Lup Yuen Lee 李立源 @lupyuen@qoto.org

#NuttX Kernel Mode executes NuttX Apps in unprivileged User Mode

Article: https://lupyuen.codeberg.page/articles/privilege.html#nuttx-flat-mode-becomes-kernel-mode

Switching #NuttX from #RISCV Machine Mode to Supervisor Mode

Article: https://lupyuen.codeberg.page/articles/privilege.html#risc-v-machine-mode-becomes-supervisor-mode

#RISCV Star64 #JH7110 SBC now officially supported by Apache #NuttX RTOS! 🎉

Source: https://github.com/apache/nuttx/pull/10094

Testing #RISCV Star64 #JH7110 SBC with Apache #NuttX RTOS ... Thanks to TFTP 👍

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

We change #RISCV "mstatus" to "sstatus" in Apache #NuttX RTOS ... Because it runs in Supervisor Mode on Star64 #JH7110

Article: https://lupyuen.codeberg.page/articles/privilege.html#risc-v-privilege-levels

#RISCV "mstatus" Register won't work in #NuttX RTOS because we're running in Supervisor Mode ... Let's fix it for #JH7110

Article: https://lupyuen.codeberg.page/articles/privilege.html#critical-section-doesnt-return

Booting #RISCV Star64 #JH7110 SBC ... With Apache #NuttX RTOS 🎉

Source: https://github.com/lupyuen/nuttx-star64#nuttx-boots-ok-on-star64-jh7110

Apache #NuttX RTOS finally boots OK on #RISCV Star64 #JH7110 SBC 🎉 ... Right after we fixed the Spurious (and Furious) UART Interrupts 👍

Source: https://github.com/lupyuen/nuttx-star64#nuttx-boots-ok-on-star64-jh7110

Let's find out why #NuttX on Star64 #JH7110 gets stuck ... When we enter a Critical Section

Article: https://lupyuen.codeberg.page/articles/privilege.html#critical-section-doesnt-return

Creating a Bootable MicroSD for #NuttX on Star64 #JH7110 ... With a Flat Image Tree (FIT)

Source: https://github.com/lupyuen/nuttx-star64#bootable-microsd-for-nuttx

Here's the answer: UART Registers on Star64 #JH7110 are spaced differently from QEMU!

Article: https://lupyuen.codeberg.page/articles/privilege.html#uart-registers-are-spaced-differently

Guess why this UART code loops forever on Star64 #JH7110 #RISCV SBC

Article: https://lupyuen.codeberg.page/articles/privilege.html#wait-forever-in-uart-transmit

Apache #NuttX RTOS supports 64-bit #RISCV StarFive #JH7110 SoC! 🎉 ... Now merging #Pine64 Star64 SBC into NuttX Mainline 👍

Source: https://github.com/apache/nuttx/pull/10069

Apache #NuttX RTOS now supports Synopsys DesignWare 8250 UART 👍

Source: https://github.com/apache/nuttx/pull/10019

We're porting Apache #NuttX RTOS to @PINE64 Star64 #JH7110 SBC ... Let's talk about the #RISCV Privilege Levels and UART Registers

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

How we fixed the Spurious UART Interrupts on #RISCV Star64 #JH7110 and Apache #NuttX RTOS

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

Here are the #UBoot Commands for Network Boot

Article: https://lupyuen.codeberg.page/articles/tftp.html#appendix-commands-for-u-boot-bootloader

Inside the U-Boot Startup Script for #RISCV Star64 #JH7110 SBC

Article: https://lupyuen.codeberg.page/articles/tftp.html#appendix-boot-script-for-u-boot-bootloader

Fixed the Spurious UART Interrupts for Apache #NuttX RTOS on Star64 #JH7110 🎉 ... Be careful with the UART Line Control Register! 👍

Source: https://www.mail-archive.com/dev@nuttx.apache.org/msg10275.html

Spurious UART Interrupts on Apache #NuttX RTOS for Star64 #JH7110 ... We might have a fix 👍

Source: https://news.ycombinator.com/item?id=36964561