24 lines
785 B
Zig
24 lines
785 B
Zig
const Bus = @import("../../Bus.zig");
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const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
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const InstrFn = @import("../../cpu.zig").arm.InstrFn;
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pub fn armSoftwareInterrupt() InstrFn {
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return struct {
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fn inner(cpu: *Arm7tdmi, _: *Bus, _: u32) void {
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// Copy Values from Current Mode
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const ret_addr = cpu.r[15] - 4;
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const cpsr = cpu.cpsr.raw;
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// Switch Mode
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cpu.changeMode(.Supervisor);
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cpu.cpsr.t.write(false); // Force ARM Mode
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cpu.cpsr.i.write(true); // Disable normal interrupts
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cpu.r[14] = ret_addr; // Resume Execution
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cpu.spsr.raw = cpsr; // Previous mode CPSR
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cpu.r[15] = 0x0000_0008;
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cpu.pipe.reload(cpu);
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}
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}.inner;
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}
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