core: Reimplement writestr in C

Implement writestr in C instead of asm and move writestr.inc into
modules/ because it's required by modules/ver.asm.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>

6 files changed, 77 insertions, 96 deletions

diff --git a/core/isolinux.asm b/core/isolinux.asm
index b0b21a3b..8757c0fa 100644
--- a/core/isolinux.asm
+++ b/core/isolinux.asm
@@ -286,7 +286,7 @@ initial_csum:	xor edi,edi
 		call writemsg
 		mov al,dl
 		call writehex2
-		call crlf
+		call crlf_early
 %endif
 		;
 		; Initialize spec packet buffers
@@ -326,7 +326,7 @@ initial_csum:	xor edi,edi
 		call writemsg
 		mov al,byte [sp_drive]
 		call writehex2
-		call crlf
+		call crlf_early
 %endif
 
 found_drive:
@@ -393,7 +393,7 @@ found_file:
 		mov si,offset_msg
 		call writemsg
 		call writehex8
-		call crlf
+		call crlf_early
 %endif
 
 		; Load the rest of the file.  However, just in case there
@@ -623,7 +623,7 @@ spec_query_failed:
 		call writemsg
 		mov al,dl
 		call writehex2
-		call crlf
+		call crlf_early
 
 		cmp byte [sp_drive],dl
 		jne .maybe_broken
@@ -667,7 +667,7 @@ spec_query_failed:
 		call writemsg
 		mov al,dl
 		call writehex2
-		call crlf
+		call crlf_early
 		mov si,trysbm_msg
 		call writemsg
 		jmp .found_drive		; Pray that this works...
@@ -690,6 +690,26 @@ writemsg:	push ax
 		pop ax
 		ret
 
+writestr_early:
+		pushfd
+		pushad
+.top:		lodsb
+		and al,al
+		jz .end
+		call writechr
+		jmp short .top
+.end:		popad
+		popfd
+		ret
+
+crlf_early:	push ax
+		mov al,CR
+		call writechr
+		mov al,LF
+		call writechr
+		pop ax
+		ret
+
 ;
 ; Write a character to the screen.  There is a more "sophisticated"
 ; version of this in the subsequent code, so we patch the pointer
@@ -1004,7 +1024,7 @@ xint13:		mov byte [RetryCount],retry_count
 		call writestr_early
 		mov al,dl
 		call writehex2
-		call crlf
+		call crlf_early
 		; Fall through to kaboom
 
 ;
@@ -1016,8 +1036,8 @@ disk_error:
 kaboom:
 		RESET_STACK_AND_SEGS AX
 		mov si,err_bootfailed
-		call writestr
-		call getchar
+		pm_call pm_writestr
+		pm_call pm_getchar
 		cli
 		mov word [BIOS_magic],0	; Cold reboot
 		jmp 0F000h:0FFF0h	; Reset vector address
@@ -1026,8 +1046,6 @@ kaboom:
 ;  Common modules needed in the first sector
 ; -----------------------------------------------------------------------------
 
-%include "writestr.inc"		; String output
-writestr_early	equ writestr
 %include "writehex.inc"		; Hexadecimal output
 
 ; -----------------------------------------------------------------------------
@@ -1106,18 +1124,10 @@ all_read:
 ;
 %include "init.inc"
 
-		; Patch the writechr routine to point to the full code
-		mov di,writechr
-		mov al,0e9h
-		stosb
-		mov ax,writechr_full-2
-		sub ax,di
-		stosw
-
 ; Tell the user we got this far...
 %ifndef DEBUG_MESSAGES			; Gets messy with debugging on
 		mov si,copyright_str
-		call writestr_early
+		pm_call pm_writestr
 %endif
 
