// Main Program Logic. Called by `leds_rust_main`
fn rust_main(_argc: i32, _argv: *const *const u8)  // Args from NuttX Shell
  -> Result<i32, i32> {  // Return a Result Code (int) or Error Code (int)

  // Open the LED Device
  safe_puts("Hello, Rust!!");
  let fd = safe_open("/dev/userleds", O_WRONLY) ?;  // Quit on error

  // Flip LED 1 to On
  safe_ioctl(fd, ULEDIOC_SETALL, 1) ?;  // Quit on error
  unsafe { usleep(500_000); }

  // Flip LED 1 to Off
  safe_ioctl(fd, ULEDIOC_SETALL, 0) ?;  // Quit on error
  unsafe { close(fd); }

  // Return successfully with result 0
  Ok(0)
}

// Comment out these lines for testing on Linux / macOS / Windows
#![no_main]  // For NuttX Only: No Main Function
#![no_std]   // For NuttX Only: Use Rust Core Library (instead of Rust Standard Library)

// Import the NuttX Module
mod nuttx;
use nuttx::*;

## TODO: Install the NuttX Build Prerequisites, skip the RISC-V Toolchain
## https://lupyuen.github.io/articles/nuttx#install-prerequisites

## TODO: Download the xPack Toolchain for RISC-V
## https://lupyuen.github.io/articles/riscv#appendix-xpack-gnu-risc-v-embedded-gcc-toolchain-for-64-bit-risc-v

## Install the Rust Target for QEMU RISC-V 64-bit
rustup target add riscv64gc-unknown-none-elf

## Install QEMU Emulator for RISC-V
sudo apt install qemu-system-riscv64  ## For Linux
brew install qemu  ## For macOS

## Download the Source Code for NuttX Kernel and Apps
git clone https://github.com/apache/nuttx
git clone https://github.com/apache/nuttx-apps apps
cd nuttx

## Configure the NuttX Build: QEMU RISC-V 64-bit with LED Driver and Rust
tools/configure.sh rv-virt:leds64_rust

## Build the NuttX Kernel. Ignore the warning: `nuttx has a LOAD segment with RWX permissions`
make

## Boot the NuttX Kernel in QEMU RISC-V 64-bit
qemu-system-riscv64 \
  -semihosting \
  -M virt,aclint=on \
  -cpu rv64 \
  -bios none \
  -kernel nuttx \
  -nographic

NuttShell (NSH) NuttX-12.6.0-RC1
nsh> leds_rust
Hello, Rust!!
Opening /dev/userleds

Set LED 1 to 1
board_userled: LED 1 set to 1
board_userled: LED 2 set to 0
board_userled: LED 3 set to 0
Sleeping...

Set LED 1 to 0
board_userled: LED 1 set to 0
board_userled: LED 2 set to 0
board_userled: LED 3 set to 0

let fd = safe_open(  // Open the LED Device...
  "/dev/userleds",   // Device Path
  O_WRONLY           // Open for Write-Only
) ?;                 // Quit on error

// Wait a while
unsafe { usleep(500_000); }
...
// Close the LED Device
unsafe { close(fd); }

// Comment out these lines for testing on Linux / macOS / Windows
#![no_main]  // For NuttX Only: No Main Function
#![no_std]   // For NuttX Only: Use Rust Core Library (instead of Rust Standard Library)

$ git clone https://github.com/lupyuen/nuttx-rust-app
$ cd nuttx-rust-app
$ cd app
$ cargo run
Hello, Rust!!
Opening /dev/userleds
ERROR: rust_main() failed with error -1

// `rust_main` accepts the args from NuttX Shell
// And returns a Result Code (int) or Error Code (int)
fn rust_main(_argc: i32, _argv: *const *const u8)
  -> Result<i32, i32> { ... }

// For NuttX: This will be called by NuttX Shell
// For Linux / macOS / Windows: This wil be called by `main`
#[no_mangle]
pub extern "C" fn leds_rust_main(argc: i32, argv: *const *const u8)  // Args from NuttX Shell
  -> i32 {  // Return a Result Code (0) or Error Code (negative)

  // Call the program logic in Rust Main
  let res = rust_main(argc, argv);

  // If Rust Main returns an error, print it.
  // We won't wrap `printf`, because it needs VarArgs.
  if let Err(e) = res {
    unsafe { printf(b"ERROR: rust_main() failed with error %d\n\0" as *const u8, e); }
    e  // Return the Error Code
  } else {
    0  // Or return the Result Code 0
  }
}

// For Linux / macOS / Windows: Define the Main Function
#[cfg(not(target_os = "none"))]
fn main() {
  // Call Rust Main without args
  leds_rust_main(
    0,                 // argc: Zero Args
    core::ptr::null()  // argv: Null Pointer
  );
}

// For NuttX Only: Import the Panic Type
#[cfg(target_os = "none")]
use core::{
  panic::PanicInfo,
  result::Result::{self, Err, Ok},
};

