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>

internal.c

@@ -165,6 +165,12 @@ uint32_t internal_chip_readl(const chipaddr addr)
 	return mmio_readl((void *) addr);
 }
 
+void internal_chip_readn(uint8_t *buf, const chipaddr addr, size_t len)
+{
+	memcpy(buf, (void *)addr, len);
+	return;
+}
+
 void mmio_writeb(uint8_t val, void *addr)
 {
 	*(volatile uint8_t *) addr = val;
@@ -249,3 +255,19 @@ uint32_t fallback_chip_readl(const chipaddr addr)
 	val |= chip_readw(addr + 2) << 16;
 	return val;
 }
+
+void fallback_chip_writen(uint8_t *buf, chipaddr addr, size_t len)
+{
+	size_t i;
+	for (i = 0; i < len; i++)
+		chip_writeb(buf[i], addr + i);
+	return;
+}
+
+void fallback_chip_readn(uint8_t *buf, chipaddr addr, size_t len)
+{
+	size_t i;
+	for (i = 0; i < len; i++)
+		buf[i] = chip_readb(addr + i);
+	return;
+}