/***********************************************************************/
/*  This file is part of the CA ARM C Compiler package                 */
/*  Copyright KEIL ELEKTRONIK GmbH 2002-2004                           */
/***********************************************************************/
/*                                                                     */
/*  STARTUP.S:  Startup file for ADI ADuC702x device series            */
/*                                                                     */
/***********************************************************************/


/* 
//*** <<< Use Configuration Wizard in Context Menu >>> *** 
*/


// *** Startup Code (executed after Reset) ***


// 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 */


/*
// <h> Stack Configuration (Stack Sizes in Bytes)
//   <o0> Undefined Mode      <0x0-0xFFFFFFFF>
//   <o1> Supervisor Mode     <0x0-0xFFFFFFFF>
//   <o2> Abort Mode          <0x0-0xFFFFFFFF>
//   <o3> Fast Interrupt Mode <0x0-0xFFFFFFFF>
//   <o4> Interrupt Mode      <0x0-0xFFFFFFFF>
//   <o5> User/System Mode    <0x0-0xFFFFFFFF>
// </h>
*/
        UND_Stack_Size  EQU     0x00000004
        SVC_Stack_Size  EQU     0x00000004
        ABT_Stack_Size  EQU     0x00000004
        FIQ_Stack_Size  EQU     0x00000004
        IRQ_Stack_Size  EQU     0x00000080
        USR_Stack_Size  EQU     0x00000400

AREA   STACK, DATA, READWRITE, ALIGN=2
        DS   (USR_Stack_Size+3)&~3  ; Stack for User/System Mode 
        DS   (IRQ_Stack_Size+3)&~3  ; Stack for Interrupt Mode
        DS   (FIQ_Stack_Size+3)&~3  ; Stack for Fast Interrupt Mode 
        DS   (ABT_Stack_Size+3)&~3  ; Stack for Abort Mode
        DS   (SVC_Stack_Size+3)&~3  ; Stack for Supervisor Mode
        DS   (UND_Stack_Size+3)&~3  ; Stack for Undefined Mode
Top_Stack:


// MMR definitions
        MMR_BASE        EQU     0xFFFF0000      ; MMR Base Address
        POWKEY1_OFFSET  EQU         0x0404
        POWCON_OFFSET   EQU         0x0408
        POWKEY2_OFFSET  EQU         0x040C

// <e> PLL Setup
//   <o1.0..2>  CD: PLL Multiplier Selection
//               <0-7>
//               <i> CD Value
//   <o1.3>     FINT: Fast Interrupt
//               <0-1>
//               <i> Switches to CD0 for FIQ
// </e>
        PLL_SETUP       EQU     1
        PLLCFG_Val      EQU     0x00000000


// Startup Code must be linked at address which it expects to run.
									
AREA   STARTUPCODE, CODE, AT 0x00080000
       PUBLIC  __startup

       EXTERN  CODE32 (?C?INIT)

__startup       PROC    CODE32

// Pre-defined interrupt handlers that may be directly 
// overwritten by C interrupt functions
EXTERN CODE32 (Undef_Handler?A)
EXTERN CODE32 (SWI_Handler?A)
EXTERN CODE32 (PAbt_Handler?A)
EXTERN CODE32 (DAbt_Handler?A)
EXTERN CODE32 (IRQ_Handler?A)
EXTERN CODE32 (FIQ_Handler?A)
EXTERN CODE32 (My_IRQ_Function?A)

// Exception Vectors
// Mapped to Address 0.
// Absolute addressing mode must be used.

Vectors:        LDR     PC,Reset_Addr         
                LDR     PC,Undef_Addr
                LDR     PC,SWI_Addr
                LDR     PC,PAbt_Addr
                LDR     PC,DAbt_Addr
                NOP                            /* Reserved Vector */
                LDR     PC,IRQ_Addr
                LDR     PC,FIQ_Addr

Reset_Addr:     DD      Reset_Handler
Undef_Addr:     DD      Undef_Handler?A
SWI_Addr:       DD      SWI_Handler?A
PAbt_Addr:      DD      PAbt_Handler?A
DAbt_Addr:      DD      DAbt_Handler?A
                DD      0                      /* Reserved Address */
IRQ_Addr:       DD      IRQ_Handler?A
FIQ_Addr:       DD      FIQ_Handler?A


// Reset Handler

Reset_Handler:  


// Setup PLL
IF (PLL_SETUP != 0)
                LDR     R0, =MMR_BASE
                MOV     R1, #0x01         
                STR     R1, [R0,#POWKEY1_OFFSET]          
                MOV     R1, #PLLCFG_Val      
                STR     R1, [R0,#POWCON_OFFSET]    
                MOV     R1, #0xF4
                STR     R1, [R0,#POWKEY2_OFFSET]
ENDIF   ; PLL_SETUP


// Setup Stack for each mode
                LDR     R0, =Top_Stack

// Enter Undefined Instruction Mode and set its Stack Pointer
                MSR     CPSR_c, #Mode_UND|I_Bit|F_Bit
                MOV     SP, R0
                SUB     R0, R0, #UND_Stack_Size

// Enter Abort Mode and set its Stack Pointer
                MSR     CPSR_c, #Mode_ABT|I_Bit|F_Bit
                MOV     SP, R0
                SUB     R0, R0, #ABT_Stack_Size

// Enter FIQ Mode and set its Stack Pointer
                MSR     CPSR_c, #Mode_FIQ|I_Bit|F_Bit
                MOV     SP, R0
                SUB     R0, R0, #FIQ_Stack_Size

// Enter IRQ Mode and set its Stack Pointer
                MSR     CPSR_c, #Mode_IRQ|I_Bit|F_Bit
                MOV     SP, R0
                SUB     R0, R0, #IRQ_Stack_Size

// Enter Supervisor Mode and set its Stack Pointer
                MSR     CPSR_c, #Mode_SVC|I_Bit|F_Bit
                MOV     SP, R0
                SUB     R0, R0, #SVC_Stack_Size

// Enter User Mode and set its Stack Pointer
                MSR     CPSR_c, #Mode_USR
                MOV     SP, R0

// Enter the C code
                LDR     R0,=?C?INIT
                TST     R0,#1       ; Bit-0 set: main is Thumb
                LDREQ   LR,=exit?A  ; ARM Mode
                LDRNE   LR,=exit?T  ; Thumb Mode
                BX      R0
                ENDP

PUBLIC exit?A
exit?A          PROC    CODE32
                B       exit?A
                ENDP

PUBLIC exit?T
exit?T          PROC    CODE16
                B       exit?T
                ENDP

                END