mirror of
https://gitlab.com/freepascal.org/fpc/source.git
synced 2025-04-16 08:19:34 +02:00
94 lines
2.8 KiB
ActionScript
94 lines
2.8 KiB
ActionScript
@---------------------------------------------------------------------------------
|
|
.section ".init"
|
|
.global _start
|
|
@---------------------------------------------------------------------------------
|
|
.align 4
|
|
.arm
|
|
@---------------------------------------------------------------------------------
|
|
_start:
|
|
@---------------------------------------------------------------------------------
|
|
mov r0, #0x04000000 @ IME = 0;
|
|
str r0, [r0, #0x208]
|
|
|
|
mov r0, #0x12 @ Switch to IRQ Mode
|
|
msr cpsr, r0
|
|
ldr sp, =__sp_irq @ Set IRQ stack
|
|
|
|
mov r0, #0x13 @ Switch to SVC Mode
|
|
msr cpsr, r0
|
|
ldr sp, =__sp_svc @ Set SVC stack
|
|
|
|
mov r0, #0x1F @ Switch to System Mode
|
|
msr cpsr, r0
|
|
ldr sp, =__sp_usr @ Set user stack
|
|
|
|
ldr r0, =__bss_start @ Clear BSS section to 0x00
|
|
ldr r1, =__bss_end
|
|
sub r1, r1, r0
|
|
bl ClearMem
|
|
|
|
ldr r3, =__libc_init_array @ global constructors
|
|
bl _call_via_r3
|
|
|
|
mov r0, #0 @ int argc
|
|
mov r1, #0 @ char *argv[]
|
|
ldr r3, =main
|
|
bl _call_via_r3 @ jump to user code
|
|
|
|
@ If the user ever returns, return to flash cartridge
|
|
mov r0, #0x08000000
|
|
bx r0
|
|
|
|
@---------------------------------------------------------------------------------
|
|
@ Clear memory to 0x00 if length != 0
|
|
@ r0 = Start Address
|
|
@ r1 = Length
|
|
@---------------------------------------------------------------------------------
|
|
ClearMem:
|
|
@---------------------------------------------------------------------------------
|
|
mov r2, #3 @ Round down to nearest word boundary
|
|
add r1, r1, r2 @ Shouldn't be needed
|
|
bics r1, r1, r2 @ Clear 2 LSB (and set Z)
|
|
bxeq lr @ Quit if copy size is 0
|
|
|
|
mov r2, #0
|
|
ClrLoop:
|
|
stmia r0!, {r2}
|
|
subs r1, r1, #4
|
|
bne ClrLoop
|
|
bx lr
|
|
|
|
@---------------------------------------------------------------------------------
|
|
@ Copy memory if length != 0
|
|
@ r1 = Source Address
|
|
@ r2 = Dest Address
|
|
@ r4 = Dest Address + Length
|
|
@---------------------------------------------------------------------------------
|
|
CopyMemCheck:
|
|
@---------------------------------------------------------------------------------
|
|
sub r3, r4, r2 @ Is there any data to copy?
|
|
@---------------------------------------------------------------------------------
|
|
@ Copy memory
|
|
@ r1 = Source Address
|
|
@ r2 = Dest Address
|
|
@ r3 = Length
|
|
@---------------------------------------------------------------------------------
|
|
CopyMem:
|
|
@---------------------------------------------------------------------------------
|
|
mov r0, #3 @ These commands are used in cases where
|
|
add r3, r3, r0 @ the length is not a multiple of 4,
|
|
bics r3, r3, r0 @ even though it should be.
|
|
bxeq lr @ Length is zero, so exit
|
|
CIDLoop:
|
|
ldmia r1!, {r0}
|
|
stmia r2!, {r0}
|
|
subs r3, r3, #4
|
|
bne CIDLoop
|
|
bx lr
|
|
|
|
@---------------------------------------------------------------------------------
|
|
.align
|
|
.pool
|
|
.end
|
|
@---------------------------------------------------------------------------------
|