Switch the display file and graphics routines to using the getc stack

The file display and graphics routines used their own file management
since the old getc code did not nest.  The new one does (necessary to
support INCLUDE), so use the same routines and get rid of the ad hoc
buffer management.

9 files changed, 90 insertions, 185 deletions

diff --git a/conio.inc b/conio.inc
index 7d1424da..47005961 100644
--- a/conio.inc
+++ b/conio.inc
@@ -43,54 +43,31 @@ loadkeys_ret:	ret
 
 ;
 ; get_msg_file: Load a text file and write its contents to the screen,
-;               interpreting color codes.  Is called with SI and DX:AX
-;               set by routine searchdir
+;               interpreting color codes.  Call with the file already
+;		on the top of the open/getc stack.
+;
+;		Assumes CS == DS == ES.
 ;
 get_msg_file:
-		push es
-		shl edx,16			; EDX <- DX:AX (length of file)
-		mov dx,ax
-		mov ax,xfer_buf_seg		; Use for temporary storage
-		mov es,ax
-
                 mov byte [TextAttribute],07h	; Default grey on white
 		mov byte [DisplayMask],07h	; Display text in all modes
 		call msg_initvars
 
-get_msg_chunk:  push edx			; EDX = length of file
-		xor bx,bx			; == xbs_textbuf
-		mov cx,[BufSafe]
-		call getfssec
-		pop edx
-		push si				; Save current cluster
-		xor si,si			; == xbs_textbuf
-		mov cx,[BufSafeBytes]		; Number of bytes left in chunk
 print_msg_file:
-		push cx
-		push edx
-		es lodsb
+.getc:
+		call getc
+		jc .done
                 cmp al,1Ah                      ; DOS EOF?
-		je msg_done_pop
-		push si
-		mov cl,[UsingVGA]
+		je .done
+		movzx cx,byte [UsingVGA]
 		and cl,01h
 		inc cx				; CL <- 01h = text mode,
 						;       02h = graphics mode
                 call [NextCharJump]		; Do what shall be done
-		pop si
-		pop edx
-                pop cx
-		dec edx
-		jz msg_done
-		loop print_msg_file
-		pop si
-		jmp short get_msg_chunk
-msg_done_pop:
-                add sp,byte 6			; Drop pushed EDX, CX
-msg_done:
-		pop si
-		pop es
-		ret
+		jmp .getc
+.done:
+		jmp close			; Tailcall!
+
 msg_putchar:                                    ; Normal character
                 cmp al,0Fh                      ; ^O = color code follows
                 je msg_ctrl_o
@@ -221,16 +198,12 @@ msg_novga:
 		jmp short msg_initvars
 
 msg_viewimage:
-		push es
-		push ds
-		pop es				; ES <- DS
 		mov si,[VGAFilePtr]
 		mov byte [si],0			; Zero-terminate filename
 		mov si,VGAFileBuf
 		mov di,VGAFileMBuf
 		call mangle_name
-		call searchdir
-		pop es
+		call open
 		jz msg_putcharnext		; Not there
 		call vgadisplayfile
 		; Fall through
diff --git a/extlinux.asm b/extlinux.asm
index 551d02bb..1929b169 100644
--- a/extlinux.asm
+++ b/extlinux.asm
@@ -126,18 +126,6 @@ ClustByteShift	resb 1			; Shift count for bytes/cluster
 		alignb open_file_t_size
 Files		resb MAX_OPEN*open_file_t_size
 
-;
-; Constants for the xfer_buf_seg
-;
-; The xfer_buf_seg is also used to store message file buffers.  We
-; need two trackbuffers (text and graphics), plus a work buffer
-; for the graphics decompressor.
-;
-xbs_textbuf	equ 0			; Also hard-coded, do not change
-xbs_vgabuf	equ trackbufsize
-xbs_vgatmpbuf	equ 2*trackbufsize
-
-
 		section .text
 ;
 ; Some of the things that have to be saved very early are saved
diff --git a/graphics.inc b/graphics.inc
index 28685418..2b8290fc 100644
--- a/graphics.inc
+++ b/graphics.inc
@@ -17,17 +17,13 @@
 ;
 ; vgadisplayfile:
 ;	Display a graphical splash screen.
+;	The file is already opened on the top of the getc stack.
 ;
-; Input:
-;
-; SI	= cluster/socket pointer
+;	Assumes CS == DS == ES.
 ;
 		section .text
 
 vgadisplayfile:
-		mov [VGACluster],si
-		push es
-
 		; This is a cheap and easy way to make sure the screen is
 		; cleared in case we were in graphics mode already
 		call vgaclearmode
@@ -35,26 +31,27 @@ vgadisplayfile:
 		jnz .error_nz
 