// For NuttX Only: Define the Panic Handler for `no_std`
#[cfg(target_os = "none")]
#[panic_handler]
fn panic(_panic: &PanicInfo<'_>) -> ! {
  loop {}
}

## Configure the NuttX Project
## for QEMU RISC-V 64-bit including Rust
$ tools/configure.sh rv-virt:leds64_rust

## Build the NuttX Project
## Which calls `rustc`
$ make

## Start the QEMU Emulator for 64-bit RISC-V
$ spawn qemu-system-riscv64 \
  -semihosting \
  -M virt,aclint=on \
  -cpu rv64 \
  -bios none \
  -kernel nuttx \
  -nographic

## Run `leds_rust` and verify the output
NuttShell (NSH) NuttX-12.6.0-RC1
nsh> leds_rust
Hello, Rust!!
Opening /dev/userleds

Set LED 1 to 1
board_userled: LED 1 set to 1
board_userled: LED 2 set to 0
board_userled: LED 3 set to 0
Sleeping...

Set LED 1 to 0
board_userled: LED 1 set to 0
board_userled: LED 2 set to 0
board_userled: LED 3 set to 0

## Download the Source Code for NuttX Kernel and Apps
git clone https://github.com/apache/nuttx
git clone https://github.com/apache/nuttx-apps apps
cd nuttx

## Install the Rust Target for QEMU RISC-V 64-bit
rustup target add riscv64gc-unknown-none-elf

## Configure the NuttX Build: QEMU RISC-V 64-bit with LED Driver and Rust
tools/configure.sh rv-virt:leds64_rust

## Build the NuttX Kernel. Ignore the warning: `nuttx has a LOAD segment with RWX permissions`
make

## Install QEMU Emulator for RISC-V
sudo apt install qemu-system-riscv64

## Test NuttX and Rust Blinky with our Expect Script
wget https://raw.githubusercontent.com/lupyuen/nuttx-riscv64/main/qemu-riscv-leds64-rust.exp
chmod +x qemu-riscv-leds64-rust.exp
./qemu-riscv-leds64-rust.exp

#!/usr/bin/expect
## Expect Script for Testing NuttX Rust Blinky with QEMU Emulator

## Wait at most 10 seconds
set timeout 10

## For every 1 character sent, wait 0.01 milliseconds
set send_slow {1 0.01}

## Start the QEMU Emulator for 64-bit RISC-V
spawn qemu-system-riscv64 \
  -semihosting \
  -M virt,aclint=on \
  -cpu rv64 \
  -bios none \
  -kernel nuttx \
  -nographic

## Wait for the prompt and enter `leds_rust`
expect "nsh> "
send -s "leds_rust\r"

## Check the response: LEDs 1, 2 and 3 should be Off
expect "board_userled: LED 1 set to 0"
expect "board_userled: LED 2 set to 0"
expect {
  ## If we see this message, continue normally
  "board_userled: LED 3 set to 0" {}

  ## If timeout, exit with an error
  ## And rerminate the session: Ctrl-A x
  timeout { 
    send "\x01x"
    puts "\n===== Error: Test Failed\n"
    exit 1 
  }
}

## Terminate the session: Ctrl-A x
send "\x01x"
puts "\n===== Test OK\n"
exit 0 

## Start the QEMU Emulator for 32-bit RISC-V
$ spawn qemu-system-riscv32 \
  -semihosting \
  -M virt,aclint=on \
  -cpu rv32 \
  -bios none \
  -kernel nuttx \
  -nographic

## Run `ostest` and verify the output
NuttShell (NSH) NuttX-12.6.0-RC1
nsh> ostest
...
ostest_main: Exiting with status 0

## Download the Source Code for NuttX Kernel and Apps
git clone https://github.com/apache/nuttx
git clone https://github.com/apache/nuttx-apps apps
cd nuttx

## Configure the NuttX Build: QEMU RISC-V 32-bit (Flat Build)
tools/configure.sh rv-virt:nsh

## Build the NuttX Kernel. Ignore the warning: `nuttx has a LOAD segment with RWX permissions`
make

## Install QEMU Emulator for RISC-V (32-bit)
sudo apt install qemu-system-riscv32

## Test NuttX and OSTest with our Expect Script
wget https://raw.githubusercontent.com/lupyuen/nuttx-riscv64/main/qemu-riscv-nsh.exp
chmod +x qemu-riscv-nsh.exp
./qemu-riscv-nsh.exp

#!/usr/bin/expect
## Expect Script for Testing NuttX with QEMU Emulator

## Wait at most 300 seconds
set timeout 300

## For every 1 character sent, wait 0.01 milliseconds
set send_slow {1 0.01}

## Start the QEMU Emulator for 32-bit RISC-V
spawn qemu-system-riscv32 \
  -semihosting \
  -M virt,aclint=on \
  -cpu rv32 \
  -bios none \
  -kernel nuttx \
  -nographic

