518 lines
		
	
	
		
			17 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
		
		
			
		
	
	
			518 lines
		
	
	
		
			17 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
|  | ;/*****************************************************************************/
 | ||
|  | ;/* SAM7.S: Startup file for Atmel AT91SAM7 device series                     */
 | ||
|  | ;/*****************************************************************************/
 | ||
|  | ;/* <<< Use Configuration Wizard in Context Menu >>>                          */ 
 | ||
|  | ;/*****************************************************************************/
 | ||
|  | ;/* This file is part of the uVision/ARM development tools.                   */
 | ||
|  | ;/* Copyright (c) 2005-2006 Keil Software. All rights reserved.               */
 | ||
|  | ;/* This software may only be used under the terms of a valid, current,       */
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|  | ;/* end user licence from KEIL for a compatible version of KEIL software      */
 | ||
|  | ;/* development tools. Nothing else gives you the right to use this software. */
 | ||
|  | ;/*****************************************************************************/
 | ||
|  | 
 | ||
|  | 
 | ||
|  | ;/*
 | ||
|  | ; *  The SAM7.S code is executed after CPU Reset. This file may be 
 | ||
|  | ; *  translated with the following SET symbols. In uVision these SET 
 | ||
|  | ; *  symbols are entered under Options - ASM - Define.
 | ||
|  | ; *
 | ||
|  | ; *  REMAP: when set the startup code remaps exception vectors from
 | ||
|  | ; *  on-chip RAM to address 0.
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|  | ; *
 | ||
|  | ; *  RAM_INTVEC: when set the startup code copies exception vectors 
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|  | ; *  from on-chip Flash to on-chip RAM.
 | ||
|  | ; */
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|  | 
 | ||
|  | 
 | ||
|  | ; Standard definitions of Mode bits and Interrupt (I & F) flags in PSRs
 | ||
|  | 
 | ||
|  | ; 2009-12-28	MingBai		Bug fix (USR mode stack removed).
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|  | ; 2009-12-29	MingBai		Merge svc and irq stack, add abort handler.
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|  | 
 | ||
|  | 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
 | ||
|  | 
 | ||
|  | 
 | ||
|  | ; Internal Memory Base Addresses
 | ||
|  | FLASH_BASE      EQU     0x00100000    | ||
|  | RAM_BASE        EQU     0x00200000 | ||
|  | 
 | ||
|  | 
 | ||
|  | ;// <h> Stack Configuration (Stack Sizes in Bytes)
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|  | ;//   <o0> Undefined Mode      <0x0-0xFFFFFFFF:8>
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|  | ;//   <o1> Supervisor Mode     <0x0-0xFFFFFFFF:8>
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|  | ;//   <o2> Abort Mode          <0x0-0xFFFFFFFF:8>
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|  | ;//   <o3> Fast Interrupt Mode <0x0-0xFFFFFFFF:8>
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|  | ;//   <o4> Interrupt Mode      <0x0-0xFFFFFFFF:8>
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|  | ;//   <o5> User/System Mode    <0x0-0xFFFFFFFF:8>
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|  | ;// </h>
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|  | 
 | ||
|  | UND_Stack_Size  EQU     0x00000000 | ||
|  | SVC_Stack_Size  EQU     0x00000000 | ||
|  | ABT_Stack_Size  EQU     0x00000000 | ||
|  | FIQ_Stack_Size  EQU     0x00000000 | ||
|  | IRQ_Stack_Size  EQU     0x00000100 | ||
|  | USR_Stack_Size  EQU     0x00000000 | ||
|  | 
 | ||
|  | ISR_Stack_Size  EQU     (UND_Stack_Size + SVC_Stack_Size + ABT_Stack_Size + \ | ||
|  |                          FIQ_Stack_Size + IRQ_Stack_Size) | ||
|  | 
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|  |                 AREA    STACK, NOINIT, READWRITE, ALIGN=3 | ||
|  | 
 | ||
|  | Stack_Mem       SPACE   USR_Stack_Size | ||
|  | __initial_sp    SPACE   ISR_Stack_Size | ||
|  | Stack_Top | ||
|  | 
 | ||
|  | 
 | ||
|  | ;// <h> Heap Configuration
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|  | ;//   <o>  Heap Size (in Bytes) <0x0-0xFFFFFFFF>
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|  | ;// </h>
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|  | 
 | ||
|  | Heap_Size       EQU     0x00000000 | ||
|  | 
 | ||
|  |                 AREA    HEAP, NOINIT, READWRITE, ALIGN=3 | ||
|  | __heap_base | ||
|  | Heap_Mem        SPACE   Heap_Size | ||
|  | __heap_limit | ||
|  | 
 | ||
|  | 
 | ||
|  | ; Reset Controller (RSTC) definitions
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|  | RSTC_BASE       EQU     0xFFFFFD00      ; RSTC Base Address
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|  | RSTC_MR         EQU     0x08            ; RSTC_MR Offset
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|  | 
 | ||
|  | ;/*
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|  | ;// <e> Reset Controller (RSTC)
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|  | ;//   <o1.0>     URSTEN: User Reset Enable
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|  | ;//              <i> Enables NRST Pin to generate Reset
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|  | ;//   <o1.8..11> ERSTL: External Reset Length <0-15>
