
; Public Domain

; test install command: install; r; rdumpidx uninstall
; test run command: ; .; .

%include "lmacros3.mac"
%include "eld.mac"
%include "eldcall.mac"
%include "elddata.mac"

	cpu 8086

	addsection RELOCATEDDATA, nobits vstart=_ELD_RELOC_VSTART
relocateddata:

	addsection HEADER, start=0

	istruc ELD_HEADERX
at eldhxHeader
		; ELD executable header
	istruc ELD_HEADER
at eldhSignature,	db "ELD1"
			db 0,0,0
			db 26
at eldhCodeOffset,	dd CODEOFFSET
at eldhCodeImageLength,	dw code_size
at eldhCodeAllocLength,	dw 0
at eldhDataOffset,	dd DATAOFFSET
at eldhDataImageLength,	dw data_size
at eldhDataAllocLength,	dw total_data_size - data_size
at eldhCodeEntrypoint,	dw linker - code
at eldhReserved
at eldhExtensionSize,	dw header_extension_end - $$
	iend
at eldhxDescriptionOffset,	dd description
at eldhxHelpOffset,		dd DATAOFFSET + msg.help - datastart
header_extension_end:
	iend

description:		asciz "Dump a text byte at DS:SI and ES:DI in 16-bit 86 Mode R dump."


	align 16, db 0

CODEOFFSET equ $ - $$
	addsection CODE, follows=HEADER vstart=_ELD_CODE_VSTART
%define CODEFIXUP - code + 0
code:
		; ELD instance header
	istruc ELD_INSTANCE
at eldiStartCode
at eldiEndCode
at eldiStartData
at eldiEndData
at eldiIdentifier,	fill 8, 32, db "RDumpIdx"
at eldiListing,		asciz _ELD_LISTING
	iend


command:
	jmp strict short .entry
.chain:
	extcall cmd3_not_ext, required	; must NOT be extcallcall
	times 10 - ($ - command) nop
.entry:
	push si
	cmp al, '-'
	jne @F
	extcallcall skipcomma
@@:
	dec si

	mov dx, msg.rdumpidx
internaldatarelocation
	extcallcall isstring?
	je .ours
	pop si
	dec si
	lodsb
	jmp .chain

.ours:
	pop ax
	extcallcall skipcomma
	dec si
reloc2	mov word [relocateddata], relocateddata
linkdatarelocation lastcmd, -4
linkdatarelocation dmycmd
	mov dx, relocateddata
linkdatarelocation msg.uninstall
	extcallcall isstring?
	je uninstall
	lodsb
	extcallcall chkeol
	extcallcall cmd3


puts_handler:
.:
	jmp strict short .entry
.chain:
	extcall puts_ext_done, required	; must NOT be extcallcall
	times 10 - ($ - .) nop
.entry:

		; es:dx -> message
		; ax = length
	push si
	push di
	push ax
	push es
	push dx
	push ds
	 push es
	 pop ds

	mov si, dx

	call ispm
	jz .notours

	cmp ax, 8 * 8 - 1
	jb .notours

	cmp word [si], "AX"
	jne .notours
	cmp byte [si + 2], '='
	jne .notours

	lea bx, [si + 3 + 4]
	mov cx, ax
	sub cx, 3 + 4
@@:
	cmp byte [bx], 32
	je @F
	inc bx
	loop @B
	jmp .notours

@@:
	cmp word [bx + 1], "BX"
	jne .notours
	cmp byte [bx + 1 + 2], '='
	jne .notours

	mov bx, si
	add bx, ax
	cmp word [bx - 2], 13 | (10 << 8)
	jne .notours

	push ss
	pop es
	mov di, buffer
internaldatarelocation

	mov al, 32
	stosb

	mov al, 'S'
	mov si, word [ss:relocateddata]
linkdatarelocation reg_esi
	mov ds, word [ss:relocateddata]
linkdatarelocation reg_ds
	call store

	mov al, 'D'
	mov si, word [ss:relocateddata]
linkdatarelocation reg_edi
	mov ds, word [ss:relocateddata]
linkdatarelocation reg_es
	call store

	mov ax, 13 | (10 << 8)
	stosw
	sub di, strict word buffer
internaldatarelocation
	mov word [ss:length], di
internaldatarelocation

	pop ds
	pop dx
	pop es
	pop ax
	pop di
	pop si

	dec ax
	dec ax				; do not write CR LF

	mov cx, .chain			; -> our chaining entry
internalcoderelocation
	clc
	extcallcall puts_ext_next	; call subsequent puts handlers

	push es
	 push ss
	 pop es
	mov dx, buffer			; es:dx -> message
internaldatarelocation
@@:
	mov ax, word [ss:length]
internaldatarelocation
					; ax = length
	mov cx, .chain			; -> our chaining entry
internalcoderelocation
	clc
	extcallcall puts_ext_next	; call subsequent puts handlers
	pop es

	stc
	extcall puts_ext_done, required
					; directly jump back to debugger, CY

.notours:
	pop ds
	pop dx
	pop es
	pop ax
	pop di
	pop si

	clc
	jmp .chain			; chain if to display -->


store:
	push ax
	mov al, 32
	stosb
	pop ax
	mov ah, 'I'
	stosw
	mov al, '='
	stosb
	lodsb
	cmp al, 32
	jb .dot_or_table
	cmp al, 7Fh
	jae .dot_or_table
	cmp al, "'"
	jne @F
	mov ax, '"' | ("'" << 8)
	stosw
	stosb
	retn

