rtmload.asm

Dos6.0

	TITLE	RTMLOAD - Runtime module loader
;***
; RTMLOAD - DOS 2/3 Runtime Module Loader
;
;	Copyright <C> 1986, Microsoft Corporation
;
; Purpose:
;	This module is linked to a BASCOM-generated object
;	file created with the RTM option (no /O).  This code
;	will load the RTM EXE directly and place the code in
;	high memory and the data to the compiled program DGROUP.
;	The RTM code will then finish the initialization and
;	start execution of the compiled program.
;
;	This module is also used to load a user libraries EXE file
;	into high memory, along with it's symbol table, for the
;	QB4 interpreter.  QB4 user libraries are very similar to the
;	compiler DOS 3 RTM except that user libraries also contain
;	a symbol table concatenated to the end of the file.
;
;******************************************************************************

INCLUDE	switch.inc
INCLUDE	rmacros.inc			

	USESEG	<_DATA>			

INCLUDE seg.inc				
INCLUDE	addr.inc
INCLUDE baslibma.inc
INCLUDE files.inc			
INCLUDE array.inc			
INCLUDE rtps.inc			
INCLUDE ulib.inc			
INCLUDE const.inc			
INCLUDE string.inc


CondEnd	MACRO	entrypoint		; generate END
	END				
	ENDM				

	CreateSeg	LOADRTM,LOADRTM,BYTE,	PUBLIC, CODE		
	CreateSeg	LOADRTMEND, LOADRTMEND, PARA, PUBLIC, CODE	
	CreateSeg	CODE,	UL_TEXT,BYTE,	PUBLIC, CODE		


INCLUDE idmac.inc			

;	QBI message numbers used to call QBI message mapper

	EXTRN	ER_DMA:ABS		;Dos Arena error
	EXTRN	ER_ULM:ABS		;Memory allocation error
	EXTRN	ER_ULO:ABS		;Out of memory error
	EXTRN	ER_ULI:ABS		;Invalid user library format error
	EXTRN	ER_ULD:ABS		;Disk IO error
	EXTRN	ER_ULF:ABS		;Cannot find file error (if redirected IO)
	EXTRN	ER_ULE:ABS		;Error message preamble
	EXTRN	ER_ULG:ABS		;Error message postamble
	EXTRN	ER_ULP:ABS		;Path prompt preamble
	EXTRN	ER_ULT:ABS		;Path prompt postamble

	externFP B$END			;Quick exit routine
	externFP B$Pause		;Displays - Hit any key to continue
	externFP B$Shell		;QBC Exec helper
	externFP B$ShellSetup		;Prepares runtime for QBC Exec
	externFP B$ShellRecover 	;Recovers state after QBC exec
	externFP B$ULDataRelease	;releases data images
	externFP B$ULTerm		;calls UL terminators
	externFP B$ULGetCommon		;search for compiled common
	externFP B$ITCR 		; print CR-LF 
	externFP OpenCheckDrive		
	externFP FindAndOpenFile
	externFP B$FHAllocFAR		
	externFP B$FHDeallocFAR 	
	externFP __ctermsub		; terminates math and restores
					; divide-by-zero interrupts


INCLUDE	exehdr.inc		;structure for EXE file header area



sBegin	_DATA			
	externW	__psp		;program prefix
	externB bufStdMsg	;QBI message buffer
	externW b$pBC_SAB	;ptr to BC start address table
	externW __asizds	;max DGROUP space
	externW STKHQQ		;C low water mark for stack
	externW __atopsp	;top of allocated stack space
	externW b$pend 	;bottom of allocated stack space
	externW b$pendchk	;low water mark for stack
	externW b$ULSymSeg	;User Library symbol table segment
	externW b$ULDataLength ;length of UL static data
	externW b$ULDataStart	;offset of UL static data in DGROUP
	externW b$FHDStart	;terminating Far heap descriptor
	globalW b$pULVars,0	;address of shared data defined in UL
	externB fDebugScr	; address of shared data defined in UL
	externB b$Buf1		; general purpose filename buffer
	externB qbIniFName	; Literal "qb.ini"
	externW bdExePath	; bd for user-specified exe path
	externW bdLibPath	; bd for user-specified lib path
	externW bdInclPath	;bd for user-specified include path
QBINC	db	'_QB_INC='	;our own environment variable name
	cbQBINC = $ - QBINC	;length of the string

	public	CB_bufPath	
	public	CB_bufLib	

	globalB bufPath,<"PATH">	
	CB_bufPath	=   $ - bufPath 
	globalB bufLib,<"LIB">
	CB_bufLib	=   $ - bufLib	
	globalB bufCurDir,<".\",0>      



sEnd	DATA



assumes	CS,LOADRTM
assumes	DS,LOADRTM
assumes	ES,NOTHING

sBegin	LOADRTM


;	Data for runtime module loader.