## Wait for the prompt and enter `ostest`
expect "nsh> "
send -s "ostest\r"

## Check the response...
expect {
  ## If we see this message, exit normally
  "ostest_main: Exiting with status 0" { 
    ## Terminate the session: Ctrl-A x
    send "\x01x"
    puts "\n===== Test OK\n"
    exit 0 
  }

  ## If timeout, exit with an error
  timeout { 
    ## Terminate the session: Ctrl-A x
    send "\x01x"
    puts "\n===== Error: Test Failed\n"
    exit 1 
  }
}

## Background Task: Automated Testing of Apache NuttX RTOS for QEMU RISC-V 64-bit Flat Build
export BUILD_PREFIX=qemu-riscv-nsh64

## Wait for GitHub Release, then test NuttX
for (( ; ; ))
do
  ## Build Date is today (YYYY-MM-DD)
  BUILD_DATE=$(date +'%Y-%m-%d')
  test_nuttx $BUILD_DATE

  ## Wait a while
  sleep 600
done

## Wait for GitHub Release, then test NuttX on SBC
function test_nuttx {
  ...
  ## Download the NuttX Build
  local date=$1
  NUTTX_ZIP=/tmp/$BUILD_PREFIX-$date-nuttx.zip
  wget -q \
    https://github.com/lupyuen/nuttx-riscv64/releases/download/$BUILD_PREFIX-$date/nuttx.zip \
    -O $NUTTX_ZIP
  ...
  ## Run the NuttX Test
  test-nsh64.sh \
    >/tmp/release-$BUILD_PREFIX.log \
    2>&1
  ...
  ## Upload the Test Log
  upload-nsh64.sh \
    /tmp/release-$BUILD_PREFIX.tag \
    /tmp/release-$BUILD_PREFIX.log
}

## Test Script: Apache NuttX RTOS for QEMU RISC-V 64-bit Flat Build
BUILD_PREFIX=qemu-riscv-nsh64

## Build Date is today (YYYY-MM-DD)
BUILD_DATE=$(date +'%Y-%m-%d')

## Download the latest NuttX build
wget -q https://github.com/lupyuen/nuttx-riscv64/releases/download/$BUILD_PREFIX-$BUILD_DATE/nuttx.zip
unzip -o nuttx.zip

## Write the Release Tag for populating the GitHub Release Notes later
echo "$BUILD_PREFIX-$BUILD_DATE" >/tmp/release-$BUILD_PREFIX.tag

## Boot NuttX on QEMU and run OSTest
wget https://raw.githubusercontent.com/lupyuen/nuttx-riscv64/main/qemu-riscv-nsh64.exp
chmod +x qemu-riscv-nsh64.exp
./qemu-riscv-nsh64.exp

## Upload Test Log to GitHub Release Notes of Apache NuttX RTOS for QEMU RISC-V 64-bit Flat Build
## Parameters: Release Tag, Test Log
repo=lupyuen/nuttx-riscv64
tag=$1
log=$2

## Preserve the Auto-Generated GitHub Release Notes.
## Fetch the current GitHub Release Notes and extract the body text.
gh release view \
  `cat $tag` \
  --json body \
  --jq '.body' \
  --repo $repo \
  >/tmp/upload-nsh64.old

## Find the position of the Previous Test Log, starting with "```"
cat /tmp/upload-nsh64.old \
  | grep '```' --max-count=1 --byte-offset \
  | sed 's/:.*//g' \
  >/tmp/upload-nsh64-previous-log.txt
prev=`cat /tmp/upload-nsh64-previous-log.txt`

## If Previous Test Log exists, discard it
if [ "$prev" != '' ]; then
  cat /tmp/upload-nsh64.old \
    | head --bytes=$prev \
    >>/tmp/upload-nsh64.log
else
  ## Else copy the entire Release Notes
  cat /tmp/upload-nsh64.old \
    >>/tmp/upload-nsh64.log
  echo "" >>/tmp/upload-nsh64.log
fi

## Show the Test Status
grep "^===== " $log \
  | colrm 1 6 \
  >>/tmp/upload-nsh64.log

## Enquote the Test Log without Carriage Return and Terminal Control Characters.
## The long pattern for sed doesn't work on macOS.
echo '```text' >>/tmp/upload-nsh64.log
cat $log \
  | tr -d '\r' \
  | tr -d '\r' \
  | sed 's/\x08/ /g' \
  | sed 's/\x1B(B//g' \
  | sed 's/\x1B\[K//g' \
  | sed 's/\x1B[<=>]//g' \
  | sed 's/\x1B\[[0-9:;<=>?]*[!]*[A-Za-z]//g' \
  | sed 's/\x1B[@A-Z\\\]^_]\|\x1B\[[0-9:;<=>?]*[-!"#$%&'"'"'()*+,.\/]*[][\\@A-Z^_`a-z{|}~]//g' \
  >>/tmp/upload-nsh64.log
echo '```' >>/tmp/upload-nsh64.log

## Upload the Test Log to the GitHub Release Notes
gh release edit \
  `cat $tag` \
  --notes-file /tmp/upload-nsh64.log \
  --repo $repo