--- trunk/mkinitrd-magellan/isolinux/com32.inc	2010/08/19 08:27:19	1132
+++ trunk/mkinitrd-magellan/isolinux/com32.inc	2010/08/19 09:50:43	1133
@@ -1,7 +1,6 @@
-;; $Id: com32.inc,v 1.1 2007-09-01 22:44:04 niro Exp $
 ;; -----------------------------------------------------------------------
-;;   
-;;   Copyright 1994-2003 H. Peter Anvin - All Rights Reserved
+;;
+;;   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
@@ -27,12 +26,21 @@
 ; "mov ax,0x4cff; int 0x21" in 16-bit mode.  This will abort the
 ; program with an error if run in 16-bit mode.
 ;
-pm_idt:		equ 0x100000
-pm_entry:	equ 0x101000
+
+		; We need to make this a proper section rather
+		; than using absolute numbers, in order to work
+		; around a bug in GNU ld 2.17, which is still in
+		; use as of this writing in the form of Debian
+		; 4.0 (etch).
+		bits 32
+		section .com32 exec write nobits align=16
+pm_idt		equ 0x100000		; Needs to be absolute...
+		resb 4096
+pm_entry:				; Needs to not be...
 
 		bits 16
 		section .data
-		align 2, db 0
+		alignz 2
 com32_pmidt:
 		dw 8*256		; Limit
 		dd pm_idt		; Address
@@ -44,8 +52,7 @@
 		section .text
 is_com32_image:
 		push si			; Save file handle
-		push dx			; File length held in DX:AX
-		push ax
+		push eax		; Save file length
 
 		call make_plain_cmdline
 		; Copy the command line into the low cmdline buffer
@@ -58,15 +65,18 @@
 		sub cx,si
 		fs rep movsb
 
-		call highmemsize	; We need the high memory size...
+		mov si,KernelCName
+		mov di,Com32Name
+		call strcpy
+
 		call comboot_setup_api	; Set up the COMBOOT-style API
 
 		mov edi,pm_entry	; Load address
 		pop eax			; File length
 		pop si			; File handle
 		xor dx,dx		; No padding
+		mov bx,abort_check	; Don't print dots, but allow abort
 		call load_high
-		call crlf
 
 com32_start:
 		mov ebx,com32_call_start	; Where to go in PM
@@ -75,32 +85,38 @@
 		cli
 		mov ax,cs
 		mov ds,ax
-		mov [SavedSSSP],sp
-		mov [SavedSSSP+2],ss
+		mov [RealModeSSSP],sp
+		mov [RealModeSSSP+2],ss
 		cld
 		call a20_test
 		jnz .a20ok
 		call enable_a20
 
 .a20ok:
+		mov byte [bcopy_gdt.TSS+5],89h	; Mark TSS unbusy
+
 		lgdt [bcopy_gdt]	; We can use the same GDT just fine
 		lidt [com32_pmidt]	; Set up the IDT
 		mov eax,cr0
 		or al,1
 		mov cr0,eax		; Enter protected mode
-		jmp 20h:.in_pm
-		
+		jmp PM_CS32:.in_pm
+
 		bits 32
 .in_pm:
 		xor eax,eax		; Available for future use...
 		mov fs,eax
 		mov gs,eax
+		lldt ax
 
-		mov al,28h		; Set up data segments
+		mov al,PM_DS32		; Set up data segments
 		mov es,eax
 		mov ds,eax
 		mov ss,eax
 
+		mov al,PM_TSS		; Be nice to Intel's VT by
+		ltr ax			; giving it a valid TR
+
 		mov esp,[PMESP]		; Load protmode %esp if available
 		jmp ebx			; Go to where we need to go
 
@@ -110,9 +126,10 @@
 ;
 com32_call_start:
 		;
-		; Point the stack to the end of high memory
+		; Point the stack to the end of (permitted) high memory
 		;
-		mov esp,[word HighMemSize]
+		mov esp,[word HighMemRsvd]
+		xor sp,sp		; Align to a 64K boundary
 
 		;
 		; Set up the protmode IDT and the interrupt jump buffers
@@ -159,12 +176,15 @@
 
 		; Now everything is set up for interrupts...
 
+		push dword Com32Name		; Module filename
+		push dword [HighMemSize]	; Memory managed by Syslinux
+		push dword com32_cfarcall	; Cfarcall entry point
 		push dword com32_farcall	; Farcall entry point
 		push dword (1 << 16)		; 64K bounce buffer
-		push dword (comboot_seg << 4)	; Bounce buffer address
+		push dword (xfer_buf_seg << 4)	; Bounce buffer address
 		push dword com32_intcall	; Intcall entry point
 		push dword command_line		; Command line pointer
-		push dword 5			; Argument count
+		push dword 8			; Argument count
 		sti				; Interrupts OK now
 		call pm_entry			; Run the program...
 		; ... on return, fall through to com32_exit ...
@@ -177,11 +197,11 @@
 		cld
 		mov [PMESP],esp		; Save exit %esp
 		xor esp,esp		; Make sure the high bits are zero
-		jmp 08h:.in_pm16	; Return to 16-bit mode first
+		jmp PM_CS16:.in_pm16	; Return to 16-bit mode first
 
