68 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			ArmAsm
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			68 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			ArmAsm
		
	
	
		
			Executable File
		
	
	
	
	
! This is the Modula-2 run-time start-off routine.  It's job is to take the
 | 
						|
! arguments as put on the stack by EXEC, and to parse them and set them up the
 | 
						|
! way _m_a_i_n expects them.
 | 
						|
 | 
						|
.sect .text; .sect .rom; .sect .data; .sect .bss
 | 
						|
 | 
						|
.define begtext, begdata, begbss
 | 
						|
.sect .text
 | 
						|
begtext:
 | 
						|
.sect .rom
 | 
						|
begrom:
 | 
						|
.sect .data
 | 
						|
begdata:
 | 
						|
.sect .bss
 | 
						|
begbss:
 | 
						|
 | 
						|
.define m2rtso, hol0, __penviron, __penvp, __fpu_present
 | 
						|
.sect .text
 | 
						|
m2rtso:
 | 
						|
	xor	ebp, ebp		! clear for backtrace of core files
 | 
						|
	mov	eax, (esp)		! argc
 | 
						|
	lea	edx, 4(esp)		! argv
 | 
						|
	lea	ecx, 8(esp)(eax*4)	! envp
 | 
						|
 | 
						|
	! Test if environ is in the initialized data area and is set to our
 | 
						|
	! magic number.  If so then it is not redefined by the user.
 | 
						|
	mov	ebx, _environ
 | 
						|
	cmp	ebx, __edata		! within initialized data?
 | 
						|
	jae	0f
 | 
						|
	testb	bl, 3			! aligned?
 | 
						|
	jnz	0f
 | 
						|
	cmp	(ebx), 0x53535353	! is it our environ?
 | 
						|
	jne	0f
 | 
						|
	mov	(__penviron), ebx	! _penviron = &environ;
 | 
						|
0:	mov	ebx, (__penviron)
 | 
						|
	mov	(ebx), ecx		! *_penviron = envp;
 | 
						|
 | 
						|
	push	ecx			! push envp
 | 
						|
	push	edx			! push argv
 | 
						|
	push	eax			! push argc
 | 
						|
 | 
						|
	! Test the EM bit of the MSW to determine if an FPU is present and
 | 
						|
	! set __fpu_present if one is found.
 | 
						|
	smsw	ax
 | 
						|
	testb	al, 0x4			! EM bit in MSW
 | 
						|
	setz	(__fpu_present)		! True if not set
 | 
						|
 | 
						|
	call	__m_a_i_n		! run Modula-2 program
 | 
						|
 | 
						|
	push	eax			! push exit status
 | 
						|
	call	__exit
 | 
						|
 | 
						|
	hlt				! force a trap if exit fails
 | 
						|
 | 
						|
.sect .rom
 | 
						|
	.data4	0			! Separate I&D: *NULL == 0
 | 
						|
					! Also keeps the first string in the
 | 
						|
					! program from appearing at location 0!
 | 
						|
.sect .data
 | 
						|
__penviron:
 | 
						|
	.data4	__penvp			! Pointer to environ, or hidden pointer
 | 
						|
 | 
						|
.sect .bss
 | 
						|
	.comm	__penvp, 4		! Hidden environment vector
 | 
						|
	.comm	__fpu_present, 4	! FPU present flag
 | 
						|
 | 
						|
.extern endtext				! Force loading of end labels.
 |