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|  | ;//              <i> External Reset Time in 2^(ERSTL+1) Slow Clock Cycles
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|  | ;// </e>
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|  | ;*/
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|  | RSTC_SETUP      EQU     1 | ||
|  | RSTC_MR_Val     EQU     0xA5000401 | ||
|  | 
 | ||
|  | 
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|  | ; Embedded Flash Controller (EFC) definitions
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|  | EFC_BASE        EQU     0xFFFFFF00      ; EFC Base Address
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|  | EFC0_FMR        EQU     0x60            ; EFC0_FMR Offset
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|  | EFC1_FMR        EQU     0x70            ; EFC1_FMR Offset
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|  | 
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|  | ;// <e> Embedded Flash Controller 0 (EFC0)
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|  | ;//   <o1.16..23> FMCN: Flash Microsecond Cycle Number <0-255>
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|  | ;//               <i> Number of Master Clock Cycles in 1us
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|  | ;//   <o1.8..9>   FWS: Flash Wait State
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|  | ;//               <0=> Read: 1 cycle / Write: 2 cycles
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|  | ;//               <1=> Read: 2 cycle / Write: 3 cycles
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|  | ;//               <2=> Read: 3 cycle / Write: 4 cycles
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|  | ;//               <3=> Read: 4 cycle / Write: 4 cycles
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|  | ;// </e>
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|  | EFC0_SETUP      EQU     1 | ||
|  | EFC0_FMR_Val    EQU     0x00320100 | ||
|  | 
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|  | ;// <e> Embedded Flash Controller 1 (EFC1)
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|  | ;//   <o1.16..23> FMCN: Flash Microsecond Cycle Number <0-255>
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|  | ;//               <i> Number of Master Clock Cycles in 1us
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|  | ;//   <o1.8..9>   FWS: Flash Wait State
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|  | ;//               <0=> Read: 1 cycle / Write: 2 cycles
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|  | ;//               <1=> Read: 2 cycle / Write: 3 cycles
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|  | ;//               <2=> Read: 3 cycle / Write: 4 cycles
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|  | ;//               <3=> Read: 4 cycle / Write: 4 cycles
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|  | ;// </e>
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|  | EFC1_SETUP      EQU     0 | ||
|  | EFC1_FMR_Val    EQU     0x00320100 | ||
|  | 
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|  | 
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|  | ; Watchdog Timer (WDT) definitions
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|  | WDT_BASE        EQU     0xFFFFFD40      ; WDT Base Address
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|  | WDT_MR          EQU     0x04            ; WDT_MR Offset
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|  | 
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|  | ;// <e> Watchdog Timer (WDT)
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|  | ;//   <o1.0..11>  WDV: Watchdog Counter Value <0-4095>
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|  | ;//   <o1.16..27> WDD: Watchdog Delta Value <0-4095>
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|  | ;//   <o1.12>     WDFIEN: Watchdog Fault Interrupt Enable
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|  | ;//   <o1.13>     WDRSTEN: Watchdog Reset Enable
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|  | ;//   <o1.14>     WDRPROC: Watchdog Reset Processor
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|  | ;//   <o1.28>     WDDBGHLT: Watchdog Debug Halt
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|  | ;//   <o1.29>     WDIDLEHLT: Watchdog Idle Halt
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|  | ;//   <o1.15>     WDDIS: Watchdog Disable
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|  | ;// </e>
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|  | WDT_SETUP       EQU     1 | ||
|  | WDT_MR_Val      EQU     0x00008000 | ||
|  | 
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|  | 
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|  | ; Power Mangement Controller (PMC) definitions
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|  | PMC_BASE        EQU     0xFFFFFC00      ; PMC Base Address
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|  | PMC_MOR         EQU     0x20            ; PMC_MOR Offset
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|  | PMC_MCFR        EQU     0x24            ; PMC_MCFR Offset
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|  | PMC_PLLR        EQU     0x2C            ; PMC_PLLR Offset
