memdump: a debugging utility to dump memory over a serial port

A memory-dumping utility which runs in real mode.  Thus, it can be
used to get memory dumps from a relatively pristine system.

1 files changed, 23 insertions, 0 deletions

diff --git a/memdump/memcpy.S b/memdump/memcpy.S
new file mode 100644
index 00000000..76eef73c
--- /dev/null
+++ b/memdump/memcpy.S
@@ -0,0 +1,23 @@
+#
+# memcpy.S
+#
+# Simple 16-bit memcpy() implementation
+#
+
+	.text
+	.code16gcc
+	.globl memcpy
+	.type memcpy, @function
+memcpy:
+	cld
+	pushw %di
+	pushw %si
+	movw %ax,%di
+	movw %dx,%si
+	# The third argument is already in cx
+	rep ; movsb
+	popw %si
+	popw %di
+	ret
+
+	.size memcpy,.-memcpy