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handle timer interrupts and clean up kernel a bit

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This commit is contained in:
Connor Olding 2018-09-29 11:42:28 +02:00
parent 2e99cf982a
commit 2a53db6095
5 changed files with 23 additions and 24 deletions
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2
inc/kernel.inc
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@ -7,7 +7,7 @@ constant K_DUMP(0x0400) // we save registers and state here
constant K_REASON(0x0600)
constant K_CAUSE(0x0604)
constant K_STATUS(0x0608)
constant K_IN_ISR(0x060C)
constant K_UNUSED(0x060C)
constant K_EPC(0x0610)
constant K_ERRORPC(0x0614)
constant K_BADVADDR(0x0618)

1
inc/n64_cp0.inc
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@ -44,7 +44,6 @@ constant CP0_STATUS_IM5($2000) // Interrupt Mask 5 (External)
constant CP0_STATUS_IM6($4000) // Interrupt Mask 6 (External)
constant CP0_STATUS_IM7($8000) // Interrupt Mask 7 (External)
constant CP0_STATUS_IM_ALL($FF00) // all interrupt masks
constant CP0_STATUS_IM_WANTED($7F00) // FIXME: just the interrupts we can deal with
// note that these are all masks.
constant CP0_CAUSE_CODE($007C) // actually supposed to be called ExcCode

2
inc/n64_util.inc
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@ -20,7 +20,7 @@ macro SetIntMask() {
sw t0, MI_INTR_MASK(a0)
// careful not to touch unrelated flags here
mfc0 t1, CP0_Status
lli t0, CP0_STATUS_IM_WANTED
lli t0, CP0_STATUS_IM_ALL
or t1, t0
mtc0 t1, CP0_Status
}

2
init.asm
View file

@ -98,7 +98,7 @@
// enable CPU interrupts.
mfc0 t1, CP0_Status
ori t1, CP0_STATUS_IM_WANTED | CP0_STATUS_IE
ori t1, CP0_STATUS_IM_ALL | CP0_STATUS_IE
mtc0 t1, CP0_Status
// enable even more interrupts.

40
kernel.asm
View file

@ -21,7 +21,7 @@ include "init.asm"
// or just DMA in the ISR and our defaults from ROM...
sw r0, K_64DRIVE_MAGIC(gp)
sw r0, K_REASON(gp)
sw r0, K_IN_ISR(gp)
sw r0, K_UNUSED(gp)
sw r0, K_CONSOLE_AVAILABLE(gp)
sw r0, K_HISTORY(gp)
@ -29,7 +29,7 @@ Drive64Init:
lui t9, CI_BASE
lui t2, 0x5544 // "UD" of "UDEV"
lw t1, CI_HW_MAGIC(t9)
ori t2, t2, 0x4556 // "EV" of "UDEV"
ori t2, 0x4556 // "EV" of "UDEV"
beq t1, t2, Drive64Confirmed
nop
@ -78,12 +78,12 @@ evaluate x({x} + 8)
WipeRegisters:
// load up most registers with a dummy value for debugging
lui at, 0xCAFE
ori at, at, 0xBABE
ori at, 0xBABE
dsll at, 16
// attempting to use this as an address should trigger an interrupt
ori at, at, 0xDEAD
ori at, 0xDEAD
dsll at, 16
ori at, at, 0xBEEF
ori at, 0xBEEF
// k0, k1, sp intentionally absent
daddu v0, at, r0
@ -218,12 +218,6 @@ InterruptHandler:
mfc0 k1, CP0_BadVAddr
sw k1, K_BADVADDR(k0)
// prevent recursive interrupts if ISR_Main somehow causes an interrupt
// lw t1, K_IN_ISR(k0)
// bnez t1, ISR_Exit // TODO: reimplement properly
lli t0, 1
sw t0, K_IN_ISR(k0)
// be wary, this is a tiny temporary stack!
ori sp, k0, K_STACK
@ -233,6 +227,15 @@ ISR_Main: // free to modify any GPR from here to ISR_Exit
KWriteString(KS_Handling)
KWriteString(KS_Code)
// handle timer interrupt
lw t0, K_CAUSE(k0)
andi t0, CP0_CAUSE_IP7
beqz t0, ISR_CountDone
nop
KWriteString(KS_Timer)
mtc0 r0, CP0_Compare
ISR_CountDone:
// switch-case on the cause code:
// conveniently, the ExcCode in Cause is already shifted left by 2.
lw t4, K_CAUSE(k0)
@ -277,8 +280,6 @@ if K_DEBUG {
}
ISR_Exit:
sw r0, K_IN_ISR(k0)
lui k0, K_BASE
ld t0, K_DUMP+0x100(k0)
ld t1, K_DUMP+0x108(k0)
@ -369,12 +370,10 @@ K_MI_Loop:
K_MI_SP:
KWriteString(KS_MI_SP)
lli t0, SP_RSPSIGNAL_CLR | SP_INT_CLR
lli t0, SP_INT_CLR
lui a1, SP_BASE
sw t0, SP_STATUS(a1)
// then check andi t1, SP_YIELDED | SP_TASKDONE ?
lw t0, K_HISTORY(k0)
ori t0, MI_INTR_SP
sw t0, K_HISTORY(k0)
@ -396,9 +395,8 @@ K_MI_SI:
K_MI_AI:
KWriteString(KS_MI_AI)
lli t0, 0x01
lui a1, AI_BASE
sw t0, AI_STATUS(a1)
sw r0, AI_STATUS(a1)
lw t0, K_HISTORY(k0)
ori t0, MI_INTR_AI
@ -410,7 +408,8 @@ K_MI_VI:
KWriteString(KS_MI_VI)
lui a1, VI_BASE
sw r0, VI_V_CURRENT_LINE(a1)
lw t0, VI_V_CURRENT_LINE(a1)
sw t0, VI_V_CURRENT_LINE(a1)
lw t0, K_HISTORY(k0)
ori t0, MI_INTR_VI
@ -434,7 +433,7 @@ K_MI_PI:
K_MI_DP:
KWriteString(KS_MI_DP)
lli t0, 0x800
lli t0, 0x0800
lui a1, MI_BASE
sw t0, MI_INIT_MODE(a1)
@ -528,6 +527,7 @@ KSL(KS_Code29, "RESERVED 29")
KSL(KS_Code30, "RESERVED 30")
KSL(KS_Code31, "RESERVED 31")
KSL(KS_Timer, " * Timer Interrupt")
KSL(KS_MI_SP, " * Signal Processor Interrupt")
KSL(KS_MI_SI, " * Serial Interface Interrupt")
KSL(KS_MI_AI, " * Audio Interface Interrupt")