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|  | PMC_MCKR        EQU     0x30            ; PMC_MCKR Offset
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|  | PMC_SR          EQU     0x68            ; PMC_SR Offset
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|  | PMC_MOSCEN      EQU     (1<<0)          ; Main Oscillator Enable
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|  | PMC_OSCBYPASS   EQU     (1<<1)          ; Main Oscillator Bypass
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|  | PMC_OSCOUNT     EQU     (0xFF<<8)       ; Main OScillator Start-up Time
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|  | PMC_DIV         EQU     (0xFF<<0)       ; PLL Divider
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|  | PMC_PLLCOUNT    EQU     (0x3F<<8)       ; PLL Lock Counter
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|  | PMC_OUT         EQU     (0x03<<14)      ; PLL Clock Frequency Range
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|  | PMC_MUL         EQU     (0x7FF<<16)     ; PLL Multiplier
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|  | PMC_USBDIV      EQU     (0x03<<28)      ; USB Clock Divider
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|  | PMC_CSS         EQU     (3<<0)          ; Clock Source Selection
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|  | PMC_PRES        EQU     (7<<2)          ; Prescaler Selection
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|  | PMC_MOSCS       EQU     (1<<0)          ; Main Oscillator Stable
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|  | PMC_LOCK        EQU     (1<<2)          ; PLL Lock Status
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|  | PMC_MCKRDY      EQU     (1<<3)          ; Master Clock Status
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|  | 
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|  | ;// <e> Power Mangement Controller (PMC)
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|  | ;//   <h> Main Oscillator
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|  | ;//     <o1.0>      MOSCEN: Main Oscillator Enable
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|  | ;//     <o1.1>      OSCBYPASS: Oscillator Bypass
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|  | ;//     <o1.8..15>  OSCCOUNT: Main Oscillator Startup Time <0-255>
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|  | ;//   </h>
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|  | ;//   <h> Phase Locked Loop (PLL)
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|  | ;//     <o2.0..7>   DIV: PLL Divider <0-255>
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|  | ;//     <o2.16..26> MUL: PLL Multiplier <0-2047>
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|  | ;//                 <i> PLL Output is multiplied by MUL+1
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|  | ;//     <o2.14..15> OUT: PLL Clock Frequency Range
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|  | ;//                 <0=> 80..160MHz  <1=> Reserved
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|  | ;//                 <2=> 150..220MHz <3=> Reserved
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|  | ;//     <o2.8..13>  PLLCOUNT: PLL Lock Counter <0-63>
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|  | ;//     <o2.28..29> USBDIV: USB Clock Divider
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|  | ;//                 <0=> None  <1=> 2  <2=> 4  <3=> Reserved
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|  | ;//   </h>
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|  | ;//   <o3.0..1>   CSS: Clock Source Selection
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|  | ;//               <0=> Slow Clock
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|  | ;//               <1=> Main Clock
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|  | ;//               <2=> Reserved
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|  | ;//               <3=> PLL Clock
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|  | ;//   <o3.2..4>   PRES: Prescaler
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|  | ;//               <0=> None
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|  | ;//               <1=> Clock / 2    <2=> Clock / 4
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|  | ;//               <3=> Clock / 8    <4=> Clock / 16
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|  | ;//               <5=> Clock / 32   <6=> Clock / 64
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|  | ;//               <7=> Reserved
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|  | ;// </e>
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|  | PMC_SETUP       EQU     1 | ||
|  | PMC_MOR_Val     EQU     0x00000601 | ||
|  | PMC_PLLR_Val    EQU     0x00191C05 | ||
|  | PMC_MCKR_Val    EQU     0x00000007 | ||
|  | 
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|  | 
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|  |                 PRESERVE8 | ||
|  |                  | ||
|  | 
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|  | ; Area Definition and Entry Point
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|  | ;  Startup Code must be linked first at Address at which it expects to run.