 .graphalready:
-		mov ax,xfer_buf_seg		; Use as temporary storage
-		mov es,ax
-		mov fs,ax
-
-		call vgagetchunk		; Get the first chunk
+		; Load the header.
+		mov cx,4+2*2+16*3
+		mov di,LSSHeader
+.gethdr:
+		call getc
+		stosb
+		loop .gethdr
+		jc .error
 
 		; The header WILL be in the first chunk.
-		cmp dword [es:xbs_vgabuf],0x1413f33d	; Magic number
+		cmp dword [LSSMagic],0x1413f33d	; Magic number
 .error_nz:	jne .error
-		mov ax,[es:xbs_vgabuf+4]
-		mov [GraphXSize],ax
 
-		mov dx,xbs_vgabuf+8		; Color map offset
+		mov dx,GraphColorMap		; Color map offset
 		mov ax,1012h			; Set RGB registers
 		xor bx,bx			; First register number
 		mov cx,16			; 16 registers
 		int 10h
 
 .movecursor:
-		mov ax,[es:xbs_vgabuf+6]	; Number of pixel rows
+		mov ax,[GraphYSize]		; Number of pixel rows
 		mov dx,[VGAFontSize]
 		add ax,dx
 		dec ax
@@ -70,50 +67,46 @@ vgadisplayfile:
 		xor bx,bx
 		int 10h				; Set cursor below image
 
-		mov cx,[es:xbs_vgabuf+6]	; Number of graphics rows
-
-		mov si,xbs_vgabuf+8+3*16	; Beginning of pixel data
+		mov cx,[GraphYSize]		; Number of graphics rows
 		mov word [VGAPos],0
 
 .drawpixelrow:
 		push cx
-		mov cx,[GraphXSize]
-		mov di,xbs_vgatmpbuf		; Row buffer
-		call rledecode			; Decode one row
-		push si
-		mov si,xbs_vgatmpbuf
-		mov di,si
-		add di,[GraphXSize]
+		mov di,VGARowBuffer
+		; Pre-clear the row buffer
+		push di
 		mov cx,640/4
 		xor eax,eax
-		rep stosd			; Clear rest of row
+		rep stosd
+		pop di
+		push di
+		mov cx,[GraphXSize]
+		call rledecode			; Decode one row
+		pop si
+		push es
 		mov di,0A000h			; VGA segment
 		mov es,di
 		mov di,[VGAPos]
 		mov bp,640
 		call packedpixel2vga
-		add word [VGAPos],byte 80	; Advance to next pixel row
-		push fs
+		add word [VGAPos],80
 		pop es
-		pop si
 		pop cx
 		loop .drawpixelrow
 
 .error:
-		pop es
-		ret
+		jmp close			; Tailcall!
 
