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;******************** (C) COPYRIGHT 2006 STMicroelectronics ********************
;* File Name : 91x_init.s
;* Author : MCD Application Team
;* Date First Issued : 05/18/2006 : Version 1.0
;* Description : This module performs:
;* - FLASH/RAM initialization,
;* - Stack pointer initialization for each mode ,
;* - Branches to ?main in the C library (which eventually
;* calls main()).
;*
;* On reset, the ARM core starts up in Supervisor (SVC) mode,
;* in ARM state,with IRQ and FIQ disabled.
;*******************************************************************************
;* History:
;* 05/22/2007 : Version 1.2
;* 05/24/2006 : Version 1.1
;* 05/18/2006 : Version 1.0
;*******************************************************************************
;* THE PRESENT SOFTWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS WITH
;* CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME. AS
;* A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT, INDIRECT
;* OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE CONTENT
;* OF SUCH SOFTWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING INFORMATION
;* CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
;******************************************************************************/
; At power up, the CPU defaults to run on the oscillator clock, so Depending
; of your Application, Disable or Enable the following Define
#define PLL_Clock ; Use PLL as the default clock source @ 96 MHz only with
; Bank 0 @ 0x0 and Bank 1 @ 0x80000
; #define RTC_Clock ; Use RTC as the default clock source
; #define OSC_Clock ; Use OSC as the default clock source
; --- Standard definitions of mode bits and interrupt (I & F) flags in PSRs
Mode_USR EQU 0x10
Mode_FIQ EQU 0x11
Mode_IRQ EQU 0x12
Mode_SVC EQU 0x13
Mode_ABT EQU 0x17
Mode_UND EQU 0x1B
Mode_SYS EQU 0x1F ; available on ARM Arch 4 and later
I_Bit EQU 0x80 ; when I bit is set, IRQ is disabled
F_Bit EQU 0x40 ; when F bit is set, FIQ is disabled
; --- STR9X SCU specific definitions
SCU_BASE_Address EQU 0x5C002000 ; SCU Base Address
SCU_CLKCNTR_OFST EQU 0x00000000 ; Clock Control register Offset
SCU_PLLCONF_OFST EQU 0x00000004 ; PLL Configuration register Offset
SCU_SYSSTATUS_OFST EQU 0x00000008 ; System Status Register Offset
SCU_SCR0_OFST EQU 0x00000034 ; System Configuration Register 0 Offset
; --- STR9X FMI specific definitions
FMI_BASE_Address EQU 0x54000000 ; FMI Base Address
FMI_BBSR_OFST EQU 0x00000000 ; Boot Bank Size Register
FMI_NBBSR_OFST EQU 0x00000004 ; Non-boot Bank Size Register
FMI_BBADR_OFST EQU 0x0000000C ; Boot Bank Base Address Register
FMI_NBBADR_OFST EQU 0x00000010 ; Non-boot Bank Base Address Register
FMI_CR_OFST EQU 0x00000018 ; Control Register
;---------------------------------------------------------------
; ?program_start
;---------------------------------------------------------------
MODULE ?program_start
SECTION IRQ_STACK:DATA:NOROOT(3)
SECTION FIQ_STACK:DATA:NOROOT(3)
SECTION UND_STACK:DATA:NOROOT(3)
SECTION ABT_STACK:DATA:NOROOT(3)
SECTION SVC_STACK:DATA:NOROOT(3)
SECTION CSTACK:DATA:NOROOT(3)
SECTION .icode:CODE:NOROOT(2)
PUBLIC __iar_program_start
EXTERN ?main
CODE32
__iar_program_start:
LDR pc, =NextInst
NextInst
NOP ; execute some instructions to access CPU registers after wake
NOP ; up from Reset, while waiting for OSC stabilization
NOP
NOP
NOP
NOP
NOP
NOP
NOP
; BUFFERED_Mode
; ------------------------------------------------------------------------------
; Description : Enable the Buffered mode.
; Just enable the buffered define on the 91x_conf.h
; http://www.arm.com/pdfs/DDI0164A_966E_S.pdf
; ------------------------------------------------------------------------------
MRC p15, 0, r0, c1, c0, 0 ; Read CP15 register 1 into r0
ORR r0, r0, #0x8 ; Enable Write Buffer on AHB
MCR p15, 0, r0, c1, c0, 0 ; Write CP15 register 1
; --- Remap Flash Bank 0 at address 0x0 and Bank 1 at address 0x80000,
; when the bank 0 is the boot bank, then enable the Bank 1.