@@:
	push ax
	mov al, "'"
	stosb
	pop ax
	stosb
	mov al, "'"
	db __TEST_IMM16		; (skip mov)
.dot:
	mov al, '.'
	stosb
	retn

.dot_or_table:
	mov bx, relocateddata
linkdatarelocation asciitablenames, -2, optional
	test bx, bx
	jz .dot
	cmp al, 7Fh
	jb .table
	mov al, 32
	je .table
	inc ax
.table:
	mov ah, 0
	add bx, ax
	add ax, ax
	add bx, ax
	mov ax, [ss:bx]
	stosw
	mov al, [ss:bx + 2]
	stosb
	retn


uninstall:
	lodsb
	extcallcall chkeol

	call get_es_ext

	push es
	pop ds

	mov si, hooktable
internaldatarelocation
	lframe
	lenter
	lvar word, table
	 push si

.loop_table:
	rol byte [ss:si + htInstalled], 1
	jnc .next_table
	xor bx, bx		; = 0 (no prior, modify handler)
	mov di, word [ss:si + htEntry]	; di -> us
	mov si, word [ss:si + htHandler]; -> handler
	mov si, word [ss:si]	; si -> first
	test si, si		; none installed ?
	jz .error		; error -->

.loop:
	cmp di, si		; found ?
	je .bx			; yes, use bx -->
	mov bx, si		; bx -> prior handler
	lodsw			; skip entrypoint jmp strict short
	lodsb			; get first byte of chainer
	cmp al, 0E9h		; expecting jmp near ?
	jne .error		; no, error -->
	lodsw			; get rel16 displacement
	add si, ax		; -> next handler
	jmp .loop

.bx:
	test bx, bx		; any prior ?
	jnz .bxnz		; yes -->
	scasw			; skip entrypoint jmp strict short
	cmp byte [di], 0E8h	; is it a call to cmd3_not_ext ?
	jne @F			; no -->
				; yes, reset ext_command_handler to zero
.setbx:
	mov si, word [bp + ?table]
	mov si, word [ss:si + htHandler]; -> handler
	mov word [ss:si], bx
	jmp .done

@@:
	cmp byte [di], 0E9h	; validate
	jne .error		; failure -->
	inc di			; -> rel16 displacement
	mov bx, word [di]	; get displacement
	scasw			; -> after jmp near
	add bx, di		; -> next handler
	jmp .setbx		; set ext_command_handler to next

.bxnz:
	mov si, bx		; -> prior handler with us as downlink
	xchg di, si		; si -> ours, di -> prior
	cmpsw			; skip entrypoint jmp strict short
	movsb			; copy 0E8h/0E9h
	lodsw			; ax = near rel16 displacement
	add ax, si		; add in our base (= absolute offset)
	sub ax, di
	dec ax
	dec ax			; subtract new base (= relative displacement)
	stosw			; store new rel16 displacement
	movsw			; jmp strict short
	movsw			; linkcall target
	movsb			; trailer
.done:
	mov si, word [bp + ?table]
	not byte [ss:si + htInstalled]

.next_table:
	add si, HOOKTABLE_size
	mov word [bp + ?table], si
	cmp si, strict word hooktable_end
internaldatarelocation
	jb .loop_table


	clropt [code + eldiFlags], eldifResident
internalcoderelocation -3	; mark block as free
	mov dx, msg.uninstall_done
internaldatarelocation
@@:
	lleave
	push ss
	pop ds
	extcallcall putsz
	extcallcall cmd3	; return

.error:
	mov ax, 0E01h
	extcallcall setrc
	mov dx, msg.uninstall_error
internaldatarelocation
	jmp @B


get_es_ext:
	mov es, word [relocateddata]
linkdatarelocation extdssel
	extcallcall ispm
	jz @F
	mov es, word [relocateddata]
linkdatarelocation extseg
@@:
	retn


	eldcall_dump_callcall ELDCALL_CALLCALL_LIST

endinstalled equ ($ + CODEFIXUP + 15) & ~15


start:
	mov bx, es
	 push ss
	 pop es
	call skipcomma
	dec si
	mov dx, relocateddata
linkdatarelocation msg.install
	call isstring?
	je install
	mov dx, msg.help
internaldatarelocation
	extcall putsz
	call uninstall_oneshot
	xor ax, ax
	retf


uninstall_oneshot:
	testopt [ss:relocateddata], 1
linkdatarelocation options7, -3
	jnz @F

	mov ax, word [cs:code + eldiEndCode]
internalcoderelocation
	sub ax, word [cs:code + eldiStartCode]
internalcoderelocation
	sub word [relocateddata], ax
linkdatarelocation extseg_used

	mov ax, word [cs:code + eldiEndData]
internalcoderelocation
	sub ax, word [cs:code + eldiStartData]
internalcoderelocation
	sub word [relocateddata], ax
linkdatarelocation extdata_used
@@:
	retn


