| ;******************** (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**** | |