 		bits 16
 .in_pm16:
-		mov ax,18h		; Real-mode-like segment
+		mov ax,PM_DS16		; Real-mode-like segment
 		mov es,ax
 		mov ds,ax
 		mov ss,ax
@@ -200,11 +220,10 @@
 		mov es,ax
 		mov fs,ax
 		mov gs,ax
-		lss sp,[SavedSSSP]	; Restore stack
+		lss sp,[RealModeSSSP]	; Restore stack
 		jmp bx			; Go to whereever we need to go...
 
 com32_done:
-		call disable_a20
 		sti
 		jmp enter_command
 
@@ -227,7 +246,7 @@
 		jmp com32_enter_pm		; Go back to PM
 
 ;
-; 16-bit system call handling code
+; 16-bit intcall/farcall handling code
 ;
 com32_sys_rm:
 		pop gs
@@ -248,7 +267,18 @@
 		push es
 		push fs
 		push gs
-		mov ebx,com32_sys_resume
+		mov ebx,com32_syscall.resume
+		jmp com32_enter_pm
+
+;
+; 16-bit cfarcall handing code
+;
+com32_cfar_rm:
+		retf
+.return:
+		mov sp,[cs:Com32SysSP]
+		mov [cs:RealModeEAX],eax
+		mov ebx,com32_cfarcall.resume
 		jmp com32_enter_pm
 
 ;
@@ -303,10 +333,10 @@
 com32_syscall:
 		cld
 
-		movzx edi,word [word SavedSSSP]
-		movzx ebx,word [word SavedSSSP+2]
+		movzx edi,word [word RealModeSSSP]
+		movzx ebx,word [word RealModeSSSP+2]
 		sub edi,54		; Allocate 54 bytes
-		mov [word SavedSSSP],di
+		mov [word RealModeSSSP],di
 		shl ebx,4
 		add edi,ebx		; Create linear address
 
@@ -330,9 +360,9 @@
 		; On return, the 44-byte return structure is on the
 		; real-mode stack, plus the 10 additional bytes used
 		; by the target address (see above.)
-com32_sys_resume:
-		movzx esi,word [word SavedSSSP]
-		movzx eax,word [word SavedSSSP+2]
+.resume:
+		movzx esi,word [word RealModeSSSP]
+		movzx eax,word [word RealModeSSSP+2]
 		mov edi,[esp+12*4]	; Dest regs
 		shl eax,4
 		add esi,eax		; Create linear address
@@ -343,17 +373,68 @@
 		mov cl,11		; 44 bytes
 		rep movsd		; Copy register block
 
-		add dword [word SavedSSSP],54	; Remove from stack
+		add dword [word RealModeSSSP],54	; Remove from stack
 
 		popad
 		popfd
 		ret			; Return to 32-bit program
 
+;
+; Cfarcall invocation.  We copy the stack frame to the real-mode stack,
+; followed by the return CS:IP and the CS:IP of the target function.
+;
+com32_cfarcall:
+		pushfd
+		pushad
+
+		cld
+		mov ecx,[esp+12*4]		; Size of stack frame
+
+		movzx edi,word [word RealModeSSSP]
+		movzx ebx,word [word RealModeSSSP+2]
+		mov [word Com32SysSP],di
+		sub edi,ecx		; Allocate space for stack frame
+		and edi,~3		; Round
+		sub edi,4*2		; Return pointer, return value
+		mov [word RealModeSSSP],di
+		shl ebx,4
+		add edi,ebx		; Create linear address
+
+		mov eax,[esp+10*4]	; CS:IP
+		stosd			; Save to stack frame
+		mov eax,com32_cfar_rm.return	; Return seg:off
+		stosd
+		mov esi,[esp+11*4]	; Stack frame
+		mov eax,ecx		; Copy the stack frame
+		shr ecx,2
+		rep movsd
+		mov ecx,eax
+		and ecx,3
+		rep movsb
+
+		mov bx,com32_cfar_rm
+		jmp com32_enter_rm
+
+.resume:
+		popad
+		mov eax,[word RealModeEAX]
+		popfd
+		ret
+
 		bits 16
 
-		section .bss
+		section .bss1
 		alignb 4
+RealModeSSSP	resd 1			; Real-mode SS:SP
+RealModeEAX	resd 1			; Real mode EAX
 PMESP		resd 1			; Protected-mode ESP
 Com32SysSP	resw 1			; SP saved during COM32 syscall
 
+		section .uibss
+%if IS_SYSLINUX
+Com32Name	resb FILENAME_MAX+2
+%else
+Com32Name	resb FILENAME_MAX
+%endif
+
 		section .text