Apache #NuttX RTOS on @PINE64 Star64 #JH7110 #RISCV SBC has a problem with Serial I/O and the Platform-Level Interrupt Controller (PLIC) ... Here's how we fixed it

Article: https://lupyuen.codeberg.page/articles/plic

#NuttX Apps on Star64 #JH7110 won't produce any Console Output ... Let's find out why

Article: https://lupyuen.codeberg.page/articles/plic.html#no-console-output-from-nuttx-apps

Serial Output in Apache #NuttX RTOS works like this

Article: https://lupyuen.codeberg.page/articles/plic.html#serial-output-in-nuttx-qemu

Apache #NuttX RTOS handles UART Interrupts for Serial Input

Article: https://lupyuen.codeberg.page/articles/plic.html#serial-input-in-nuttx-qemu

UART is not ready to Transmit on Apache #NuttX RTOS for Star64 #JH7110 ... Let's find out why

Article: https://lupyuen.codeberg.page/articles/plic.html#star64-vs-qemu-serial-io

#NuttX on Star64 #JH7110 won't trigger UART Interrupts ... Let's check the Interrupt Number

Article: https://lupyuen.codeberg.page/articles/plic.html#jh7110-uart-interrupt

Inside #JH7110 is the #RISCV Platform-Level Interrupt Controller (PLIC) ... That handles Interrupts triggered by Peripherals

Article: https://lupyuen.codeberg.page/articles/plic.html#platform-level-interrupt-controller

Each #RISCV Core in #JH7110 can be programmed individually to receive Interrupts ... In Machine or Supervisor Modes

Article: https://lupyuen.codeberg.page/articles/plic.html#memory-map

Here's how we init the #RISCV PLIC Interrupt Controller with Apache #NuttX RTOS

Article: https://lupyuen.codeberg.page/articles/plic.html#initialise-interrupts

How we Claim and Complete #RISCV Interrupts ... With the PLIC Interrupt Controller

Article: https://lupyuen.codeberg.page/articles/plic.html#claim-and-complete-interrupts

Apache #NuttX RTOS runs in Supervisor Mode ... So we delegate #RISCV Interrupts from Machine Mode to Supervisor Mode

Article: https://lupyuen.codeberg.page/articles/plic.html#delegate-machine-mode-interrupts-to-supervisor-mode

Star64 #JH7110 triggers too many UART Interrupts on Apache #NuttX RTOS ... Let's find out why

Article: https://lupyuen.codeberg.page/articles/plic.html#spurious-uart-interrupts