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|  | 
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|  |                 AREA    RESET, CODE, READONLY | ||
|  |                 ARM | ||
|  | 
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|  | 
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|  | ; Exception Vectors
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|  | ;  Mapped to Address 0.
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|  | ;  Absolute addressing mode must be used.
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|  | ;  Dummy Handlers are implemented as infinite loops which can be modified.
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|  | 
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|  | Vectors         LDR     PC,Reset_Addr          | ||
|  |                 LDR     PC,Undef_Addr | ||
|  |                 LDR     PC,SWI_Addr | ||
|  |                 LDR     PC,PAbt_Addr | ||
|  |                 LDR     PC,DAbt_Addr | ||
|  |                 NOP                            ; Reserved Vector
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|  |                 LDR     PC,IRQ_Addr | ||
|  |                 LDR     PC,FIQ_Addr | ||
|  | 
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|  | Reset_Addr      DCD     Reset_Handler | ||
|  | Undef_Addr      DCD     Undef_Handler | ||
|  | SWI_Addr        DCD     SWI_Handler | ||
|  | PAbt_Addr       DCD     PAbt_Handler | ||
|  | DAbt_Addr       DCD     DAbt_Handler | ||
|  |                 DCD     0                      ; Reserved Address
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|  | IRQ_Addr        DCD     IRQ_Handler | ||
|  | FIQ_Addr        DCD     FIQ_Handler | ||
|  | 
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|  | Undef_Handler   B       Undef_Handler | ||
|  | SWI_Handler     B       SWI_Handler | ||
|  | PAbt_Handler    B       Abort_Handler | ||
|  | DAbt_Handler    B       Abort_Handler | ||
|  | FIQ_Handler     B       FIQ_Handler | ||
|  | 
 | ||
|  | 
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|  | ; Reset Handler
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|  | 
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|  |                 EXPORT  Reset_Handler | ||
|  | Reset_Handler    | ||
|  | 
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|  | 
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|  | ; Setup RSTC
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|  |                 IF      RSTC_SETUP != 0 | ||
|  |                 LDR     R0, =RSTC_BASE | ||
|  |                 LDR     R1, =RSTC_MR_Val | ||
|  |                 STR     R1, [R0, #RSTC_MR] | ||
|  |                 ENDIF | ||
|  | 
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|  | 
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|  | ; Setup EFC0
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|  |                 IF      EFC0_SETUP != 0 | ||
|  |                 LDR     R0, =EFC_BASE | ||
|  |                 LDR     R1, =EFC0_FMR_Val | ||
|  |                 STR     R1, [R0, #EFC0_FMR] | ||
|  |                 ENDIF | ||
|  | 
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|  | ; Setup EFC1
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|  |                 IF      EFC1_SETUP != 0 | ||
|  |                 LDR     R0, =EFC_BASE | ||
|  |                 LDR     R1, =EFC1_FMR_Val | ||
|  |                 STR     R1, [R0, #EFC1_FMR] | ||
|  |                 ENDIF | ||
|  | 