EHBuffer	DB	SIZE ExeHeader DUP(?) ;buffer for RTM EXE header

	externNP ListStdMsgRtmNear	;QBI message mapper

ULBuffer	DB	SIZE UserLib_Hdr DUP(?) ;buffer for UL header


ProgramPSP	DW	1 DUP(?)	;PSP of program

RtmCodeSeg	DW	1 DUP(?)	;local copy of code Seg
RtmCodeSize	DW	1 DUP(?)	;size of RTM code

ULSymSeg	DW	1 DUP(?)	;segment of user lib symbol table
ULSymSize	DW	1 DUP(?)	;size of user lib symbol table
DbPub		ULSquishSize		
DbPub		ULCodeSquishSize	
ULSquishSize	DW	1 DUP(?)	;byte count of compressed leading
					;  zeros in QLB, both DATA and CODE
ULCodeSquishSize DW	1 DUP(?)	;byte count of compressed leading
					;  zeros at start of QLB code

ULCheckSum	DW	1 DUP(?)	;check sum for user library
fQBCExec	DB	0		;non-zero if QBC compile in progress
fULQBCReload	DB	0		;non-zero if we need to reload
					;UL because of QBC exec.
fNoIntHooked	DB	0		; non-zero if no interrupts are
					; hooked (during make-exe) and
					; __ctermsub shouldn't be done upon
					; error.

PathEnvPtr	LABEL	DWORD		
RelocBufPtr	LABEL	DWORD

SavedSSinCS	LABEL	WORD		
PathEnvOffset	LABEL	WORD
RelocBufOffset	LABEL	WORD
		DW	1 DUP(?)	;offset to ENV PATH or reloc item

SavedSPinCS	LABEL	WORD		
PathEnvSegment	LABEL	WORD
RelocBufSegment	LABEL	WORD
		DW	1 DUP(?)	;segment to ENV PATH or reloc item

QBCDataBlock	STRUC
	CommandList	DW	?	;Set by UI - psd of commands to exec.
	fErrorCode	DW	?	;Set by Loader - non zero if an error
					;occurred in one of the execs (contains
					;error code returned by the exec.
QBCDataBlock	ENDS

PUBLIC	b$QBCData
b$QBCData	QBCDataBlock<>		;QBCData block - defined in LOADRTM seg


QBExe	DB	'QB.EXE',0		;name of QB interpreter
	EXEExt	EQU OFFSET QBExe + 2	;pts to .EXE extension


	QBExeLength = $ - QBExe 	;length of the file name
LibString	DB	"LIB="		;environment variable for LIB
	LibStringLength = $ - LibString 


Filename	DB	"QB.QLB",0	;default userlib filename
	FilenameLength	= $ - Filename	;length of just the filename
	QLBExt EQU OFFSET Filename + 2	;pts to .QLB extension

;	The following three items are order-dependent.

PUBLIC	b$ULfsd
PUBLIC	b$ULNameLen
PUBLIC	b_ULfsd 			;Interpreter Reachable Label
PUBLIC	b_ULNameLen			;Interpreter Reachable Label

b_ULfsd LABEL	WORD			;Interpreter Reachable Label
b$ULfsd	DW	OFFSET Filename		;Offset of user lib name
		DW	SEG LOADRTM	;Segment of user lib name
b_ULNameLen	LABEL	WORD		;Interpreter Reachable Label
b$ULNameLen	DW	FilenameLength	;Length of user lib name


;
;Definition of Bits for fUserPrompt
;

F_SAVED  = 1 ; We have saved the QLIB name (TRUE) vs not been saved (FALSE)
F_PRPATH = 2 ; We should print path with msgs (TRUE) vs. base name only (FALSE)

fUserPrompt	DB	0		; Flags for loading a file.


;	The following string descriptors are order dependent.

sdNull	DW	szNullLength,OFFSET szNull ;string desc for NULL
sdStack DW	szStackLength,OFFSET szStack ;string desc for STACK
sdSym	DW	szSymLength, OFFSET szSym  ;string desc for SYMBOLS
sdBSA	DW	szBSALength, OFFSET szBSA  ;string desc for BC_SAB


szNull	DB	'NULL',0
	szNullLength = $ - szNull

szStack DB	'STACK',0		
	szStackLength = $ - szStack	

szSym	DB	'SYMBOL',0
	szSymLength  = $ - szSym

szBSA	DB     'BC_SAB',0
	szBSALength = $ - szBSA

;	String descriptor for b_ULVars (shared data defined in UL).

sdULVars DW	szVarLength,OFFSET szVars ;string desc for b_ULVars

szVars	DB	'B_ULVARS',0		
	szVarLength = $ - szVars	

; Note:  The Name Buffer Length only needs to be a byte.  However by
; wasting one byte here, we save several bytes later in the file by
; not having to clear CH when we do a MOV CX,FNameBuffLen

	MaxFNameBuff = 13		; Maximum length of a filename

	DbPub	FNameBuff
	DbPub	FNameBuffLen
FNameBuff	DB  MaxFNameBuff DUP(?) ;Buffer for filename as it is created
FNameBuffLen	DW  1 DUP(0)		;Length of FNameBuff (must be inited)

;	The following three items are order-dependent.
	DbPub	SpecBuffer
InputMaxLen	DB	SpecBufLength	;max length for DOS 0AH input
InputStrLen	DB	1 DUP(?)	;length returned by DOS 0AH input
SpecBuffer	DB	FILNAML DUP(?)	;buffer for RTM file specification
	SpecBufLength	= FILNAML -1 -FilenameLength ;max path that will fit

;	Error messages are defined in the include file for localization.

