debugx: make it work with 16-bit dpmi clients again

DEBUG.TXT

@@ -164,7 +164,7 @@
  the breakpoints may be entered in the usual format ( segment:offset ), they
  are stored internally just as linear addresses, and so BP will display this
  linear address only.
- The type argument is a combined field of bits. Bits 0-1 define the type:
+  The type argument is a combined field of bits. Bits 0-1 define the type:
 
   0 code breakpoint
   1 write watchpoint
@@ -177,15 +177,17 @@
   1 word access
   3 dword access
 
- If no type argument is given, a code breakpoint is assumed. Note that I/O
+  If no type argument is given, a code breakpoint is assumed. Note that I/O
  watchpoints may be rejected by the DPMI host; in any case they require
  bit DE to be set in register CR4.
+  To be able to continue the program after a breakpoint has been hit (without
+ to clear the breakpoint), the debugger will set the Resume flag ( bit 16 in
+ the EFlags register ). Be aware that not all DPMI hosts will reliably preserve
+ that flag when an interrupt occurs, thus making it appear as if the program
+ cannot continue.
 
  Command BC is used to clear a previously set breakpoint.
 
- WinNT platforms and DosEmu don't allow access to the debug registers, hence
- BP/BC are inactive there.
-
  Syntax: BP [[address] type]
          BC bp#
  ---]
@@ -872,7 +874,9 @@
  real-mode - it is a bimodal application, in this regard rather unique.
  While the debugger is active in protected-mode, it may display faults
  that happen when one tries to display memory that is inaccessible; 
- such faults usually can be safely ignored.
+ such faults usually can be safely ignored. However, on NT platforms
+ the debugger isn't notified of page faults - instead, the DOS session
+ usually just will be terminated.
 
   As it has been mentioned at the Q command: when the debuggee is in
  protected-mode, the behavior of DebugX's Q command differs from that

HISTORY.TXT

@@ -95,9 +95,9 @@
        - DebugX: several bugfixes for A and U handling 32bit code segments.
        - bugfix: U split lines if instruction size exceeded 6.
        - bugfix: M didn't work with "upper bound" ranges.
-       - DebugX change: in 32bit code segments, U displayed ECX as first
-         operand for LOOPx to indicate that ECX is used instead of CX.
-         Now a 'D' is attached to the opcode (LOOPxD, x=Z|NZ|E|NE) instead.
+       - DebugX change: the 32-bit variant of the LOOPx instruction was
+         indicated by displaying ECX as first operand. Now a suffix (W/D)
+         is attached to the opcode instead.
        - bugfix: A didn't choose the short (=signed) form of arith
          instructions (adc, add, ...) if E/AX was first operand.
     1.10 [25 January 2008]
@@ -318,6 +318,8 @@
        - fix a cmd: regression since v1.18: "call/jmp [mem_ref]" without a size
          given did default to a far call/jmp.
        - fix u cmd: operand size prefix 66h for 8/16/32-bit relative jmps.
+       - fix a cmd: NEar qualifier was accepted/ignored for immediate far
+         jmp/call.
        - u cmd, call far [mem]: qualifiers "FAR"/"DWORD FAR" changed to
          "FAR16"/"FAR32".
        - DebugR(L): Q cmd may be activated for this variant.

Test/TEST1.SCR

@@ -0,0 +1,18 @@
+
+; test a(ssemble) cmd
+
+a
+mov cx,1
+movzx cx,cl
+movzx ecx,cl
+mov cx,[0]
+movzx cx,[0]
+movzx ecx,[0]	; should be an error
+movzx ecx,wo [0]
+call far 0:0
+call ne 0       ; should be ok
+cmp [0],0       ; should be an error
+cmp wo [0],0
+
+u 100 l 30
+q

src/ASMTBL.INC

@@ -83,14 +83,14 @@ oplists label byte
 	opl 49,OP_DR, OP_32+OP_R_MOD	; idx=73, ofs=D0h
 	opl 4A,OP_32+OP_R_MOD, OP_TR	; idx=74, ofs=D3h
 	opl 4B,OP_TR, OP_32+OP_R_MOD	; idx=75, ofs=D6h
-if MMXSUPP
+ife MMXSUPP
+ASMMOD	EQU 76
+else
 	opl 4C,OP_MMX, OP_32+OP_RM	; idx=76, ofs=D9h
 	opl 4D,OP_32+OP_RM, OP_MMX	; idx=77, ofs=DCh
 	opl 4E,OP_MMX, OP_64+OP_RM	; idx=78, ofs=DFh
 	opl 4F,OP_64+OP_RM, OP_MMX	; idx=79, ofs=E2h
-ASMMOD	EQU 50h
-else
-ASMMOD	EQU 4Ch
+ASMMOD	EQU 80
 endif
 