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|  | ; Setup WDT
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|  |                 IF      WDT_SETUP != 0 | ||
|  |                 LDR     R0, =WDT_BASE | ||
|  |                 LDR     R1, =WDT_MR_Val | ||
|  |                 STR     R1, [R0, #WDT_MR] | ||
|  |                 ENDIF | ||
|  | 
 | ||
|  | 
 | ||
|  | ; Setup PMC
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|  |                 IF      PMC_SETUP != 0 | ||
|  |                 LDR     R0, =PMC_BASE | ||
|  | 
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|  | ;  Setup Main Oscillator
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|  |                 LDR     R1, =PMC_MOR_Val | ||
|  |                 STR     R1, [R0, #PMC_MOR] | ||
|  | 
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|  | ;  Wait until Main Oscillator is stablilized
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|  |                 IF      (PMC_MOR_Val:AND:PMC_MOSCEN) != 0 | ||
|  | MOSCS_Loop      LDR     R2, [R0, #PMC_SR] | ||
|  |                 ANDS    R2, R2, #PMC_MOSCS | ||
|  |                 BEQ     MOSCS_Loop | ||
|  |                 ENDIF | ||
|  | 
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|  | ;  Setup the PLL
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|  |                 IF      (PMC_PLLR_Val:AND:PMC_MUL) != 0 | ||
|  |                 LDR     R1, =PMC_PLLR_Val | ||
|  |                 STR     R1, [R0, #PMC_PLLR] | ||
|  | 
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|  | ;  Wait until PLL is stabilized
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|  | PLL_Loop        LDR     R2, [R0, #PMC_SR] | ||
|  |                 ANDS    R2, R2, #PMC_LOCK | ||
|  |                 BEQ     PLL_Loop | ||
|  |                 ENDIF | ||
|  | 
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|  | ;  Select Clock
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|  |                 IF      (PMC_MCKR_Val:AND:PMC_CSS) == 1     ; Main Clock Selected
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|  |                 LDR     R1, =PMC_MCKR_Val | ||
|  |                 AND     R1, #PMC_CSS | ||
|  |                 STR     R1, [R0, #PMC_MCKR] | ||
|  | WAIT_Rdy1       LDR     R2, [R0, #PMC_SR] | ||
|  |                 ANDS    R2, R2, #PMC_MCKRDY | ||
|  |                 BEQ     WAIT_Rdy1 | ||
|  |                 LDR     R1, =PMC_MCKR_Val | ||
|  |                 STR     R1, [R0, #PMC_MCKR] | ||
|  | WAIT_Rdy2       LDR     R2, [R0, #PMC_SR] | ||
|  |                 ANDS    R2, R2, #PMC_MCKRDY | ||
|  |                 BEQ     WAIT_Rdy2 | ||
|  |                 ELIF    (PMC_MCKR_Val:AND:PMC_CSS) == 3     ; PLL  Clock Selected
 | ||
|  |                 LDR     R1, =PMC_MCKR_Val | ||
|  |                 AND     R1, #PMC_PRES | ||
|  |                 STR     R1, [R0, #PMC_MCKR] | ||
|  | WAIT_Rdy1       LDR     R2, [R0, #PMC_SR] | ||
|  |                 ANDS    R2, R2, #PMC_MCKRDY | ||
|  |                 BEQ     WAIT_Rdy1 | ||
|  |                 LDR     R1, =PMC_MCKR_Val | ||
|  |                 STR     R1, [R0, #PMC_MCKR] | ||
|  | WAIT_Rdy2       LDR     R2, [R0, #PMC_SR] | ||
|  |                 ANDS    R2, R2, #PMC_MCKRDY | ||
|  |                 BEQ     WAIT_Rdy2 | ||
|  |                 ENDIF   ; Select Clock
 | ||
|  |                 ENDIF   ; PMC_SETUP
 | ||
|  | 
 | ||
|  | 
 | ||
|  | ; Copy Exception Vectors to Internal RAM
 | ||
|  | 
 | ||
|  |                 IF      :DEF:RAM_INTVEC | ||
