Interrupts #
Interrupt priority is 0-0xF. A priority of 0xF means that the interrupt is disabled.
Private Interrupts #
Each CPU core has 32 software interrupts that are private and belong to that core. These interrupts are numbers 0-0x1F for each core. The hardware interrupts are not core-specific and start at interrupt ID 0x20.
| IRQ | Listener | Description |
|---|---|---|
| 0 | MPCore software-interrupt. Used by Kernel11 to sync cores in crt0. | |
| 0x1-0x3 | MPCore software-interrupt. Used by Boot11 and Kernel11 to kickstart Core1/2/3, and by Kernel11 to sync cores in crt0. | |
| 0x4 | Kernel | MPCore software-interrupt. Used to manage the performance counter. Also used by Kernel11 during crt0 to sync up. |
| 0x5 | Kernel | MPCore software-interrupt. Does apparently nothing. |
| 0x6 | Kernel | MPCore software-interrupt. Extensively used by KernelSetState (and contains most of the actual code of the latter). |
| 0x7 | Kernel | MPCore software-interrupt. See KCacheMaintenanceInterruptEvent |
| 0x8 | Kernel | MPCore software-interrupt. Used for scheduling. |
| 0x9 | Kernel | MPCore software-interrupt. Used when handling exceptions that require termination of a thread or a process, and in some cases by svcSetDebugThreadContext, to store VFP registers in the thread’s register storage. |
| 0xA | Kernel | TLB operations interrupt, see KTLBOperationsInterruptEvent |
| 0xB-0xE | MPCore software-interrupt. Not configured. | |
| 0xF | dmnt/debugger | MPCore software-interrupt. Used to abstract FIQ (debug). This interrupt is never sent to core2 nor core3 on N3DS. |
| 0x1D | Kernel | MPCore timer. |
| 0x1E | Kernel | MPCore watchdog - set when the watchdog counter reaches 0 in timer mode, causes interrupt 30 to set as pending. Only set on core 1 as core 1’s timer is used for everything. |
Hardware Interrupts #
There are 0x60 hardware interrupts starting at 0x20 and continuing up to 0x7F. These are not private and are accessible from any core.
| IRQ | Listener | Description |
|---|---|---|
| 0x24 | ? | SPI bus 2 interrupt status update |
| 0x28 | gsp, TwlBg | PSC0 |
| 0x29 | gsp, TwlBg | PSC1 |
| 0x2A | gsp, TwlBg | PDC0 (Top screen VBlank0, HBlank0) |
| 0x2B | gsp, TwlBg | PDC1 (Bottom screen VBlank1, HBlank1) |
| 0x2C | gsp, TwlBg | PPF |
| 0x2D | gsp, TwlBg | P3D |
| 0x30-0x38 | Kernel | Old CDMA Event 0..8 (9 separate IRQ lines) |
| 0x39 | Kernel | Old CDMA Faulting (eg. CCR=0, or event>15) |
| 0x3A | Kernel | New CDMA Event 0..31 (shared IRQ line) |
| 0x3B | Kernel | New CDMA Faulting (eg. CCR=0) |
| 0x40 | nwm | WIFI SDIO Controller @ 0x10122000 |
| 0x41 | nwm | WIFI SDIO Controller IRQ pin @ 0x10122000 |
| 0x42 | nwm_dev? | Debug WIFI SDIO Controller @ 0x10100000 ? |
| 0x43 | nwm_dev? | Debug WIFI SDIO Controller @ 0x10100000 ? |
| 0x44 | ? | NTRCARD (maybe?) |
| 0x45 | mvd (New3DS) | L2B_0 (First RGB-to-RGBA Converter) |
