linux VS M1s_BL808_example

The "IRQ router" is handled as a nested interrupt controller in linux. There are some memory mapped registers where we can mask/unmask/clear which interrupts we want to route to D0 from M0. Once one of these unmasked interrupts gets triggered, D0 will get `WL_ALL_IRQn`. And then you have to go look at those memory mapped registers to figure out which M0 interrupt got triggered. Look for function ` GLB_DSP_Get_MCU_IntStatus` and siblings. This functionality is completely undocumented and https://github.com/smaeul figured out how it works. Linux driver is here(https://github.com/openbouffalo/linux/blob/bl808/all/drivers/irqchip/irq-bflb-mcu.c)

If you want to get into other aspects - the bl808 from bouffalo labs is a Triple core ASP (not SMP!) CPU with 64MB of ram (!) for $8. It can run Linux and but still needs a lot of drivers written, from areas like clocks through to SPI/I2C etc. https://github.com/openbouffalo/linux

In general I would recommend looking into the example sources at https://github.com/sipeed/M1s_BL808_example/

The audio may or may not work, and looking at the M1s example code at https://github.com/sipeed/M1s_BL808_example it looks like they are just working in the C906 core (D0 - the 64 bit core), and with similarly limited functionality.

https://github.com/sipeed/M1s_BL808_example here.