From 7072b70c3dc2aaf94128da1592b09eaf51854926 Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@linux.intel.com>
Date: Fri, 30 Jan 2015 17:51:55 +0000
Subject: [PATCH] z80: make the outfoo routines preserve everything

They are mostly used for debug, so having them eat AF is just too good a way to
have them muck up the debug work.
---
 Kernel/lowlevel-z80.s           | 17 ++++++++++++-----
 Kernel/platform-socz80/socz80.s |  3 ++-
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/Kernel/lowlevel-z80.s b/Kernel/lowlevel-z80.s
index 85bf1a77..c923d5eb 100644
--- a/Kernel/lowlevel-z80.s
+++ b/Kernel/lowlevel-z80.s
@@ -483,30 +483,37 @@ outnewline:
         call outchar
         ret
 
-outhl:  ; prints HL in hex. Destroys AF.
+outhl:  ; prints HL in hex.
+	push af
         ld a, h
         call outcharhex
         ld a, l
         call outcharhex
+	pop af
         ret
 
-outbc:  ; prints BC in hex. Destroys AF.
+outbc:  ; prints BC in hex.
+	push af
         ld a, b
         call outcharhex
         ld a, c
         call outcharhex
+	pop af
         ret
 
-outde:  ; prints DE in hex. Destroys AF.
+outde:  ; prints DE in hex.
+	push af
         ld a, d
         call outcharhex
         ld a, e
         call outcharhex
+	pop af
         ret
 
 ; print the byte in A as a two-character hex value
 outcharhex:
         push bc
+	push af
         ld c, a  ; copy value
         ; print the top nibble
         rra
@@ -517,6 +524,7 @@ outcharhex:
         ; print the bottom nibble
         ld a, c
         call outnibble
+	pop af
         pop bc
         ret
 
@@ -527,8 +535,7 @@ outnibble:
         jr c, numeral ; less than 10?
         add a, #0x07 ; start at 'A' (10+7+0x30=0x41='A')
 numeral:add a, #0x30 ; start at '0' (0x30='0')
-        call outchar
-        ret
+        jp outchar
 
 ;
 ;	Pull in the CPU specific workarounds
diff --git a/Kernel/platform-socz80/socz80.s b/Kernel/platform-socz80/socz80.s
index 825b0d90..16bbd158 100644
--- a/Kernel/platform-socz80/socz80.s
+++ b/Kernel/platform-socz80/socz80.s
@@ -559,9 +559,9 @@ saved_map:  .db 0, 0, 0, 0
 map_current: .db 0, 0, 0, 0
 
 ; outchar: Wait for UART TX idle, then print the char in A
-; destroys: AF
 outchar:
             push bc
+	    push af
             ld b, a
             ; wait for transmitter to be idle
 ocloop:     in a, (UART0_STATUS)
@@ -570,5 +570,6 @@ ocloop:     in a, (UART0_STATUS)
             ; now output the char to serial port
             ld a, b
             out (UART0_DATA), a
+	    pop af
             pop bc
             ret
-- 
2.34.1