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/*---------------------------------------------------------------------------------
$Id$
Copyright (C) 2005
Dave Murphy (WinterMute)
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any
damages arising from the use of this software.
Permission is granted to anyone to use this software for any
purpose, including commercial applications, and to alter it and
redistribute it freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you
must not claim that you wrote the original software. If you use
this software in a product, an acknowledgment in the product
documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and
must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source
distribution.
---------------------------------------------------------------------------------*/
#ifdef ARM7
.text
#endif
#ifdef ARM9
.section .bsp_fast_text,"ax",%progbits
#endif
.extern irqTable
.code 32
.global IntrMain
@---------------------------------------------------------------------------------
IntrMain:
@---------------------------------------------------------------------------------
mov r3, #0x4000000 @ REG_BASE
ldr r1, [r3, #0x208] @ r1 = IME
str r3, [r3, #0x208] @ disable IME
mrs r0, spsr
stmfd sp!, {r0-r1,r3,lr} @ {spsr, IME, REG_BASE, lr_irq}
ldr r1, [r3,#0x210] @ REG_IE
ldr r2, [r3,#0x214] @ REG_IF
and r1,r1,r2
ldr r0,=__irq_flags @ defined by linker script
ldr r2,[r0]
orr r2,r2,r1
str r2,[r0]
ldr r2,=irqTable
@---------------------------------------------------------------------------------
findIRQ:
@---------------------------------------------------------------------------------
ldr r0, [r2, #4]
cmp r0,#0
beq no_handler
ands r0, r0, r1
bne jump_intr
add r2, r2, #8
b findIRQ
@---------------------------------------------------------------------------------
no_handler:
@---------------------------------------------------------------------------------
str r1, [r3, #0x0214] @ IF Clear
ldmfd sp!, {r0-r1,r3,lr} @ {spsr, IME, REG_BASE, lr_irq}
str r1, [r3, #0x208] @ restore REG_IME
mov pc,lr
@---------------------------------------------------------------------------------
jump_intr:
@---------------------------------------------------------------------------------
ldr r1, [r2] @ user IRQ handler address
cmp r1, #0
bne got_handler
mov r1, r0
b no_handler
@---------------------------------------------------------------------------------
got_handler:
@---------------------------------------------------------------------------------
mrs r2, cpsr
bic r2, r2, #0xdf @ \__
orr r2, r2, #0x1f @ / --> Enable IRQ & FIQ. Set CPU mode to System.
msr cpsr,r2
str r0, [r3, #0x0214] @ IF Clear
push {lr}
adr lr, IntrRet
bx r1
@---------------------------------------------------------------------------------
IntrRet:
@---------------------------------------------------------------------------------
mov r3, #0x4000000 @ REG_BASE
str r3, [r3, #0x208] @ disable IME
pop {lr}
mrs r3, cpsr
bic r3, r3, #0xdf @ \__
orr r3, r3, #0x92 @ / --> Disable IRQ. Enable FIQ. Set CPU mode to IRQ.
msr cpsr, r3
ldmfd sp!, {r0-r1,r3,lr} @ {spsr, IME, REG_BASE, lr_irq}
msr spsr, r0 @ restore spsr
str r1, [r3, #0x208] @ restore REG_IME
mov pc,lr
.pool
.end
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