EXEHEX - A Microsoft EXE to Intel HEX file converter

This program converts Microsoft .EXE files to Intel HEX files 

suitable for burning into EPROM. Like the loader in MSDOS, 

exehex performs any necessary relocation of segments in the 

.EXE file.

				EXEHEX



This program is used to convert Microsoft .EXE files to Intel HEX files that  are suitable for burning into EPROM.



You CANNOT simply take your favorite program such as Microsoft WORD, and expect

the exehex program make it work in EPROM.  You must write the programs to be

used with this utility carefully, and with the full intent of running them on

an embedded 80x86 microprocessor system.



Some things that must be done to be successful:



1) Write a simple jump vector program in MASM that will reside in EPROM at

   address FFFF:0000.  This program should consist of something like this for

   an 8086/8088:



PwrInit	segment para public 'Code'

	Public	Power_Start

Power_Start	proc	far

	org	0

;	jmp	far ptr 0F000:0000H		;MASM won't allow this, so...

	db	0EAH				;fake a far jump to EPROM start

	dd	0F0000000H			;(segment)(offset)



Power_Start	endp

PwrInit	ends

	end





   Then after linking with Microsoft linker, you pass the file thru

   exehex like this:



	exehex -SFFFF -O0000 powerini.exe powerini.hex



   This startup vector is setup to reside at FFFF:0000 in EPROM, and to jump

   to the first location in EPROM where your program will begin.



2) Write a short chunk of code that will reside at the first location in your

   EPROM (in this case F000:0000).  This code will setup the segment registers,

   stack, interrupt vectors, copy initialized data to ram, and then when done,

   will branch to your application program.



EPROMST	segment para public 'Code'

	Public	EPROM_Begin

EPROM_Begin	proc	near

	org	0

	xor	ax,ax			;this example assumes 64K of RAM

	mov	ds,ax

	mov	es,ax

	mov	ss,ax

	mov	sp,STACK_TOP



	xor	si,si			;int vectors start at offset 0

	mov	cx,256			;number of possible interrupt vectors



	mov	ax,0000H		;set all vectors to power restart

	mov	dx,0FFFFH		;they should really go to default handler.

IV_Loop:

	mov	[si],ax

	add	si,2

	mov	[si],dx

	add	si,2

	loop	IV_Loop

	.

	.

	jmp	Your_Code_Begin



EPROM_Begin	endp

EPROMST	ends

	end



   Then link your code, and pass it thru exehex like this:



	exehex -SF000 -O0000 -N yourcode.exe yourcode.hex



3) Cat your power start vector to your linked code:



	copy yourcode.hex + powerini.hex EPROM.HEX



4) Burn EPROM.HEX using your favorite method of burning intel hex files, and

   watch your project come to life.



5) Be sure to include a file that defines the segment ordering with every

   assembly language file in the program.  For example:



	.seg				;say you want segments in order shown

EPROMST	segment para public 'Code'

EPROMST ends



Code	segment para public 'Code'

Code	ends



PwrInit	segment para public 'Code'

PwrInit	ends



6) Be sure and present the Code segment files to the the linker in the same

   order that you want them to appear in EPROM. (eg. it would be handy to

   have your startup code appear first in the EPROM. ;-) )



7) Initialized data segments must not appear in the assembled output.  If you

   want to initialize data, you must put that data into the EPROM in the code

   segment.  If you want to be able to change the value of the initialized

   data, you must make your program copy the data into the proper location in

   RAM, and use it there (eg, the data must have the same offset it had in

   EPROM, but just be in the RAM segment).



I have examples of startup code for 80186/80188 processors too, If you really

need them, something can be arranged.  Bear in mind that I do this embedded

processor stuff as my sole means of support and livelyhood, not just for fun.



Good Luck, If you have any questions, comments, or bug reports, I can be

reached by email at: chuck@eng.umd.edu or:





		Chuck Harris



		C.F. Harris - Consulting

		9308 Canterbury Riding

		Laurel, Maryland 20723

		(301)490-7443