LDR R6, =FMI_BASE_Address
LDR R7, = 0x4 ; BOOT BANK Size = 512KB
STR R7, [R6, #FMI_BBSR_OFST] ; (2^4) * 32 = 512KB
LDR R7, = 0x2 ; NON BOOT BANK Size = 32KB
STR R7, [R6, #FMI_NBBSR_OFST] ; (2^2) * 8 = 32KB
LDR R7, = 0x0 ; BOOT BANK Address = 0x0
STR R7, [R6, #FMI_BBADR_OFST]
LDR R7, = 0x20000 ; NON BOOT BANK Address = 0x80000
STR R7, [R6, #FMI_NBBADR_OFST] ; need to put 0x20000 because FMI
; bus on A[25:2] of CPU bus
LDR R7, = 0x18 ; Enable CS on both banks
STR R7, [R6, #FMI_CR_OFST] ; LDR R7, = 0x19 ;in RevD
; to enable 8 words PFQ deepth
; --- Enable 96K RAM, PFQBC enabled, DTCM & AHB wait-states disabled
LDR R0, = SCU_BASE_Address
LDR R1, = 0x0191
STR R1, [R0, #SCU_SCR0_OFST]
; ------------------------------------------------------------------------------
; --- System clock configuration
; ------------------------------------------------------------------------------
#ifdef PLL_Clock ; Use 96 MHZ PLL clock as the default frequency
; --- wait states Flash confguration
LDR R6, = 0x00080000 ;Write a Write Flash Configuration
LDR R7, =0x60 ;Register command (60h) to any word
STRH R7, [R6] ;address in Bank 1.
LDR R6, = 0x00083040 ;Write a Write Flash Configuration
LDR R7, = 0x3 ;Register Confirm command (03h)
STRH R7, [R6] ;2Wstaites in read,PWD,LVD enabled,
;High BUSCFG.
; --- PLL configuration
LDR R1, = 0x00020002 ;Set OSC as clock source
STR R1, [R0, #SCU_CLKCNTR_OFST ]
NOP ; Wait for OSC stabilization
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
LDR R1, = 0x000ac019 ;Set PLL ENABLE, to 96Mhz
STR R1, [R0, #SCU_PLLCONF_OFST]
Wait_Loop
LDR R1,[R0, #SCU_SYSSTATUS_OFST] ;Wait until PLL is Locked
ANDS R1, R1, #0x01
BEQ Wait_Loop
LDR R1, = 0x00020080 ;Set PLL as clock source after pll
STR R1, [R0, #SCU_CLKCNTR_OFST ] ;is locked and FMICLK=RCLK,
;PCLK=RCLK/2
#endif
#ifdef RTC_Clock ;Use RTC as the default clock source
LDR R1, = 0x00020001 ;Set RTC as clock source and
STR R1, [R0, #SCU_CLKCNTR_OFST ] ;FMICLK=RCLK, PCLK=RCLK
#endif
#ifdef OSC_Clock ;Use Osc as the default clock source
LDR R1, = 0x00020002 ;Set OSC as clock source and
STR R1, [R0, #SCU_CLKCNTR_OFST ] ;FMICLK=RCLK, PCLK=RCLK
#endif
; --- Initialize Stack pointer registers
; Enter each mode in turn and set up the stack pointer
MSR CPSR_c, #Mode_FIQ|I_Bit|F_Bit ; No interrupts
LDR SP, =SFE(FIQ_STACK)
MSR CPSR_c, #Mode_IRQ|I_Bit|F_Bit ; No interrupts
LDR SP, = SFE(IRQ_STACK)
MSR CPSR_c, #Mode_ABT|I_Bit|F_Bit ; No interrupts
LDR SP, = SFE(ABT_STACK)
MSR CPSR_c, #Mode_UND|I_Bit|F_Bit ; No interrupts
LDR SP, = SFE(UND_STACK)
MSR CPSR_c, #Mode_SYS ; IRQs & FIQs are now enabled
LDR SP, = SFE(CSTACK)
MSR CPSR_c, #Mode_SVC|I_Bit|F_Bit ; No interrupts
LDR SP, = SFE(SVC_STACK)
; --- Set bits 17-18(DTCM/ITCM order bits)of the Core Configuration Control
; Register
MOV r0, #0x60000
MCR p15,0x1,r0,c15,c1,0
; --- Now enter the C code
B ?main ; Note : use B not BL, because an application will
; never return this way
LTORG
END
;******************* (C) COPYRIGHT 2006 STMicroelectronics *****END OF FILE****