9846c062b3
Only tested in an emulator (mGBA). Almost nothing is supported, but drawing to the screen works.
33 строки
1,2 КиБ
ArmAsm
33 строки
1,2 КиБ
ArmAsm
.section .init
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.global _start
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.align
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.arm
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_start:
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b start_vector
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.fill 156,1,0 // Nintendo Logo Character Data (8000004h)
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.fill 16,1,0 // Game Title
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.byte 0x30,0x31 // Maker Code (80000B0h)
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.byte 0x96 // Fixed Value (80000B2h)
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.byte 0x00 // Main Unit Code (80000B3h)
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.byte 0x00 // Device Type (80000B4h)
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.fill 7,1,0 // unused
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.byte 0x00 // Software Version No (80000BCh)
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.byte 0xf0 // Complement Check (80000BDh)
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.byte 0x00,0x00 // Checksum (80000BEh)
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start_vector:
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mov r0, #0x4000000 // REG_BASE
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str r0, [r0, #0x208]
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mov r0, #0x12 // Switch to IRQ Mode
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msr cpsr, r0
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ldr sp, =__sp_irq // Set IRQ stack
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mov r0, #0x1f // Switch to System Mode
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msr cpsr, r0
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ldr sp, =__sp_usr // Set user stack
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// Jump to user code (switching to Thumb mode)
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ldr r3, =main
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bx r3
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