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;----------------------------------------------------------------------------- 
; This file contains the startup code used by the ICCARM C compiler. 
; 
; The modules in this file are included in the libraries, and may be replaced 
; by any user-defined modules that define the PUBLIC symbol _program_start or 
; a user defined start symbol. 
; To override the cstartup defined in the library, simply add your modified 
; version to the workbench project. 
; 
; All code in the modules (except ?RESET) will be placed in the ICODE segment. 
; 
; $Revision: 1.53 $ 
; 
;----------------------------------------------------------------------------- 
	 
; 
; Naming covention of labels in this file: 
; 
;  ?xxx	  - External labels only accessed from assembler. 
;  __xxx  - External labels accessed from or defined in C. 
;  xxx	  - Labels local to one module (note: this file contains  
;           several modules). 
;  main	  - The starting point of the user program. 
; 
 
;--------------------------------------------------------------- 
; Macros and definitions for the whole file 
;--------------------------------------------------------------- 
 
; Mode, correspords to bits 0-5 in CPSR 
MODE_BITS	DEFINE	0x1F		; Bit mask for mode bits in CPSR 
USR_MODE	DEFINE	0x10		; User mode 
FIQ_MODE	DEFINE	0x11		; Fast Interrupt Request mode 
IRQ_MODE	DEFINE	0x12		; Interrupt Request mode 
SVC_MODE	DEFINE	0x13		; Supervisor mode 
ABT_MODE	DEFINE	0x17		; Abort mode 
UND_MODE	DEFINE	0x1B		; Undefined Instruction mode 
SYS_MODE	DEFINE	0x1F		; System mode 
	 
 
;--------------------------------------------------------------- 
; ?RESET 
; Reset Vector. 
; Normally, segment INTVEC is linked at address 0. 
; For debugging purposes, INTVEC may be placed at other 
; addresses. 
; A debugger that honors the entry point will start the 
; program in a normal way even if INTVEC is not at address 0. 
;--------------------------------------------------------------- 
 
		MODULE	?RESET 
		COMMON	INTVEC:CODE:NOROOT(2) 
		PUBLIC  __program_start 
		EXTERN	?cstartup 
		EXTERN	undef_handler, swi_handler, prefetch_handler 
		EXTERN	data_handler, irq_handler, fiq_handler 
		CODE32	; Always ARM mode after reset	 
		org	0x00 
__program_start 
		ldr	pc,=?cstartup  ; Absolute jump can reach 4 GByte 
;		b	?cstartup    ; Relative branch allows remap, limited to 32 MByte 
		org	0x04 
;		ldr	pc,=undef_handler 
		org	0x08 
;		ldr	pc,=swi_handler 
		org	0x0c 
;		ldr	pc,=prefetch_handler 
		org	0x10 
;		ldr	pc,=data_handler 
		org	0x18 
;		ldr	pc,=irq_handler 
		org	0x1c 
;		ldr	pc,=fiq_handler 
 
		; Constant table entries (for ldr pc) will be placed at 0x20 
		org	0x20 
		LTORG 
;		ENDMOD	__program_start 
                ENDMOD 
 
 
;--------------------------------------------------------------- 
; ?CSTARTUP 
;--------------------------------------------------------------- 
		MODULE	?CSTARTUP 
 
		RSEG	IRQ_STACK:DATA(2) 
		RSEG	SVC_STACK:DATA:NOROOT(2) 
		RSEG	CSTACK:DATA(2) 
		RSEG	ICODE:CODE:NOROOT(2) 
		PUBLIC	?cstartup 
		EXTERN	?main 
 
; Execution starts here. 
; After a reset, the mode is ARM, Supervisor, interrupts disabled. 
 
 
		CODE32 
?cstartup 
 
; Add initialization nedded before setup of stackpointers here 
 
 
; Initialize the stack pointers. 
; The pattern below can be used for any of the exception stacks: 
; FIQ, IRQ, SVC, ABT, UND, SYS. 
; The USR mode uses the same stack as SYS.  
; The stack segments must be defined in the linker command file, 
; and be declared above. 
                mrs     r0,cpsr                             ; Original PSR value 
                bic     r0,r0,#MODE_BITS                    ; Clear the mode bits 
                orr     r0,r0,#IRQ_MODE                     ; Set IRQ mode bits 
                msr     cpsr_c,r0                           ; Change the mode 
                ldr     sp,=SFE(IRQ_STACK) & 0xFFFFFFF8     ; End of IRQ_STACK 
                 
                bic     r0,r0,#MODE_BITS                    ; Clear the mode bits 
                orr     r0,r0,#SYS_MODE                     ; Set System mode bits 
                msr     cpsr_c,r0                           ; Change the mode 
                ldr     sp,=SFE(CSTACK) & 0xFFFFFFF8        ; End of CSTACK 
 
#ifdef __ARMVFP__ 
; Enable the VFP coprocessor. 
                mov     r0, #0x40000000                 ; Set EN bit in VFP 
                fmxr    fpexc, r0                       ; FPEXC, clear others. 
 
; Disable underflow exceptions by setting flush to zero mode. 
; For full IEEE 754 underflow compliance this code should be removed 
; and the appropriate exception handler installed. 
                mov     r0, #0x01000000		        ; Set FZ bit in VFP 
                fmxr    fpscr, r0                       ; FPSCR, clear others. 
#endif 
         
; Add more initialization here 
 
 
; Continue to ?main for more IAR specific system startup 
 
                ldr     r0,=?main         
                bx      r0         
             
                LTORG 
                             
                ENDMOD 
             
             
                END