DATAOFFSET equ CODEOFFSET + code_size
	addsection DATA, follows=CODE vstart=_ELD_DATA_VSTART
%define DATAFIXUP - datastart + 0
datastart:

	struc HOOKTABLE
htEntry:		resw 1
htHandler:		resw 1
htInstalled:		resw 1
	endstruc

	align 2, db 0
hooktable:
		; command last so uninstall abort will leave command installed
	istruc HOOKTABLE
at htEntry,		dw puts_handler
internalcoderelocation
at htHandler,		dw relocateddata
linkdatarelocation ext_puts_handler
at htInstalled,		dw 0
	iend
	istruc HOOKTABLE
at htEntry,		dw command
internalcoderelocation
at htHandler,		dw relocateddata
linkdatarelocation ext_command_handler
at htInstalled,		dw 0
	iend
hooktable_end:

	align 2, db 0

msg:
.rdumpidx:		asciz "RDUMPIDX"
.uninstall_done:	db "RDumpIdx uninstalled."
%if _ELD_RECLAIM_HINT
			db " (Don't forget to use reclaim.eld)"
%endif
			asciz 13,10
.uninstall_error:	asciz "RDumpIdx unable to uninstall!",13,10

uinit_data: equ $

.installed:	asciz "RDumpIdx installed.",13,10
.help:		db "Install this ELD using an INSTALL keyword.",13,10
		db 13,10
		db "16-bit Real/Virtual 86 Mode register dump will have an additional",13,10
		db "two columns at the end listing text pointed to by DS:SI and ES:DI.",13,10
		db 13,10
		db "Run with RDUMPIDX UNINSTALL to uninstall.",13,10
		asciz


	align 16, db 0
init_data_end:
data_size equ $ - datastart
transient_data_size equ data_size

	absolute uinit_data

	alignb 2
length:		resw 1
buffer:		resb 32

	alignb 16
uinit_data_end:
resident_data_end:
resident_data_size equ resident_data_end - datastart

%if uinit_data_end >= init_data_end
 total_data_size equ $ - datastart
%else
 total_data_size equ init_data_end - datastart
%endif
%assign _DATA_SIZE total_data_size


	usesection CODE

install:
	lodsb
	extcall chkeol

	houdini
	mov es, bx		; => ext seg (writable)

	mov ax, endresident - endinstalled
	sub word [es:code + eldiEndCode], ax
internalcoderelocation		; adjust size
	sub word [relocateddata], ax
linkdatarelocation extseg_used	; adjust size

%if (transient_data_size - resident_data_size) > 0
	mov ax, transient_data_size - resident_data_size
	sub word [es:code + eldiEndData], ax
internalcoderelocation		; adjust size
	sub word [relocateddata], ax
linkdatarelocation extdata_used	; adjust size
%endif

	mov si, hooktable_end - HOOKTABLE_size
internaldatarelocation

.loop_table:
	mov bx, word [si + htHandler]; -> handler
	mov bx, word [bx]	; -> prior
	mov di, word [si + htEntry]	; -> our handler
	test bx, bx		; installing as first ?
	jz .only_first		; yes, simple --> (leave as extcall cmd3_not_ext)
	scasw			; skip entrypoint jmp strict short
	mov al, 0E9h		; = jmp near opcode
	stosb			; store
	xchg ax, bx		; ax -> next handler
	sub ax, di
	dec ax
	dec ax			; ax = ax - (di + 2)
	stosw			; store our downlink as rel16 displacement

.only_first:
	mov bx, word [si + htHandler]; -> handler
	mov ax, word [si + htEntry]
	mov word [bx], ax	; -> our entrypoint
	not byte [si + htInstalled]

.next_table:
	sub si, HOOKTABLE_size
	cmp si, strict word hooktable
internaldatarelocation
	jae .loop_table

	setopt [es:code + eldiFlags], eldifResident
internalcoderelocation -3	; mark block as resident

	testopt [relocateddata], 4
linkdatarelocation options7, -3
	jnz @F
	mov dx, msg.installed
internaldatarelocation
	call putsz
@@:
	xor ax, ax
	retf


%include "eldlink.asm"

	align 16
code_size equ $ - code