INCLUDE	messages.inc

;***
;StartupStub - runtime module startup code (RTM Only).  Added with [41].
;
;Purpose:
;	This code is executed BEFORE the C startup.  The RTM is loaded
;	(if the program has not been chanined to), and the C startup (in
;	the RTM is jumped to).
;Entry:
;	DS = ES = PSP of new program.
;Exit:
;	RTM loaded if not chaining.
;Uses:
;	All.
;Exceptions:
;	None
;******************************************************************************


;***
; B$RtmLoad - runtime module loader (RTM Only)
;
;Purpose:
;	This code is executed BEFORE the C startup if the program has
;	not been chained.  The RTM is loaded and DGROUP is built.
;Entry:
;	SS = DGROUP of new program.
;	ES = LOADRTM
;Exit:
;	DS, ES destroyed.
;Uses:
;	All
;Exceptions:
;	Various errors given if error occurs in loading RTM.
;******************************************************************************


;***
; B$ULLoad - User library loader and initialization (UL Only)
;
;Purpose:
;	Added as part of revision [10].
;	This code is executed after the C startup.  QB4 has parsed the
;	command line and called B$IINIT to init the runtime.  B$IINIT
;	calls B$ULLOAD to load a user library.  B$ULLoad will determine
;	if a library is to be loaded, load it, and build DGROUP.
;Entry:
;	DS = DGROUP of new program.
;	SS:SI = ptr to command parameters
;		[SI]   - UlibNameOffset
;		[SI+2] - UlibNameSegment
;		[SI+4] - cbLibName
;	If [SI] = 0, then no /L was found
;	If [SI] = FFFF, then /L without filename found
;	else [SI+2]:[SI] = far pointer to filename, [SI+4] = length of filename
;
;Exit:
;	DS = ES = DGROUP of new program.
;	BP = 0
;	b$pULSyms = far pointer to symbol table for user library.
;
;Uses:
;	All.
;Exceptions:
;	Initialization errors:
;		"memory allocation" error
;		"disk I/O" error
;		"invalid format" error
;		"out of memory" error
;		"DOS memory arena corrupted" error
;******************************************************************************

;	Assume C startup has been done - program memory has been
;	cut back to top of STACK.

;	Code for user library loader.  Set up segment registers.


;*** 
; ULLoad - Core user library loader (UL Only)
;
;Purpose:
;	Added as part of revision [18].
;	Does the core user library loading.
;Entry:
;	DX:SI = Filename to load
;	CX    = Length of that file
;Exit:
;	AX - end of static data after load.
;Uses:
;	All.
;Exceptions:
;	Initialization errors:
;		"memory allocation" error
;		"disk I/O" error
;		"invalid format" error
;		"out of memory" error
;		"DOS memory arena corrupted" error
;******************************************************************************


;***
;	Standalone error messages - output and exit to DOS. (RTM and UL)
;
;******************************************************************************

NoFileError:			
	MOV	AX,ER_ULF	;get error number
	JMP	SHORT PrintError ;jump to give "cannot find file" error
MemAllocError:
	MOV	AX,ER_ULM	 ;get error number
	JMP	SHORT PrintError ;jump to give "memory allocation" error
OutOfMemError:
	MOV	AX,ER_ULO	 ;get error number
	JMP	SHORT PrintError ;jump to give "out of memory" error
ArenaBadError:
	MOV	AX,ER_DMA	 ;get error number
	JMP	SHORT PrintError ;jump to give "Arena trashed" error
InvalidError:
	MOV	AX,ER_ULI	 ;get error number
	JMP	SHORT PrintError ;jump to give "invalid userlib" error
DiskIOError:
	MOV	AX,ER_ULD	 ;get error number give "UL disk I/O" error

assumes DS,LOADRTM

PrintError:
	PUSH	SS		
	POP	DS		;set DS to current DGROUP

assumes DS,DGROUP


	PUSH	AX		;save error number
	MOV	AX,ER_ULE	;get number of UL error message preamble
	CALL	PrintMessage	;print message preamble
	CALL	PrintFileName	;print file name
	MOV	AX,ER_ULG	;get number of postamble
	CALL	PrintMessage	;print message postamble
	POP	AX		;recover error number
	CALL	PrintMessage	;Print error message
	CMP	b$ULSymSeg,0	;non zero if we have finished initialization
	JZ	Scram		;brif we haven't finished initialization
	JMP	B$END		;print error message and terminate

labelFP <PUBLIC,B$IScram>	;Kill QBI entry point

Scram:
	cmp	cs:fNoIntHooked,0	; do we have any interrupts hooked?
	jnz	NoIntHooked		; brif not
	push	ss			; DS = DGROUP