|  |                 ADR     R8, Vectors         ; Source
 | ||
|  |                 LDR     R9, =RAM_BASE       ; Destination
 | ||
|  |                 LDMIA   R8!, {R0-R7}        ; Load Vectors 
 | ||
|  |                 STMIA   R9!, {R0-R7}        ; Store Vectors 
 | ||
|  |                 LDMIA   R8!, {R0-R7}        ; Load Handler Addresses 
 | ||
|  |                 STMIA   R9!, {R0-R7}        ; Store Handler Addresses
 | ||
|  |                 ENDIF | ||
|  | 
 | ||
|  | 
 | ||
|  | ; Remap on-chip RAM to address 0
 | ||
|  | 
 | ||
|  | MC_BASE EQU     0xFFFFFF00      ; MC Base Address
 | ||
|  | MC_RCR  EQU     0x00            ; MC_RCR Offset
 | ||
|  | 
 | ||
|  |                 IF      :DEF:REMAP | ||
|  |                 LDR     R0, =MC_BASE | ||
|  |                 MOV     R1, #1 | ||
|  |                 STR     R1, [R0, #MC_RCR]   ; Remap | ||
|  |                 ENDIF | ||
|  | 
 | ||
|  | 
 | ||
|  | ; Setup Stack for each mode
 | ||
|  | 
 | ||
|  |                 LDR     R0, =Stack_Top | ||
|  | 
 | ||
|  | ;  Enter Undefined Instruction Mode and set its Stack Pointer
 | ||
|  |                 MSR     CPSR_c, #Mode_UND:OR:I_Bit:OR:F_Bit | ||
|  |                 MOV     SP, R0 | ||
|  |                 ;SUB     R0, R0, #UND_Stack_Size
 | ||
|  | 
 | ||
|  | ;  Enter Abort Mode and set its Stack Pointer
 | ||
|  |                 MSR     CPSR_c, #Mode_ABT:OR:I_Bit:OR:F_Bit | ||
|  |                 MOV     SP, R0 | ||
|  |                 ;SUB     R0, R0, #ABT_Stack_Size
 | ||
|  | 
 | ||
|  | ;  Enter FIQ Mode and set its Stack Pointer
 | ||
|  |                 MSR     CPSR_c, #Mode_FIQ:OR:I_Bit:OR:F_Bit | ||
|  |                 MOV     SP, R0 | ||
|  |                 ;SUB     R0, R0, #FIQ_Stack_Size
 | ||
|  | 
 | ||
|  | ;  Enter IRQ Mode and set its Stack Pointer
 | ||
|  |                 MSR     CPSR_c, #Mode_IRQ:OR:I_Bit:OR:F_Bit | ||
|  |                 MOV     SP, R0 | ||
|  |                 ;SUB     R0, R0, #IRQ_Stack_Size
 | ||
|  | 
 | ||
|  | ;  Enter Supervisor Mode and set its Stack Pointer
 | ||
|  |                 MSR     CPSR_c, #Mode_SVC:OR:I_Bit:OR:F_Bit | ||
|  |                 MOV     SP, R0 | ||
|  |                 ; SUB     R0, R0, #SVC_Stack_Size
 | ||
|  | 
 | ||
|  | ;  Enter User Mode and set its Stack Pointer
 | ||
|  |                 ; MSR     CPSR_c, #Mode_USR
 | ||
|  |                 IF      :DEF:__MICROLIB | ||
|  | 
 | ||
|  |                 EXPORT __initial_sp | ||
|  | 
 | ||
|  |                 ELSE | ||
|  | 
 | ||
|  | 				; No usr mode stack here.
 | ||
|  |                 ;MOV     SP, R0
 | ||
|  |                 ;SUB     SL, SP, #USR_Stack_Size
 | ||
|  | 
 | ||
|  |                 ENDIF | ||
|  | 
 | ||
|  | 
 | ||
|  | ; Enter the C code
 | ||
|  | 
 | ||
|  |                 IMPORT  __main | ||
|  |                 LDR     R0, =__main | ||
|  |                 BX      R0 | ||
|  | 
 | ||
|  | 				IMPORT rt_interrupt_enter | ||
|  | 				IMPORT rt_interrupt_leave | ||
|  | 				IMPORT rt_thread_switch_interrupt_flag | ||
|  | 				IMPORT rt_interrupt_from_thread | ||
|  | 				IMPORT rt_interrupt_to_thread | ||
|  | 				IMPORT rt_hw_trap_irq | ||
|  | 				IMPORT rt_hw_trap_abort | ||
|  | 				IMPORT rt_interrupt_nest | ||
|  | 
 | ||
|  | Abort_Handler	PROC | ||
|  | 				EXPORT	Abort_Handler | ||
|  | 				stmfd	sp!, {r0-r12,lr} | ||
|  | 	 			LDR	r0, =rt_interrupt_nest | ||
|  | 				LDR	r1, [r0] | ||
|  | 				CMP	r1, #0 | ||
|  | DeadLoop		BHI	DeadLoop    ; Abort happened in irq mode, halt system.