 ;
 ; rledecode:
 ;	Decode a pixel row in RLE16 format.
 ;
-; FS:SI	-> input
-; CX -> pixel count
-; ES:DI -> output (packed pixel)
+; getc stack	-> input
+; CX		-> pixel count
+; ES:DI		-> output (packed pixel)
 ;
 rledecode:
-		shl esi,1		; Nybble pointer
-		xor dl,dl		; Last pixel
+		xor dx,dx		; DL = last pixel, DH = nybble buffer
 .loop:
 		call .getnybble
 		cmp al,dl
@@ -123,15 +116,12 @@ rledecode:
 		dec cx
 		jnz .loop
 .done:
-		shr esi,1
-		adc si,byte 0
 		ret
 .run:
 		xor bx,bx
 		call .getnybble
-		and al,al
+		or bl,al
 		jz .longrun
-		mov bl,al
 .dorun:
 		push cx
 		mov cx,bx
@@ -143,60 +133,32 @@ rledecode:
 		jmp short .done
 .longrun:
 		call .getnybble
-		mov ah,al
+		mov bl,al
 		call .getnybble
 		shl al,4
-		or al,ah
-		mov bl,al
+		or bl,al
 		add bx,16
 		jmp short .dorun
+
 .getnybble:
-		shr esi,1
-		fs lodsb
-		jc .high
-		dec si
-		and al,0Fh
-		stc
-		rcl esi,1
+		test dh,10h
+		jz .low
+		and dh,0Fh
+		mov al,dh
 		ret
-.high:
-		shr al,4
-		cmp si,xbs_vgabuf+trackbufsize	; Chunk overrun
-		jb .nonewchunk
-		call vgagetchunk
-		mov si,xbs_vgabuf		; Start at beginning of buffer
-.nonewchunk:
-		shl esi,1
-		ret
-
-;
-; vgagetchunk:
-;	Get a new trackbufsize chunk of VGA image data
-;
-; On input, ES is assumed to point to the buffer segment.
-;
-vgagetchunk:
-		pushad
-		mov si,[VGACluster]
-		and si,si
-		jz .eof				; EOF overrun, not much to do...
-
-		mov cx,[BufSafe]		; One trackbuf worth of data
-		mov bx,xbs_vgabuf
-		call getfssec
-
-		jnc .noteof
-		xor si,si
-.noteof:	mov [VGACluster],si
-
-.eof:		popad
+.low:
+		call getc
+		mov dh,al
+		shr dh,4
+		or dh,10h		; Nybble already read
+		and al,0Fh
 		ret
 
 ;
 ; packedpixel2vga:
 ;	Convert packed-pixel to VGA bitplanes
 ;
-; FS:SI -> packed pixel string
+; DS:SI -> packed pixel string
 ; BP    -> pixel count (multiple of 8)
 ; ES:DI -> output
 ;
@@ -214,7 +176,7 @@ packedpixel2vga:
 		mov cx,8
 .loop2:
 		xchg cx,bx
-		fs lodsb
+		lodsb
 		shr al,cl
 		rcl ch,1	; VGA is bigendian.  Sigh.
 		xchg cx,bx
@@ -347,12 +309,15 @@ linear_color	db 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0
 UsingVGA	db 0
 
 		section .bss1
-		alignb 2
+		alignb 4
+LSSHeader	equ $
+LSSMagic	resd 1			; Magic number
 GraphXSize	resw 1			; Width of splash screen file
+GraphYSize	resw 1			; Height of splash screen file
+GraphColorMap	resb 3*16
 VGAPos		resw 1			; Pointer into VGA memory
-VGACluster	resw 1			; Cluster pointer for VGA image file
 VGAFilePtr	resw 1			; Pointer into VGAFileBuf
-TextColorReg	resb 17			; VGA color registers for text mode
+; TextColorReg	resb 17			; VGA color registers for text mode
 %if IS_SYSLINUX
 VGAFileBuf	resb FILENAME_MAX+2	; Unmangled VGA image name
 %else
@@ -360,3 +325,7 @@ VGAFileBuf	resb FILENAME_MAX	; Unmangled VGA image name
 %endif
 VGAFileBufEnd	equ $
 VGAFileMBuf	resb FILENAME_MAX	; Mangled VGA image name
+
+; We need a buffer of 640+80 bytes.  At this point, command_line should
+; not be in use, so use that buffer.
+VGARowBuffer	equ command_line
diff --git a/isolinux.asm b/isolinux.asm
index e485532d..649bfe01 100644
--- a/isolinux.asm
+++ b/isolinux.asm
@@ -197,17 +197,6 @@ _spec_len	equ _spec_end - _spec_start
 		alignb open_file_t_size
 Files		resb MAX_OPEN*open_file_t_size
 