| 0x46 | mvd (New3DS) | L2B_1 (Second RGB-to-RGBA Converter) |
| 0x48 | camera | Camera Bus 0 (DSi cameras) |
| 0x49 | camera | Camera Bus 1 (left-eye) |
| 0x4A | dsp | General interrupt from DSP, including semaphore and command/reply registers status change |
| 0x4B | camera | Y2R Conversion Finished |
| 0x4C | TwlBg | LGYFB_0 Legacy GBA/NDS Video |
| 0x4D | TwlBg | LGYFB_1 Legacy GBA/NDS Video |
| 0x4E | mvd (New3DS) | Y2R2 End Event |
| 0x4F | mvd (New3DS) | MVD general interrupt? |
| 0x50 | pxi, TwlBg | Sync (bit 29 from Arm9’s PXI_SYNC) |
| 0x51 | pxi, TwlBg | Sync 2 (bit 30 from Arm9’s PXI_SYNC) |
| 0x52 | pxi, TwlBg | Send Fifo Empty |
| 0x53 | pxi, TwlBg | Receive Fifo Not Empty |
| 0x54 | i2c, TwlBg | I2C Bus0 work done |
| 0x55 | i2c, TwlBg | I2C Bus1 work done |
| 0x56 | spi, TwlBg | SPI bus 3 interrupt status update |
| 0x57 | spi, TwlBg | SPI bus 1 interrupt status update |
| 0x58 | Kernel | PDN (wake event or SoC mode changed) |
| 0x59 | TwlBg | PDN Legacy Sleep |
| 0x5A | mic | General microphone interrupt (?) |
| 0x5B | - | HID_PAD_CNT |
| 0x5C | i2c, TwlBg | I2C Bus2 work done |
| 0x5F | mp | DS WiFi registers |
| 0x60 | gpio, TwlBg | Shell opened (GPIO1_2 falling edge) |
| 0x62 | gpio, TwlBg | Shell closed (GPIO1_2 rising edge) |
| 0x63 | gpio, TwlBg | Touch Screen pressed (GPIO1_1 falling edge) |
| 0x64 | gpio, TwlBg | Headphones inserted (GPIO2_0) |
| 0x66 | gpio, TwlBg | TWL depop circuit (GPIO2_1) |
| 0x68 | gpio, TwlBg | C-stick interrupt (GPIO3_0) |
| 0x69 | gpio, TwlBg | IrDA interrupt (active-low) (GPIO3_1) |
| 0x6A | gpio, TwlBg | Gyro interrupt (GPIO3_2) |
| 0x6B | gpio, TwlBg | C-stick “stop” (output) (GPIO3_3) |
| 0x6C | gpio, TwlBg | IrDA TX-RC (output) (GPIO3_4) |
| 0x6D | gpio, TwlBg | IrDA RXD (GPIO3_5) |
| 0x6E | gpio, TwlBg | NFC output1 (?) (GPIO3_6) |
| 0x6F | gpio, TwlBg | NFC output2 (?) (GPIO3_7) |
| 0x70 | gpio, TwlBg | Headphones button/half-inserted (active-low) (GPIO3_8) |
| 0x71 | gpio, TwlBg | MCU interrupt (GPIO3_9) |
| 0x72 | gpio, TwlBg | NFC interrupt (?) (GPIO3_10) |
| 0x73 | TwlBg | QTM output (?) (GPIO3_11) |
| 0x74 | ? | Gamecard related |
| 0x75 | ? | Gamecard inserted |
| 0x76 | - | L2C |
| 0x78 to 0x7B | Kernel | Core 0-3 Performance monitor counter (any) overflow |
| 0x7A to 0x82 (PDN_MPCORE_CFG bit2 set) or 0x7C to 0x84 (bit2 clear) | Kernel | Other PMU interrupts (line may not exist at all) |
(interrupts from 0x80 and up can’t be mapped in available builds of the kernel)
There are 2 tables in the Arm11 kernel: the first has 32 * 2(or 32 * 4) 8-byte entries. This table is for the private interrupts that belong to each core. The data for each interrupt can be found by doing table_base + (core_num * 0x100) + (intr_num * 8). The second table is for public hardware interrupts and the data for each interrupt can be retrieved by doing table_base + (intr_num * 8).