 ;--- Assembler: data on groups.

src/DEBUG.ASM

@@ -47,7 +47,7 @@
 ;       - better syntax checks for A (so i.e. "mov ax,al" is rejected)
 ;       - add MMX instructions for A and U
 ;       - support loading *.HEX files
-;       - hide debug's IVT vectors 0,1,3? Alternately, init them only when the
+;       - hide debug's IVT vectors 0,1,3 for d(i)? Alternately, init them only when the
 ;         first G/P/T cmd is run, like MS Debug does for 1 & 3?
 
 VERSION    textequ <2.03>
@@ -93,7 +93,8 @@ DGCMD      = 0		; support DG cmd
 DICMD      = 0		; support DI cmd
 DLCMD      = 0		; support DL cmd
 DMCMD      = 1		; support DM cmd
-DPCMD      = 0		; support DP cmd
+DPCMD      = 0		; support DP cmd (dump partition)
+DPCMDR0    = 0		; support DP cmd (dump paging table, ring0 only)
 DTCMD      = 0		; support DT cmd
 DXCMD      = 0		; support DX cmd
 QCMD       = 1		; support Q cmd
@@ -207,6 +208,7 @@ CATCHINT0C = 0
  endif
 CATCHINT0D = 1
 CATCHINT41 = 0
+DPCMDR0    = 0
 LCMD       = 0
 QCMD       = 0	; may be set to 1
 WCMD       = 0
@@ -1049,6 +1051,8 @@ if DMCMD
 endif
 if DPCMD
 	db 'dump partitions', TAB, 'DP physical_disk',CR,LF
+elseif DPCMDR0
+	db 'dump page table', TAB, 'DP [linear_address]',CR,LF
 endif
 if DTCMD
 	db 'dump TSS', TAB, 'DT',CR,LF
@@ -1561,6 +1565,7 @@ initdpmi proc
 	pop edx
 	.286
 	adc al,0
+	jz @F
 	mov cl, 66h
 	mov ah, 4
 @@:
@@ -2189,11 +2194,52 @@ cc2:
 	ret
 c_cmd endp
 
-if DPCMD
+if DPCMD or DPCMDR0
+
+dp_cmd proc
+
+ if DPCMDR0
+
+	.386
+ 
+CONST segment
+szCr3 db "CR3=",0
+szMappedCr3 db ", mapped at ",0
+CONST ends
+
+	mov si, offset szCr3
+	call copystring
+	mov eax, cr3
+	call hexdword
+	mov esi, cr3
+	and si, 0F000h	;esi=physical address
+	mov cx, 4	; cx=size in bytes
+	mov ax, 2	; return linear address (in esi) of physical region
+
+;--- callout int 22h requires to set the host ring0 stack!
+
+	mov bp, sp
+	mov dx, ss
+	lss esp, [r0SSEsp]
+	int 22h		; win396 debugger interface
+	mov ss, dx
+	mov sp, bp
+
+	cmp ax, 1
+	jnz exit
+	push esi
+	mov si, offset szCr3
+	call copystring
+	pop eax
+	call hexdword
+exit:
+	call putsline
+	ret
+
+ else
 
 ;--- DP disk - display partition table of a fixed disk
 
-dp_cmd proc
 	call getbyte		;get byte into DL
 	call chkeol			;expect end of line here
 	mov bp, sp
@@ -2242,6 +2288,7 @@ error:
 	mov sp, bp
 	call int21ah9
 	ret
+ endif
 dp_cmd endp
 endif
 
@@ -3131,7 +3178,7 @@ dcmds label byte
 	@condcmd DICMD,'i',di_cmd
 	@condcmd DLCMD,'l',dgl_cmd
 	@condcmd DMCMD,'m',dm_cmd
-	@condcmd DPCMD,'p',dp_cmd
+	@condcmd DPCMD or DPCMDR0,'p',dp_cmd
 	@condcmd DTCMD,'t',dt_cmd
 	@condcmd DXCMD,'x',dx_cmd
 size_dcmds equ ($ - offset dcmds) / 3

src/LINEASM.INC

@@ -1,6 +1,11 @@
 
 ;--- A command - tiny assembler.
 
