;******************** (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: | |
; 05/24/2006 : 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. | |
;******************************************************************************/ | |
; Depending in Your Application, Disable or Enable the following Define | |
; #define BUFFERED_Mode ; Work on Buffered mode, when enabling this define | |
; just enable the Buffered define on 91x_conf.h | |
; --- 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 | |
;--- BASE ADDRESSES | |
; System memory locations | |
SRAM_Base EQU 0x04000000 | |
SRAM_Limit EQU 0x04018000 ; at the top of 96 KB SRAM | |
SVC_Stack DEFINE SRAM_Limit ; 512 byte SVC stack at | |
; top of memory - used by kernel. | |
IRQ_Stack DEFINE SVC_Stack-512 ; followed by IRQ stack | |
USR_Stack DEFINE IRQ_Stack-512 ; followed by USR stack. Tasks run in | |
; system mode but task stacks are allocated | |
; when the task is created. | |
FIQ_Stack DEFINE USR_Stack-8 ; followed by FIQ stack | |
ABT_Stack DEFINE FIQ_Stack-8 ; followed by ABT stack | |
UND_Stack DEFINE ABT_Stack-8 ; followed by UNDEF stack | |
EXTERN main | |
; STR9X register specific definition | |
FMI_BBSR_AHB_UB EQU 0x54000000 | |
FMI_BBADR_AHB_UB EQU 0x5400000C | |
FMI_NBBSR_AHB_UB EQU 0x54000004 | |
FMI_NBBADR_AHB_UB EQU 0x54000010 | |
SCU_SCRO_APB1_UB EQU 0x4C002034 | |
SCRO_AHB_UNB EQU 0x5C002034 | |
;--------------------------------------------------------------- | |
; ?program_start | |
;--------------------------------------------------------------- | |
MODULE ?program_start | |
RSEG ICODE:CODE(2) | |
IMPORT LINK | |
PUBLIC __program_start | |
EXTERN ?main | |
CODE32 | |
__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 | |
ldr r0,=LINK ; to include the vector table inside the final executable. | |
; --- 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, =0x54000000 | |
LDR R7, =0x4 | |
STR R7, [R6] | |
LDR R6, =0x54000004 | |
LDR R7, =0x3 | |
STR R7, [R6] | |
LDR R6, =0x5400000C | |
LDR R7, =0x0 | |
STR R7, [R6] | |
LDR R6, =0x54000010 | |
LDR R7, =0x20000 | |
STR R7, [R6] | |
LDR R6, =0x54000018 | |
LDR R7, =0x18 | |
STR R7, [R6] | |
; --- Enable 96K RAM | |
LDR R0, = SCRO_AHB_UNB | |
LDR R1, = 0x0196 | |
STR R1, [R0] | |
/* Setup a stack for each mode - note that this only sets up a usable stack | |
for system/user, SWI and IRQ modes. Also each mode is setup with | |
interrupts initially disabled. */ | |
MSR CPSR_c, #Mode_FIQ|I_Bit|F_Bit ; No interrupts | |
LDR SP, =FIQ_Stack | |
MSR CPSR_c, #Mode_IRQ|I_Bit|F_Bit ; No interrupts | |
LDR SP, =IRQ_Stack | |
MSR CPSR_c, #Mode_ABT|I_Bit|F_Bit ; No interrupts | |
LDR SP, =ABT_Stack | |
MSR CPSR_c, #Mode_UND|I_Bit|F_Bit ; No interrupts | |
LDR SP, =UND_Stack | |
MSR CPSR_c, #Mode_SVC|I_Bit|F_Bit ; No interrupts | |
LDR SP, =SVC_Stack | |
MSR CPSR_c, #Mode_SYS|I_Bit|F_Bit ; No interrupts | |
LDR SP, =USR_Stack | |
/* We want to start in supervisor mode. Operation will switch to system | |
mode when the first task starts. */ | |
MSR CPSR_c, #Mode_SVC|I_Bit|F_Bit | |
; --- Set bits 17-18 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**** | |