53 lines
		
	
	
	
		
			802 B
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			53 lines
		
	
	
	
		
			802 B
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| #
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| ! $Source: /cvsroot/tack/Ack/plat/linux386/libsys/_syscall.s,v $
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| ! $State: Exp $
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| ! $Revision: 1.1 $
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| 
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| ! Declare segments (the order is important).
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| 
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| .sect .text
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| .sect .rom
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| .sect .data
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| .sect .bss
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| 
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| .sect .text
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| 
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| EINVAL = 22
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| 
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| #define IFFALSE 4
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| #define IFTRUE 12
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| #define ALWAYS 20
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| 
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| #define LT 0
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| #define GT 1
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| #define EQ 2
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| #define OV 3
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| 	
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| ! Perform a Linux system call.
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| 
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| .define __syscall
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| __syscall:
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| 	lwz r0, 0(sp)
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| 	lwz r3, 4(sp)
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| 	lwz r4, 8(sp)
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| 	lwz r5, 12(sp)
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| 	sc 0
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| 	bclr IFFALSE, OV, 0
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| 	
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| 	! On error, r3 contains the errno.	
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| 	! It just so happens that errnos 1-34 are the same in Linux as in ACK.
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| 	cmpi cr0, 0, r3, 1
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| 	bc IFTRUE, LT, 2f
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| 	cmpi cr0, 0, r3, 34
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| 	bc IFTRUE, GT, 2f
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| 	
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| 3:
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| 	addis r4, r0, <_errno
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| 	ori r4, r4, >_errno
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| 	stw r3, 0(r4)
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| 	addi r3, r0, -1
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| 	bclr ALWAYS, 0, 0
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| 	
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| 2:
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| 	addi r3, r0, EINVAL
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| 	b 3b
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