+;--- todo:
+;--- 1. fix regression since v1.09: cmp [x], yy  assumes word operand if no size given
+;--- 2. MS debug accepts call near/far [x], Debug rejects near [x], accepts far [x]
+;--- 3. MS debug accepts call near/far x (adding current cs as seg if far), Debug rejects both
+
 ;--- macros for asmtbl.inc
 
 ;--- mne macro, used for the assembler mnemonics table
@@ -54,6 +59,7 @@ endm
 ;--- opl macro, used to define operand list types
 ;--- the macro defines an EQUate, OPLIST_XX, which
 ;--- is refered to by array opindex.
+;--- v2.03: "terminating" 0 no longer required.
 
 opl macro index, value:VARARG
 OPLIST_&index equ $ - oplists
@@ -90,8 +96,9 @@ OP_AX		equ 14		;al or ax or eax
 ;--- order must match items in asm_jmp1, bittab and dis_optab.
 ;--- additionally, order of OP_M64 - OP_FARMEM is used
 ;--- in table asm_siznum
+;--- v2.03: value 0 was used to terminate an operand list ( macro opl )
+;---        it's free now.
 
-;--- value 0 is used to terminate an operand list ( see macro opl )
 OP_M64		equ 2		; 0 qword memory (obsolete?)
 OP_MFLOAT	equ 4		; 1 float memory
 OP_MDOUBLE	equ 6		; 2 double-precision floating memory
@@ -953,6 +960,13 @@ ab14:
 	jg ab17			;if we can't have a colon here
 	cmp al,':'
 	jne ab17		;if not xxxx:yyyy
+if 1	;v2.03: size for ssss:oooo must be none or far
+	cmp [di].OPRND.sizearg, SIZ_NONE
+	jz @F
+	cmp [di].OPRND.sizearg, SIZ_FAR
+	jnz ab24
+@@:
+endif
 	call skipwhite
 	call aageti
 	mov cx,word ptr [di].OPRND.num+0
@@ -1317,7 +1331,7 @@ ac06:               ;<--- next operand
 ;	shr al,cl		;move bits 0-3 back
 	db 0d4h,10h		;=aam 10h (AX=00XY -> AX=0X0Y)
 	mov [ai.reqsize],ah	;save size away
-	@dprintf "ac08: size requested, AH in AX=%X", ax
+	@dprintf "ac08: di=%X size requested, AH in AX=%X", di, ax
 	jmp ac08
 @@:					;AL = OP_M64 - ...
 	add al,ASM_OPOFF - OP_M64	;adjust for the start entries im asm_jmp1
@@ -1327,7 +1341,7 @@ ac08:
 	mov cx,[asm_jmp1+bx] ;subroutine address
 	shr bx,1
 	mov al,[bittab+bx]
-	@dprintf "ac08: si=%X, offset=%X, func=%X, al=%X", si, bx, cx, ax
+	@dprintf "ac08: di=%X si=%X, offset=%X, func=%X, al=%X", di, si, bx, cx, ax
 	test al,[di].OPRND.flags
 	jz ac09			;if no required bits are present
 	call cx			;call its specific routine
@@ -1709,8 +1723,9 @@ aop_ax:
 
 ao07:               ;<--- entry for OP_RM, OP_M, OP_R_MOD, OP_R, OP_R_ADD...
 	or [ai.varflags],VAR_SIZ_NEED
-	mov al,[ai.reqsize]
-	sub al,5		;OP_1632 >> 4
+	@dprintf "ao07: size check, reqsizeB=%X, sizeargB=%X", word ptr ai.reqsize, word ptr [di].OPRND.sizearg
+	mov al,[ai.reqsize]	;4 OP_ALL, 5 OP_1632, 6 OP_8, 7 OP_16, 8 OP_32, 9 OP_64
+	sub al,5
 	jl ao12			;if OP_ALL
 	jz ao13			;if OP_1632
 ;--- OP_8=1, OP_16=2, OP_32=3, OP_64=4

src/TRAPP.INC

@@ -114,7 +114,7 @@ if SAFESS
 endif
 endm
 
-;--- store value of cr2 in exc msg
+;--- store value of cr2/cr3 in exc msg
 rendercr2:
 	cld
 	push es