 ;
diff --git a/core/pxelinux.asm b/core/pxelinux.asm
index 8a95d1e9..178e3545 100644
--- a/core/pxelinux.asm
+++ b/core/pxelinux.asm
@@ -343,7 +343,7 @@ kaboom:
 		pop cx
 		loop .wait1
 .keypress:
-		call crlf
+		pm_call crlf
 		mov word [BIOS_magic],0	; Cold reboot
 		jmp 0F000h:0FFF0h	; Reset vector address
 
diff --git a/core/rawcon.inc b/core/rawcon.inc
deleted file mode 100644
index f0d434c8..00000000
--- a/core/rawcon.inc
+++ /dev/null
@@ -1,75 +0,0 @@
-;
-; writechr:	Write a single character in AL to the console without
-;		mangling any registers.  This does raw console writes,
-;		since some PXE BIOSes seem to interfere regular console I/O.
-;
-%if IS_ISOLINUX
-writechr_full:
-%else
-writechr:
-%endif
-		pushfd
-		push ds
-		push cs
-		pop ds
-		test byte [UsingVGA], 08h
-		jz .videook
-		call vgaclearmode
-.videook:
-		call write_serial	; write to serial port if needed
-		test byte [DisplayCon],01h	; Write to screen?
-		jz .nothing
-
-		pushad
-		mov bh,[BIOS_page]
-		push ax
-                mov ah,03h              ; Read cursor position
-                int 10h
-		pop ax
-		cmp al,8
-		je .bs
-		cmp al,13
-		je .cr
-		cmp al,10
-		je .lf
-		push dx
-                mov bh,[BIOS_page]
-		mov bl,07h		; White on black
-		mov cx,1		; One only
-		mov ah,09h		; Write char and attribute
-		int 10h
-		pop dx
-		inc dl
-		cmp dl,[VidCols]
-		jna .curxyok
-		xor dl,dl
-.lf:		inc dh
-		cmp dh,[VidRows]
-		ja .scroll
-.curxyok:	mov bh,[BIOS_page]
-		mov ah,02h		; Set cursor position
-		int 10h
-.ret:		popad
-.nothing:
-		pop ds
-		popfd
-		ret
-.scroll:	dec dh
-		mov bh,[BIOS_page]
-		mov ah,02h
-		int 10h
-		mov ax,0601h		; Scroll up one line
-		mov bh,[ScrollAttribute]
-		xor cx,cx
-		mov dx,[ScreenSize]	; The whole screen
-		int 10h
-		jmp short .ret
-.cr:		xor dl,dl
-		jmp short .curxyok
-.bs:		sub dl,1
-		jnc .curxyok
-		mov dl,[VidCols]
-		sub dh,1
-		jnc .curxyok
-		xor dh,dh
-		jmp short .curxyok
diff --git a/core/writestr.c b/core/writestr.c
new file mode 100644
index 00000000..66d126af
--- /dev/null
+++ b/core/writestr.c
@@ -0,0 +1,46 @@
+/*
+ * -----------------------------------------------------------------------
+ *
+ *   Copyright 1994-2008 H. Peter Anvin - All Rights Reserved
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
+ *   Boston MA 02111-1307, USA; either version 2 of the License, or
+ *   (at your option) any later version; incorporated herein by reference.
+ *
+ * -----------------------------------------------------------------------
+ *
+ *
+ * writestr.c
+ *
+ * Code to write a simple string.
+ */
+#include <com32.h>
+
+/*
+ * crlf: Print a newline
+ */
+void crlf(void)
+{
+	writechr('\r');
+	writechr('\n');
+}
+
+/*
+ * writestr: write a null-terminated string to the console, saving
+ *            registers on entry.
+ *
+ * Note: writestr_early and writestr are distinct in
+ * SYSLINUX and EXTLINUX, but not PXELINUX and ISOLINUX
+ */
+void writestr(char *str)
+{
+	while (*str)
+		writechr(*str++);
+}
+
+void pm_writestr(com32sys_t *regs)
+{
+	writestr(MK_PTR(regs->ds, regs->esi.w[0]));
+}
diff --git a/modules/ver.asm b/modules/ver.asm
index 8ef63faf..600def02 100644
--- a/modules/ver.asm
+++ b/modules/ver.asm
@@ -565,7 +565,7 @@ is_zf:
 		ret
 
 %include "../core/macros.inc"		; CR/LF
-%include "../core/writestr.inc"		; String output
+%include "writestr.inc"			; String output
 %include "../core/writehex.inc"		; Hexadecimal output
 %include "../core/writedec.inc"		; Decimal output
 
diff --git a/core/writestr.inc b/modules/writestr.inc
index 9c11b320..9c11b320 100644
--- a/core/writestr.inc
+++ b/modules/writestr.inc