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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; Part one of the system initialization code,
;; contains low-level
;; initialization.
;;
;; Copyright 2006 IAR Systems. All rights reserved.
;;
;; $Revision: 10608 $
;;
MODULE ?cstartup
;; Forward declaration of sections.
SECTION IRQ_STACK:DATA:NOROOT(3)
SECTION ABT_STACK:DATA:NOROOT(3)
SECTION SVC_STACK:DATA:NOROOT(3)
SECTION UND_STACK:DATA:NOROOT(3)
SECTION FIQ_STACK:DATA:NOROOT(3)
SECTION CSTACK:DATA:NOROOT(3)
;
; The module in this file are included in the libraries, and may be
; replaced by any user-defined modules that define the PUBLIC symbol
; __iar_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.
SECTION .intvec:CODE:NOROOT(2)
PUBLIC __vector
PUBLIC __vector_0x14
PUBLIC __iar_program_start
EXTERN vPortYieldProcessor
ARM
__vector:
;;
ldr pc,[pc,#+24] ;; Reset
ldr pc,[pc,#+24] ;; Undefined instructions
;; ldr pc,[pc,#+24] ;; Software interrupt (SWI/SVC)
b vPortYieldProcessor
ldr pc,[pc,#+24] ;; Prefetch abort
ldr pc,[pc,#+24] ;; Data abort
__vector_0x14
DC32 0 ;; RESERVED
ldr pc, [PC, #-0xFF0] ;; IRQ
ldr pc,[pc,#+24] ;; FIQ
DC32 __iar_program_start ;; Reset
DC32 undef_handler ;; Undefined instructions
DC32 0 ;; Software interrupt (SWI/SVC)
DC32 prefetch_handler ;; Prefetch abort
DC32 data_handler ;; Data abort
DC32 0 ;; RESERVED
DC32 0 ;; IRQ
DC32 fiq_handler ;; FIQ
undef_handler
b undef_handler
prefetch_handler
b prefetch_handler
data_handler
b data_handler
fiq_handler
b fiq_handler
; --------------------------------------------------
; ?cstartup -- low-level system initialization code.
;
; After a reser execution starts here, the mode is ARM, supervisor
; with interrupts disabled.
;
SECTION .text:CODE:NOROOT(2)
; PUBLIC ?cstartup
EXTERN ?main
REQUIRE __vector
ARM
__iar_program_start:
?cstartup:
;
; Add initialization needed before setup of stackpointers here.
;
; Errata MAM.1Incorrect read of data from SRAM after Reset and MAM
; is not enabled or partially enabled.
; Work-around: User code should enable the MAM after Reset and before
; any RAM accesses
MAMCR DEFINE 0xE01FC000 ; MAM Control Register
MAMTIM DEFINE 0xE01FC004 ; MAM Timing register
ldr r0,=MAMCR
ldr r1,=MAMTIM
ldr r2,=0
str r2,[r0]
ldr r2,=3 ; 1 < 20 MHz; 20 MHz < 2 < 40 MHz; 40MHz > 3
str r2,[r1]
ldr r2,=2
str r2,[r0]
; 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.
;
; --------------------
; 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
MRS r0, cpsr ; Original PSR value
BIC r0, r0, #MODE_BITS ; Clear the mode bits
ORR r0, r0, #ABT_MODE ; Set ABT mode bits
MSR cpsr_c, r0 ; Change the mode
LDR sp, =SFE(ABT_STACK) ; End of ABT_STACK
BIC r0, r0, #MODE_BITS ; Clear the mode bits
ORR r0, r0, #SVC_MODE ; Set SVC mode bits
MSR cpsr_c, r0 ; Change the mode
LDR sp, =SFE(SVC_STACK) ; End of SVC_STACK
BIC r0, r0, #MODE_BITS ; Clear the mode bits
ORR r0, r0, #UND_MODE ; Set UND mode bits
MSR cpsr_c, r0 ; Change the mode
LDR sp, =SFE(UND_STACK) ; End of UND_STACK
BIC r0, r0, #MODE_BITS ; Clear the mode bits
ORR r0, r0, #FIQ_MODE ; Set FIQ mode bits
MSR cpsr_c, r0 ; Change the mode
LDR sp, =SFE(FIQ_STACK) ; End of FIQ_STACK
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) ; 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) ; 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
;
BIC r0, r0, #MODE_BITS ; Clear the mode bits
ORR r0, r0, #SVC_MODE ; Set SVC mode bits
MSR cpsr_c, r0 ; Change the mode
; Continue to ?main for C-level initialization.
LDR r0, =?main
BX r0
END