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Changes
AGB boot notes
The 3DS utilizes an onboard ARM7 core to handle TWL_FIRM and AGB_FIRM's ARM7 requirements. This is due to the fact that much of the hardware used by both ARM7 and ARM9 is (evidently) not physically hooked up to ARM11. Thus, ARM11 cannot simply emulate ARM7.
The 3DS utilizes an onboard ARM7 core to handle TWL_FIRM and AGB_FIRM's ARM7 requirements. This is due to the fact that much of the hardware used by both ARM7 and ARM9 is (evidently) not physically hooked up to ARM11. Thus, ARM11 cannot simply emulate ARM7.
ARM7 has the AGB BIOS implemented in hardware. The BIOS is completely identical to the original AGB BIOS. This, combined with the onboard 2D graphics engine, makes for almost perfect Gameboy Advance "emulation."
ARM7 has the AGB BIOS implemented in hardware. The BIOS is completely identical to the original AGB BIOS. The system is booted silently by calling SWI 0x1 (RegisterRamReset), followed by jumping to the code that does SWI 0x0 (SoftReset) to finish booting. The boot splash is still in BIOS, however, and can be seen by calling (or replacing one of the previous interrupts with) SWI 0x26 (HardReset).
= Registers =
= Registers =
ARM9 interfaces with the ARM7 through the following registers:
ARM9 interfaces with the ARM7 through the following registers: