interrupt.c(36): error: #18: expected a ")"

Are you using Arm Compiler 5 (armcc) or Arm Compiler 6 (armclang)? The inline assembly formats are quite different, armclang generally supports the gcc format.

For armcc, see:
https://developer.arm.com/documentation/dui0472/m/Using-the-Inline-and-Embedded-Assemblers-of-the-ARM-Compiler

For armclang, see:
https://developer.arm.com/documentation/100748/0620/Using-Assembly-and-Intrinsics-in-C-or-C---Code/Writing-inline-assembly-code

Regards, Ronan

Are you using Arm Compiler 5 (armcc) or Arm Compiler 6 (armclang)? The inline assembly formats are quite different, armclang generally supports the gcc format.

For armcc, see:
https://developer.arm.com/documentation/dui0472/m/Using-the-Inline-and-Embedded-Assemblers-of-the-ARM-Compiler

For armclang, see:
https://developer.arm.com/documentation/100748/0620/Using-Assembly-and-Intrinsics-in-C-or-C---Code/Writing-inline-assembly-code

Regards, Ronan

This is for an LPC2388 so I must (I think) be using armcc.    I wasn't aware of that distinction as I am new to coding for ARM and the Keil tooling.

I can (at a later date) read the manuals in some detail, but right now if you could let me know how to "fix that" I'd be grateful.

Thanks, David

I looked at the referenced docs and am no further forward.  Please will someone provide me with the correct syntax or a link to a page that will show me.

Thanks, David

Hello David,

It is difficult to answer this without the full context - inline assembler code depends on the C code around it.

The following builds for me with armcc:

int foo(){
	int r0, r1, r2;
	
	__asm{
		MOV r0, 0
		MOV r1, 1
		MOV r2, 2
		SWI 3
	}
	
	return (r0+r1+r2);
}

Yes I understand:

/* Register an ISR */
void RegisterIrq (
	int irq,
	void(*isr)(void),
	int pri
)
{
	asm (
	"@ MOV R0, %0\n"
	"@ MOV R1, %1\n"
	"@ MOV R2, %2\n"
	"swi 3\n" : : "r" (irq), "r" (isr), "r" (pri)	
	);
}

I don't believe it's adding r0-R2  they get passed into the SWI invocation:

		EXPORT SWI_Handler
		PRESERVE8
SWI_Handler
		MRS		IP, SPSR
		TST		IP, #B_Thumb	; Check caller's state, ARM or Thumb
		LDRNEH	IP, [LR, #-2]	; Get swi instruction code (in Thumb state)
		LDREQ	IP, [LR, #-4]	; Get swi instruction code (in ARM state)
		AND		IP, #0xFF		; Get swi comment field (lower 8 bit)
		CMP		IP, #7			; Check range
		LDRLO	PC, [PC, IP, LSL #2]	; Jump to each service function when code is valid
		MOVS	PC, LR			; Otherwise return
		DCD		irq_disable	; 0 Disable IRQ
		DCD		irq_enable	; 1 Enable IRQ
		DCD		clear_vect	; 2 Clear ISRs
		DCD		reg_irq		; 3 Register vector address for IRQ
		DCD		sel_fiq		; 4 Select FIQ interrupt
		DCD		load_fiq	; 5 Load FIQ shadow regs from memory
		DCD		store_fiq	; 6 Store FIQ shadow regs to memory

;
; Omitted
;

reg_irq					; Register an IRQ
		CMP		R0, #32				; Range check
		MOVCSS	PC, LR
		LDR		IP, =(LPC_BASE_VIC+VIC_VectAddr0)
		STR		R1, [IP, R0, LSL #2]	; Set VICVectVectAddr<n>
		LDR		IP, =(LPC_BASE_VIC+VIC_VectPriority0)
		STR		R2, [IP, R0, LSL #2]	; Set VICVectPriority<n>
		MOV		R1, #1
		MOV		R1, R1, LSL R0
		LDR		IP, =LPC_BASE_VIC
		LDR		R2, [IP, #VIC_IntSelect]	; Clear corresponding bit in the VICIntSelect
		BIC		R2, R1
		STR		R2, [IP, #VIC_IntSelect]
		STR		R1, [IP, #VIC_IntEnable]	; Enable corresponding interrupt
		MOVS	PC, LR

;
; omitted
;

/* Register an ISR */
void RegisterIrq (
	int irq,
	void(*isr)(void),
	int pri
)
	
	__asm{
       SWI 3
	}
}

This is what was generated:

    31: { 
    32: //      asm ( 
    33: //      "@ MOV R0, %0\n" 
    34: //      "@ MOV R1, %1\n" 
    35: //      "@ MOV R2, %2\n" 
    36: //      "swi 3\n" : : "r" (irq), "r" (isr), "r" (pri)  
    37: //      ); 
    38:         __asm{ 
0x00002CD4  E92D4070  STMDB     R13!,{R4-R6,R14}
0x00002CD8  E1A04000  MOV       R4,R0
0x00002CDC  E1A05001  MOV       R5,R1
0x00002CE0  E1A06002  MOV       R6,R2
    39:        SWI 3 
    40:         } 
0x00002CE4  EF000003  SWI       0x00000003
    41: } 
0x00002CE8  E8BD4070  LDMIA     R13!,{R4-R6,R14}
0x00002CEC  E12FFF1E  BX        R14

I deleted interrupt.c and changed interrupt.h to read:

__swi(0) void IrqDisable (void);	/* Disable all IRQ */
__swi(1) void IrqEnable (void); 	/* Enable all IRQ */
__swi(2) void ClearVector (void);	/* Unregister all ISRs */
__swi(3) void RegisterIrq (int irq, void(*isr)(void), int pri);	/* Register an ISR as IRQ */
__swi(4) void SelectFiq (int irq);	/* Switch an interrtupt source as FIQ */
__swi(5) void LoadFiqRegs (long *regs);	/* Load shadow regs R8-R12 from memory */
__swi(6) void StoreFiqRegs (long *regs); /* Store shadow regs R8-R12 to memory */

That seems to have a) resolved any issues with asm format and b) simplified the code!!

I added those values so that they would not be optimized away. Inline assembler behaves quite different to the 'real' assembler.