;******************** (C) COPYRIGHT 2006 STMicroelectronics ******************** ;* File Name : 75x_init.s ;* Author : MCD Application Team ;* Date First Issued : 03/10/2006 ;* Description : This module performs: ;* - Memory remapping (if required), ;* - Stack pointer initialisation for each mode , ;* - Interrupt Controller Initialisation ;* - 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: ; 07/17/2006 : V1.0 ; 03/10/2006 : V0.1 ;******************************************************************************* ; 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. ;******************************************************************************* IMPORT WAKUP_Addr ; imported from 75x_vect.s ; Depending on Your Application, Disable or Enable the following Defines ; ---------------------------------------------------------------------------- ; SMI Bank0 configuration ; ---------------------------------------------------------------------------- ; If you need to accees the SMI Bank0 ; uncomment next line ;#define SMI_Bank0_EN ; ---------------------------------------------------------------------------- ; Memory remapping ; ---------------------------------------------------------------------------- ;#define Remap_SRAM ; remap SRAM at address 0x00 ; ---------------------------------------------------------------------------- ; EIC initialization ; ---------------------------------------------------------------------------- #define EIC_INIT ; Configure and Initialize EIC ; 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 I_Bit EQU 0x80 ; when I bit is set, IRQ is disabled F_Bit EQU 0x40 ; when F bit is set, FIQ is disabled ; MRCC Register MRCC_PCLKEN_Addr EQU 0x60000030 ; Peripheral Clock Enable register base address ; CFG Register CFG_GLCONF_Addr EQU 0x60000010 ; Global Configuration register base address SRAM_mask EQU 0x0002 ; to remap RAM at 0x0 ; GPIO Register GPIOREMAP0R_Addr EQU 0xFFFFE420 SMI_EN_Mask EQU 0x00000001 ; SMI Register SMI_CR1_Addr EQU 0x90000000 ; EIC Registers offsets EIC_Base_addr EQU 0xFFFFF800 ; EIC base address ICR_off_addr EQU 0x00 ; Interrupt Control register offset CIPR_off_addr EQU 0x08 ; Current Interrupt Priority Register offset IVR_off_addr EQU 0x18 ; Interrupt Vector Register offset FIR_off_addr EQU 0x1C ; Fast Interrupt Register offset IER_off_addr EQU 0x20 ; Interrupt Enable Register offset IPR_off_addr EQU 0x40 ; Interrupt Pending Bit Register offset SIR0_off_addr EQU 0x60 ; Source Interrupt Register 0 ;--------------------------------------------------------------- ; ?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 .text:CODE(2) PUBLIC __iar_program_start EXTERN ?main CODE32 __iar_program_start: LDR pc, =NextInst NextInst ; Reset all Peripheral Clocks ; This is usefull only when using debugger to Reset\Run the application #ifdef SMI_Bank0_EN LDR r0, =0x01000000 ; Disable peripherals clock (except GPIO) #else LDR r0, =0x00000000 ; Disable peripherals clock #endif LDR r1, =MRCC_PCLKEN_Addr STR r0, [r1] #ifdef SMI_Bank0_EN LDR r0, =0x1875623F ; Peripherals kept under reset (except GPIO) #else LDR r0, =0x1975623F ; Peripherals kept under reset #endif STR r0, [r1,#4] MOV r0, #0 NOP ; Wait NOP NOP NOP STR r0, [r1,#4] ; Disable peripherals reset ; 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) ; End of FIQ_STACK MSR CPSR_c, #Mode_IRQ|I_Bit|F_Bit ; No interrupts ldr