📄 startup.s
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/***********************************************************************/
/* This file is part of the uVision/ARM development tools */
/* Copyright KEIL ELEKTRONIK GmbH 2002-2004 */
/***********************************************************************/
/* */
/* STARTUP.S: Startup file for Philips LPC2000 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:
// Phase Locked Loop (PLL) definitions
PLL_BASE EQU 0xE01FC080 /* PLL Base Address */
PLLCON_OFS EQU 0x00 /* PLL Control Offset*/
PLLCFG_OFS EQU 0x04 /* PLL Configuration Offset */
PLLSTAT_OFS EQU 0x08 /* PLL Status Offset */
PLLFEED_OFS EQU 0x0C /* PLL Feed Offset */
PLLCON_PLLE EQU (1<<0) /* PLL Enable */
PLLCON_PLLC EQU (1<<1) /* PLL Connect */
PLLCFG_MSEL EQU (0x1F<<0) /* PLL Multiplier */
PLLCFG_PSEL EQU (0x03<<5) /* PLL Divider */
PLLSTAT_PLOCK EQU (1<<10) /* PLL Lock Status */
/*
// <e> PLL Setup
// <i> Phase Locked Loop
// <o1.0..4> MSEL: PLL Multiplier Selection
// <1-32><#-1>
// <i> M Value
// <o1.5..6> PSEL: PLL Divider Selection
// <0=> 1 <1=> 2 <2=> 4 <3=> 8
// <i> P Value
// </e>
*/
PLL_SETUP EQU 1
PLLCFG_Val EQU 0x00000024
// Memory Accelerator Module (MAM) definitions
MAM_BASE EQU 0xE01FC000 /* MAM Base Address */
MAMCR_OFS EQU 0x00 /* MAM Control Offset*/
MAMTIM_OFS EQU 0x04 /* MAM Timing Offset */
/*
// <e> MAM Setup
// <i> Memory Accelerator Module
// <o1.0..1> MAM Control
// <0=> Disabled
// <1=> Partially Enabled
// <2=> Fully Enabled
// <i> Mode
// <o2.0..2> MAM Timing
// <0=> Reserved <1=> 1 <2=> 2 <3=> 3
// <4=> 4 <5=> 5 <6=> 6 <7=> 7
// <i> Fetch Cycles
// </e>
*/
MAM_SETUP EQU 1
MAMCR_Val EQU 0x00000002
MAMTIM_Val EQU 0x00000004
// Starupt Code must be linked first at Address at which it expects to run.
$IF (RAM_INTVEC)
CODE_BASE EQU 0x40000000
$ELSE
CODE_BASE EQU 0x00000000
$ENDIF
AREA STARTUPCODE, CODE, AT CODE_BASE // READONLY, ALIGN=4
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)
// 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,[PC, #-0x0FF0] /* Vector from VicVectAddr */
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:
IF (PLL_SETUP != 0)
LDR R0, =PLL_BASE
MOV R1, #0xAA
MOV R2, #0x55
// Configure and Enable PLL
MOV R3, #PLLCFG_Val
STR R3, [R0, #PLLCFG_OFS]
MOV R3, #PLLCON_PLLE
STR R3, [R0, #PLLCON_OFS]
STR R1, [R0, #PLLFEED_OFS]
STR R2, [R0, #PLLFEED_OFS]
// Wait until PLL Locked
PLL_Loop: LDR R3, [R0, #PLLSTAT_OFS]
ANDS R3, R3, #PLLSTAT_PLOCK
BEQ PLL_Loop
// Switch to PLL Clock
MOV R3, #(PLLCON_PLLE | PLLCON_PLLC)
STR R3, [R0, #PLLCON_OFS]
STR R1, [R0, #PLLFEED_OFS]
STR R2, [R0, #PLLFEED_OFS]
ENDIF
IF (MAM_SETUP != 0)
LDR R0, =MAM_BASE
MOV R1, #MAMTIM_Val
STR R1, [R0, #MAMTIM_OFS]
MOV R1, #MAMCR_Val
STR R1, [R0, #MAMCR_OFS]
ENDIF
// Memory Mapping (when Interrupt Vectors are in RAM)
MEMMAP EQU 0xE01FC040 /* Memory Mapping Control */
$IF (RAM_INTVEC)
LDR R0, =MEMMAP
MOV R1, #2
STR R1, [R0]
$ENDIF
// 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
exit: B exit?T
ENDP
END
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