From ba7c96396fcc0ea9f2dec3ec0fdb91b95505e942 Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@etchedpixels.co.uk>
Date: Fri, 28 Nov 2014 22:05:47 +0000
Subject: [PATCH] dragon: SAM implementation of the user memory copier

---
 Kernel/platform-dragon/usermem_sam.s | 116 +++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 Kernel/platform-dragon/usermem_sam.s

diff --git a/Kernel/platform-dragon/usermem_sam.s b/Kernel/platform-dragon/usermem_sam.s
new file mode 100644
index 00000000..b21ecf5b
--- /dev/null
+++ b/Kernel/platform-dragon/usermem_sam.s
@@ -0,0 +1,116 @@
+	.module usermem
+
+;
+;	6809 + SAM copy to and from userspace
+;
+;	This is linked by the 6881 using platforms only. MMU based
+;	machines simply don't need it.
+
+
+	include "kernel.def"
+        include "../kernel09.def"
+
+	.globl __ugetc
+	.globl __ugetw
+	.globl __uget
+	.globl __ugets
+
+	.globl __uputc
+	.globl __uputw
+	.globl __uput
+	.globl __uzero
+
+	.area .common
+
+__ugetc:
+	SAM_USER
+	ldb ,x
+	lda #0
+	tfr d,x
+	SAM_KERNEL
+	rts
+
+__ugetw:
+	SAM_USER
+	ldx ,x
+	SAM_KERNEL
+	rts
+
+__uget:
+	pshs u,y
+	ldu 6,s		; user address
+	ldy 8,s		; count
+ugetl:
+	lda ,x++
+	SAM_USER
+	sta ,u++
+	SAM_KERNEL
+	leay -1,y
+	cmpy #0
+	bne ugetl
+	puls u,y,pc
+
+__ugets:
+	pshs u,y
+	ldu 6,s		; user address
+	ldy 8,s		; count
+ugetsl:
+	SAM_USER
+	lda ,x++
+	beq ugetse
+	SAM_KERNEL
+	sta ,u++
+	leay -1,y
+	cmpy #0
+	bne ugetsl
+	ldx #0xffff	; unterminated - error
+	lda #0
+	sta -1,u	; force termination
+	puls u,y,pc
+
+ugetse:
+	SAM_KERNEL
+	sta ,u
+	ldx #0
+	puls u,y,pc
+
+
+__uputc:
+	SAM_USER
+	stb ,x
+	SAM_KERNEL
+	rts
+
+__uputw:
+	SAM_USER
+	ldb 2,s
+	stb ,x
+	SAM_KERNEL
+	rts
+
+__uput:
+	pshs u,y
+	ldu 6,s		; user address
+	ldy 8,s		; count
+uputl:
+	SAM_USER
+	lda ,x++
+	SAM_KERNEL
+	sta ,u++
+	leay -1,y
+	cmpy #0
+	bne uputl
+	puls u,y,pc
+
+__uzero:
+	pshs y
+	lda #0
+	ldy 6,s
+	SAM_USER
+uzloop:
+	sta ,x+
+	leay -1,y
+	cmpy #0
+	bne uzloop
+	SAM_KERNEL
+	puls y,pc
-- 
2.34.1