The Arm11 kernel configures interrupts the following way (it seems the GPIO IRQ layout doesn’t match released 3DS models):
Interrupts 0x00 to 0x1F: edge-triggered, N-N
Interrupt 0x20: level-sensitive, 1-N
Interrupt 0x21: level-sensitive, 1-N
Interrupt 0x22: level-sensitive, 1-N
Interrupt 0x23: level-sensitive, 1-N
Interrupt 0x24: edge-triggered, 1-N
Interrupt 0x25: level-sensitive, 1-N
Interrupt 0x28: level-sensitive, 1-N
Interrupt 0x29: level-sensitive, 1-N
Interrupt 0x2a: level-sensitive, 1-N
Interrupt 0x2b: level-sensitive, 1-N
Interrupt 0x2c: level-sensitive, 1-N
Interrupt 0x2d: level-sensitive, 1-N
Interrupt 0x30: level-sensitive, 1-N
Interrupt 0x31: level-sensitive, 1-N
Interrupt 0x32: level-sensitive, 1-N
Interrupt 0x33: level-sensitive, 1-N
Interrupt 0x34: level-sensitive, 1-N
Interrupt 0x35: level-sensitive, 1-N
Interrupt 0x36: level-sensitive, 1-N
Interrupt 0x37: level-sensitive, 1-N
Interrupt 0x38: level-sensitive, 1-N
Interrupt 0x39: level-sensitive, 1-N
Interrupt 0x3a: level-sensitive, 1-N
Interrupt 0x3b: level-sensitive, 1-N
Interrupt 0x40: edge-triggered, 1-N
Interrupt 0x41: edge-triggered, 1-N
Interrupt 0x42: edge-triggered, 1-N
Interrupt 0x43: edge-triggered, 1-N
Interrupt 0x44: edge-triggered, 1-N
Interrupt 0x45: edge-triggered, 1-N
Interrupt 0x46: edge-triggered, 1-N
Interrupt 0x48: edge-triggered, 1-N
Interrupt 0x49: edge-triggered, 1-N
Interrupt 0x4a: edge-triggered, 1-N
Interrupt 0x4b: edge-triggered, 1-N
Interrupt 0x4c: edge-triggered, 1-N
Interrupt 0x4d: edge-triggered, 1-N
Interrupt 0x4e: edge-triggered, 1-N
Interrupt 0x4f: level-sensitive, 1-N
Interrupt 0x50: edge-triggered, 1-N
Interrupt 0x51: edge-triggered, 1-N
Interrupt 0x52: edge-triggered, 1-N
Interrupt 0x53: edge-triggered, 1-N
Interrupt 0x54: edge-triggered, 1-N
Interrupt 0x55: edge-triggered, 1-N
Interrupt 0x56: edge-triggered, 1-N
Interrupt 0x57: edge-triggered, 1-N
Interrupt 0x58: level-sensitive, 1-N
Interrupt 0x59: edge-triggered, 1-N
Interrupt 0x5a: edge-triggered, 1-N
Interrupt 0x5b: edge-triggered, 1-N
Interrupt 0x5f: edge-triggered, 1-N
Interrupt 0x60: edge-triggered, 1-N
Interrupt 0x61: edge-triggered, 1-N
Interrupt 0x64: edge-triggered, 1-N
Interrupt 0x65: edge-triggered, 1-N
Interrupt 0x66: edge-triggered, 1-N
Interrupt 0x68: edge-triggered, 1-N
Interrupt 0x69: edge-triggered, 1-N
Interrupt 0x6a: edge-triggered, 1-N
Interrupt 0x6b: edge-triggered, 1-N
Interrupt 0x6c: edge-triggered, 1-N
Interrupt 0x6d: edge-triggered, 1-N
Interrupt 0x6e: edge-triggered, 1-N
Interrupt 0x6f: edge-triggered, 1-N
Interrupt 0x70: edge-triggered, 1-N
Interrupt 0x71: edge-triggered, 1-N
Interrupt 0x72: edge-triggered, 1-N
Interrupt 0x73: edge-triggered, 1-N
Interrupt 0x74: edge-triggered, 1-N
Interrupt 0x75: edge-triggered, 1-N
Interrupt 0x76: level-sensitive, 1-N
Interrupt 0x77: level-sensitive, 1-N
Interrupt 0x78: edge-triggered, 1-N
Interrupt 0x79: level-sensitive, 1-N
Interrupt 0x7a: level-sensitive, 1-N
Interrupt 0x7b: level-sensitive, 1-N
Interrupt 0x7c: level-sensitive, 1-N
Interrupt 0x7d: level-sensitive, 1-N
InterruptData #
| Offset | Type | Description |
|---|---|---|
| 0x0 | KBaseInterruptEvent * | Pointer to the KBaseInterruptEvent object for this interrupt |
| 0x4 | u8 | Interrupt will be disabled by the IRQ handler as soon as it is acknowledged. Ignored for FIQ: the FIQ handler always sets bit2 of PDN_FIQ_CNT |
| 0x5 | u8 | Interrupt is disabled |
| 0x6 | u8 | Interrupt priority |
| 0x7 | u8 | Unused, alignment |
Interrupt Table (New3DS) #
(0xFFF318F4 in 10.3)
| Offset | Type | Description |
|---|---|---|
| 0x0 | InterruptData[224] | Data for all hardware and software interrupts |
| 0x700 | KObjectMutex | Mutex |