From 9b84076f0a3db7be57325f2251b4cc3b725df8f7 Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@linux.intel.com>
Date: Mon, 1 Oct 2018 13:40:32 +0100
Subject: [PATCH] sam: update to new irq, tty logic

---
 Kernel/platform-sam/sam.s    | 20 +++++++++++++++++++-
 Kernel/platform-sam/sam_vt.s | 31 +++++++------------------------
 Kernel/platform-sam/tricks.s |  1 +
 3 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/Kernel/platform-sam/sam.s b/Kernel/platform-sam/sam.s
index 68304b55..de2cdd3f 100644
--- a/Kernel/platform-sam/sam.s
+++ b/Kernel/platform-sam/sam.s
@@ -22,6 +22,7 @@
 	    .globl _platform_copier_l
 	    .globl _platform_copier_h
 	    .globl _keyscan
+	    .globl _int_disabled
 
             ; exported debugging tools
             .globl _platform_monitor
@@ -66,6 +67,9 @@ _platform_reboot:
 	    out (250), a		; ROM appears low
 	    rst 0			; bang
 
+_int_disabled:
+	    .db 1
+
 ; -----------------------------------------------------------------------------
 ;	We have discard mapped high up so we can map stuff under it
 ;	during setup. All of discard gets reclaimed when init is run
@@ -176,14 +180,28 @@ map_page_low:
 	    or #0x20			; force ROM off
 	    out (250),a
 	    ret
+;
+;	The video map requires interrupt disables. Do the disable in
+;	map_video. Save the old state in af' and then restore int in
+;	unmap_video
+;
+;
 map_video:
+	    ld a,(_int_disabled)
+	    ex af,af'
+	    di
 	    in a,(250)
 	    ld (video_save),a
 	    ld a,#VIDEO_LOW
 	    jr map_page_low
 unmap_video:
 	    ld a,(video_save)
-	    jr map_page_low
+	    call map_page_low
+	    ex af,af'
+	    or a
+	    ret nz
+	    ei
+	    ret
 
 _program_vectors:
             ; we are called, with interrupts disabled, by both newproc() and crt0
diff --git a/Kernel/platform-sam/sam_vt.s b/Kernel/platform-sam/sam_vt.s
index 6eb46f32..045f327d 100644
--- a/Kernel/platform-sam/sam_vt.s
+++ b/Kernel/platform-sam/sam_vt.s
@@ -32,7 +32,6 @@
 
 	.globl map_video
 	.globl unmap_video
-	.globl ___hard_di
 
 _fontdata_8x8_exp2	.equ	0x6000	; in video bank
 
@@ -63,30 +62,21 @@ base_addr:
 ;	hell out of everything else. For now just di. 32K/32K splits suck
 ;
 _scroll_up:
-	call ___hard_di
-	push af
 	call map_video
 	ld hl,#1024
 	ld de,#0
 	ld bc,#24576-1024
-ldir_pop:
 	ldir
 pop_unmap:
-	call unmap_video
-	pop af
-	ret c
-	ei
-	ret
+	jp unmap_video
 
 _scroll_down:
-	call ___hard_di
-	push af
 	call map_video
 	ld hl,#24575-1024
 	ld de,#24575
 	ld bc,#24576
 	lddr
-	jr pop_unmap
+	jp unmap_video
 
 _plot_char:
 	pop hl			; return
@@ -95,8 +85,6 @@ _plot_char:
 	push bc
 	push de
 	push hl
-	call ___hard_di
-	push af
 	call base_addr
 	ld h,#0
 	ld l,c
@@ -168,15 +156,13 @@ plot_loop_slow:
 	ex af,af'
 	dec a
 	jr nz, plot_loop_slow
-	jr pop_unmap
+	jp unmap_video
 
 _clear_lines:
 	pop hl
 	pop de
 	push de
 	push hl
-	call ___hard_di
-	push af
 	ld a,d			; count (0-23)
 	ld d,#0
 	; Now how much to copy ?
@@ -192,7 +178,8 @@ _clear_lines:
 	inc de
 	dec bc
 	ld (hl),#0
-	jp ldir_pop
+	ldir
+	jp unmap_video
 
 _clear_across:
 	pop hl
@@ -202,9 +189,6 @@ _clear_across:
 	push de
 	push hl
 
-	call ___hard_di
-	push af
-
 	call base_addr
 	call map_video
 
@@ -224,7 +208,7 @@ wipe_rowpair:
 	inc d	; to worry about carries just restore low, inc high
 	dec l
 	jr nz, wipe_line
-	jp pop_unmap
+	jp unmap_video
 
 _vtwipe:
 	call map_video
@@ -233,8 +217,7 @@ _vtwipe:
 	ld bc,#24575
 	ld (hl),#0
 	ldir
-	call unmap_video
-	ret
+	jp unmap_video
 ;
 ;	TODO
 ;
diff --git a/Kernel/platform-sam/tricks.s b/Kernel/platform-sam/tricks.s
index 127d4f31..b507876b 100644
--- a/Kernel/platform-sam/tricks.s
+++ b/Kernel/platform-sam/tricks.s
@@ -111,6 +111,7 @@ skip_copyback:
 
 	; if we pre-empted in an ISR IRQ's stay off, if not they get enabled
 	ld a, (U_DATA__U_ININTERRUPT)
+	ld (_int_disabled), a
 	or a
 	ret nz
 	ei
-- 
2.34.1