; i < len; i++) {
+		if ((i % 16) == 0)
+			printf_debug("\n");
+		printf_debug("%02x ", buf[i])
+	}
+}
+
 uint8_t dummy_chip_readb(const chipaddr addr)
 {
 	printf_debug("%s:  addr=0x%lx, returning 0xff\n", __func__, addr);
@@ -121,6 +133,14 @@
 	return 0xffffffff;
 }
 
+void dummy_chip_readn(uint8_t *buf, const chipaddr addr, size_t len)
+{
+	printf_debug("%s:  addr=0x%lx, len=0x%lx, returning array of 0xff\n",
+		     __func__, addr, (unsigned long)len);
+	memset(buf, 0xff, len);
+	return;
+}
+
 int dummy_spi_command(unsigned int writecnt, unsigned int readcnt,
 		      const unsigned char *writearr, unsigned char *readarr)
 {