sp,=SFE(IRQ_STACK) ; End of IRQ_STACK MSR CPSR_c, #Mode_ABT|I_Bit|F_Bit ; No interrupts ldr sp,=SFE(ABT_STACK) ; End of ABT_STACK MSR CPSR_c, #Mode_UND|I_Bit|F_Bit ; No interrupts ldr sp,=SFE(UND_STACK) ; End of UND_STACK MSR CPSR_c, #Mode_SVC|I_Bit|F_Bit ; No interrupts ldr sp,=SFE(SVC_STACK) ; End of SVC_STACK ; ------------------------------------------------------------------------------ ; Description : Enable SMI Bank0: enable GPIOs clock in MRCC_PCLKEN register, ; enable SMI alternate function in GPIO_REMAP register and enable ; Bank0 in SMI_CR1 register. ; ------------------------------------------------------------------------------ #ifdef SMI_Bank0_EN MOV r0, #0x01000000 LDR r1, =MRCC_PCLKEN_Addr STR r0, [r1] ; Enable GPIOs clock LDR r1, =GPIOREMAP0R_Addr MOV r0, #SMI_EN_Mask LDR r2, [r1] ORR r2, r2, r0 STR r2, [r1] ; Enable SMI alternate function LDR r0, =0x251 ; SMI Bank0 enabled, Prescaler = 2, Deselect Time = 5 LDR r1, =SMI_CR1_Addr STR r0, [r1] ; Configure CR1 register LDR r0, =0x00 STR r0, [r1,#4] ; Reset CR2 register #endif ; ------------------------------------------------------------------------------ ; Description : Remapping SRAM at address 0x00 after the application has ; started executing. ; ------------------------------------------------------------------------------ #ifdef Remap_SRAM MOV r0, #SRAM_mask LDR r1, =CFG_GLCONF_Addr LDR r2, [r1] ; Read GLCONF Register BIC r2, r2, #0x03 ; Reset the SW_BOOT bits ORR r2, r2, r0 ; Change the SW_BOOT bits STR r2, [r1] ; Write GLCONF Register #endif ;------------------------------------------------------------------------------- ;Description : Initialize the EIC as following : ; - IRQ disabled ; - FIQ disabled ; - IVR contains the load PC opcode ; - All channels are disabled ; - All channels priority equal to 0 ; - All SIR registers contains offset to the related IRQ table entry ;------------------------------------------------------------------------------- #ifdef EIC_INIT LDR r3, =EIC_Base_addr LDR r4, =0x00000000 STR r4, [r3, #ICR_off_addr] ; Disable FIQ and IRQ STR r4, [r3, #IER_off_addr] ; Disable all interrupts channels LDR r4, =0xFFFFFFFF STR r4, [r3, #IPR_off_addr] ; Clear all IRQ pending bits LDR r4, =0x18 STR r4, [r3, #FIR_off_addr] ; Disable FIQ channels and clear FIQ pending bits LDR r4, =0x00000000 STR r4, [r3, #CIPR_off_addr] ; Reset the current priority register LDR r4, =0xE59F0000 ; Write the LDR pc,pc,#offset.. STR r4, [r3, #IVR_off_addr] ; ..instruction code in IVR[31:16] LDR r2,= 32 ; 32 Channel to initialize LDR r0, =WAKUP_Addr ; Read the address of the IRQs address table LDR r1, =0x00000FFF AND r0,r0,r1 LDR r5,=SIR0_off_addr ; Read SIR0 address SUB r4,r0,#8 ; subtract 8 for prefetch LDR r1, =0xF7E8 ; add the offset to the 0x00 address.. ; ..(IVR address + 7E8 = 0x00) ; 0xF7E8 used to complete the LDR pc,offset opcode ADD r1,r4,r1 ; compute the jump offset EIC_INI MOV r4, r1, LSL #16 ; Left shift the result STR r4, [r3, r5] ; Store the result in SIRx register ADD r1, r1, #4 ; Next IRQ address ADD r5, r5, #4 ; Next SIR SUBS r2, r2, #1 ; Decrement the number of SIR registers to initialize BNE EIC_INI ; If more then continue #endif ; --- Branch to C Library entry point IMPORT ?main B ?main ; use B not BL, because an application will never return this way LTORG END ;******************* (C) COPYRIGHT 2006 STMicroelectronics *****END OF FILE*****