 | ||
|  | 				bl	rt_interrupt_enter | ||
|  | 				bl	rt_hw_trap_abort | ||
|  | 				bl	rt_interrupt_leave | ||
|  | 				b	SWITCH | ||
|  | 				ENDP | ||
|  | 				 | ||
|  | IRQ_Handler		PROC | ||
|  | 				EXPORT IRQ_Handler | ||
|  | 				STMFD	sp!, {r0-r12,lr} | ||
|  | 				BL	rt_interrupt_enter | ||
|  | 				BL	rt_hw_trap_irq | ||
|  | 				BL	rt_interrupt_leave | ||
|  | 
 | ||
|  | 				; if rt_thread_switch_interrupt_flag set, jump to
 | ||
|  | 				; rt_hw_context_switch_interrupt_do and don't return
 | ||
|  | SWITCH			LDR	r0, =rt_thread_switch_interrupt_flag | ||
|  | 				LDR	r1, [r0] | ||
|  | 				CMP	r1, #1 | ||
|  | 				BEQ	rt_hw_context_switch_interrupt_do | ||
|  | 
 | ||
|  | 				LDMFD	sp!, {r0-r12,lr} | ||
|  | 				SUBS	pc, lr, #4 | ||
|  | 				ENDP | ||
|  | 
 | ||
|  | ; /*
 | ||
|  | ; * void rt_hw_context_switch_interrupt_do(rt_base_t flag)
 | ||
|  | ; */
 | ||
|  | rt_hw_context_switch_interrupt_do	PROC | ||
|  | 				EXPORT rt_hw_context_switch_interrupt_do | ||
|  | 				MOV		r1,  #0			; clear flag
 | ||
|  | 				STR		r1,  [r0] | ||
|  | 
 | ||
|  | 				LDMFD	sp!, {r0-r12,lr}; reload saved registers
 | ||
|  | 				STMFD	sp!, {r0-r3}	; save r0-r3
 | ||
|  | 				MOV		r1,  sp | ||
|  | 				ADD		sp,  sp, #16	; restore sp
 | ||
|  | 				SUB		r2,  lr, #4		; save old task's pc to r2
 | ||
|  | 
 | ||
|  | 				MRS		r3,  spsr		; get cpsr of interrupt thread
 | ||
|  | 
 | ||
|  | 				; switch to SVC mode and no interrupt
 | ||
|  |                 MSR     cpsr_c, #I_Bit|F_Bit|Mode_SVC | ||
|  | 
 | ||
|  | 				STMFD	sp!, {r2}		; push old task's pc
 | ||
|  | 				STMFD	sp!, {r4-r12,lr}; push old task's lr,r12-r4
 | ||
|  | 				MOV		r4,  r1			; Special optimised code below
 | ||
|  | 				MOV		r5,  r3 | ||
|  | 				LDMFD	r4!, {r0-r3} | ||
|  | 				STMFD	sp!, {r0-r3}	; push old task's r3-r0
 | ||
|  | 				STMFD	sp!, {r5}		; push old task's cpsr
 | ||
|  | 				MRS		r4,  spsr | ||
|  | 				STMFD	sp!, {r4}		; push old task's spsr
 | ||
|  | 
 | ||
|  | 				LDR		r4,  =rt_interrupt_from_thread | ||
|  | 				LDR		r5,  [r4] | ||
|  | 				STR		sp,  [r5]		; store sp in preempted tasks's TCB
 | ||
|  | 
 | ||
|  | 				LDR		r6,  =rt_interrupt_to_thread | ||
|  | 				LDR		r6,  [r6] | ||
|  | 				LDR		sp,  [r6]		; get new task's stack pointer
 | ||
|  | 			 | ||
|  | 				LDMFD	sp!, {r4}		; pop new task's spsr
 | ||
|  | 				MSR		spsr_cxsf, r4 | ||
|  | 				LDMFD	sp!, {r4}		; pop new task's psr
 | ||
|  | 				MSR		cpsr_cxsf, r4 | ||
|  | 
 | ||
|  | 				LDMFD	sp!, {r0-r12,lr,pc}	; pop new task's r0-r12,lr & pc
 | ||
|  | 				ENDP | ||
|  | 
 | ||
|  |                 IF      :DEF:__MICROLIB | ||
|  | 
 | ||
|  |                 EXPORT  __heap_base | ||
|  |                 EXPORT  __heap_limit | ||
|  | 
 | ||
|  |                 ELSE | ||
|  | ; User Initial Stack & Heap
 | ||
|  |                 AREA    |.text|, CODE, READONLY | ||
|  | 
 | ||
|  |                 IMPORT  __use_two_region_memory | ||
|  |                 EXPORT  __user_initial_stackheap | ||
|  | __user_initial_stackheap | ||
|  | 
 | ||
|  |                 LDR     R0, =  Heap_Mem | ||
|  |                 LDR     R1, = (Stack_Mem + IRQ_Stack_Size) | ||
|  |                 LDR     R2, = (Heap_Mem +      Heap_Size) | ||
|  |                 LDR     R3, = Stack_Mem | ||
|  |                 BX      LR | ||
|  |                 ENDIF | ||
|  | 
 | ||
|  |                 END |