; Memory Mapping (when Interrupt Vectors are in RAM)
MEMMAP EQU 0xE01FC040 ; Memory Mapping Control
IF :DEF:REMAP
LDR R0, =MEMMAP
IF :DEF:EXTMEM_MODE
MOV R1, #3
ELIF :DEF:RAM_MODE
MOV R1, #2
ELSE
MOV R1, #1
ENDIF
STR R1, [R0]
ENDIF
; Initialise Interrupt System
; ...
; 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
MOV SP, R0
SUB SL, SP, #USR_Stack_Size
ENDIF
; Enter the C code
IMPORT __main
LDR R0, =__main
BX R0