-;
-; Constants for the xfer_buf_seg
-;
-; The xfer_buf_seg is also used to store message file buffers.  We
-; need two trackbuffers (text and graphics), plus a work buffer
-; for the graphics decompressor.
-;
-xbs_textbuf	equ 0			; Also hard-coded, do not change
-xbs_vgabuf	equ trackbufsize
-xbs_vgatmpbuf	equ 2*trackbufsize
-
 		section .text
 ;;
 ;; Primary entry point.  Because BIOSes are buggy, we only load the first
diff --git a/keywords.inc b/keywords.inc
index 672c6312..e98f879c 100644
--- a/keywords.inc
+++ b/keywords.inc
@@ -47,10 +47,10 @@ keywd_size	equ 8	; Bytes per keyword
 keywd_table:
 		keyword menu,		pc_comment
 		keyword text,		pc_text
-		keyword include,	pc_filecmd,	pc_include
+		keyword include,	pc_opencmd,	pc_include
 		keyword append,		pc_append
 		keyword default,	pc_default
-		keyword display,	pc_filecmd,	get_msg_file
+		keyword display,	pc_opencmd,	get_msg_file
 		keyword font,		pc_filecmd,	loadfont
 		keyword implicit,	pc_setint16,	AllowImplicit
 		keyword kbdmap,		pc_filecmd,	loadkeys
diff --git a/ldlinux.asm b/ldlinux.asm
index 217fb15d..0c5c94f8 100644
--- a/ldlinux.asm
+++ b/ldlinux.asm
@@ -132,18 +132,6 @@ ClustByteShift	resb 1			; Shift count for bytes/cluster
 		alignb open_file_t_size
 Files		resb MAX_OPEN*open_file_t_size
 
-;
-; Constants for the xfer_buf_seg
-;
-; The xfer_buf_seg is also used to store message file buffers.  We
-; need two trackbuffers (text and graphics), plus a work buffer
-; for the graphics decompressor.
-;
-xbs_textbuf	equ 0			; Also hard-coded, do not change
-xbs_vgabuf	equ trackbufsize
-xbs_vgatmpbuf	equ 2*trackbufsize
-
-
 		section .text
 ;
 ; Some of the things that have to be saved very early are saved
diff --git a/parseconfig.inc b/parseconfig.inc
index 1530e5cb..739a884b 100644
--- a/parseconfig.inc
+++ b/parseconfig.inc
@@ -145,23 +145,34 @@ pc_setint16:
 
 ;
 ; Generic file-processing commands:
-; "display", "font", "kbdmap", "include"
+; "font", "kbdmap",
 ;
 pc_filecmd:	push ax				; Function to tailcall
 		call pc_getline
 		mov di,MNameBuf
 		call mangle_name
-		call searchdir			; tailcall
+		call searchdir
 		jnz .ok
 		pop ax				; Drop the successor function
 .ok:		ret				; Tailcall if OK, error return
 
 ;
-; "include" command (invoked from pc_filecmd)
+; Commands that expect the file to be opened on top of the getc stack.
+; "display", "include"
 ;
-pc_include:	call openfd
-		jz .err
-		inc word [IncludeLevel]
+pc_opencmd:	push ax				; Function to tailcall
+		call pc_getline
+		mov di,MNameBuf
+		call mangle_name
+		call open
+		jnz .ok
+		pop ax				; Drop the successor function
+.ok:		ret				; Tailcall if OK, error return
+
+;
+; "include" command (invoked from pc_opencmd)
+;
+pc_include:	inc word [IncludeLevel]
 .err:		ret
 
 ;
diff --git a/pxelinux.asm b/pxelinux.asm
index a015c3ff..f52b787a 100644
--- a/pxelinux.asm
+++ b/pxelinux.asm
@@ -242,17 +242,6 @@ pxe_unload_stack_pkt_len	equ $-pxe_unload_stack_pkt
 packet_buf	resb 2048		; Transfer packet
 packet_buf_size	equ $-packet_buf
 
-;
-; Constants for the xfer_buf_seg
-;
-; The xfer_buf_seg is also used to store message file buffers.  We
-; need two trackbuffers (text and graphics), plus a work buffer
-; for the graphics decompressor.
-;
-xbs_textbuf	equ 0			; Also hard-coded, do not change
-xbs_vgabuf	equ trackbufsize
-xbs_vgatmpbuf	equ 2*trackbufsize
-
 		section .text
 		;
 		; PXELINUX needs more BSS than the other derivatives;
diff --git a/ui.inc b/ui.inc
index ffc18e39..7e5ac112 100644
--- a/ui.inc
+++ b/ui.inc
@@ -186,11 +186,9 @@ show_help:	; AX = func key # (0 = F1, 9 = F10, 11 = F12)
 		xchg di,ax
 		cmp byte [di+NULLOFFSET],NULLFILE
 		je short fk_nofile		; Undefined F-key
-		call searchdir
+		call open
 		jz short fk_nofile		; File not found
-		push si
 		call crlf
-		pop si
 		call get_msg_file
 		jmp short fk_wrcmd