marqs85/pulpino_qsys_test

Pulpino Qsys integration example

Overview

This is an example project demonstrating integration of Pulpino zero-riscy RISC-V core into Altera Platform Designer platform (formerly called Qsys or SOPC). HW integration code/scripts are on its own submodule under ip subdirectory, and sw subdirectory contains an example application that prints "Hello World" and lights up a few LEDs using other Altera platform IP (jtag_uart and pio). The code is targeted for DE2-115 development board, but it can be simulated on Modelsim-Altera without real HW or easily ported to other Altera FPGAs. The instructions below are mainly made with *nix systems in mind but everthing should work with Cygwin on Windows as well.

Prequisites

• Quartus Lite including Cyclone IV device support, Nios II EDS and ModelSim-Intel FPGA Edition.
• RISC-V GNU Compiler Toolchain
• (Optional) DE2-115 development board

SW build procedure

1. Download, configure, build and install RISC-V toolchain with Newlib + multilib support:

git clone --recursive https://github.com/riscv/riscv-gnu-toolchain
cd riscv-gnu-toolchain
./configure --prefix=/opt/riscv --enable-multilib
make
make install

2. Compile custom binary to IHEX converter:

cd pulpino_qsys_test
gcc tools/bin2hex.c -o tools/bin2hex

3. Compile example application image

cd sw
make

RTL (bitstream) buid procedure

1. Load the project (pulpino_qsys_test.qpf) in Quartus
2. Generate QSYS output files
   • Open Platform Designer (Tools -> Platform Designer)
   • Load platform configuration (sys.qsys)
   • Generate output (Generate -> Generate HDL, Generate)
   • Close Platform Designer
3. Generate FPGA bitstream (Processing -> Start Compilation)

Run testbench on simulator

1. Tools -> Run Simulation Tool -> RTL Simulation
2. Check that "Hello World" is printed on simulator console and "led" on waveform window changes into "11110000"

Run test on DE2-115

1. Program bitstream (output_files/pulpino_qsys_test.sof) on the board
2. Ensure that LEDG[7:4] are turned on
3. Open nios2-terminal and check that "Hello World" is printed out

Reprogram RISC-V dynamically (on DE2-115)

1. Modify sw/hello.c (e.g. change LED output from 0xf0 to 0xff)
2. Run "make rv-reprogram" on sw subdirectory
3. Ensure that board is reset and updated LED pattern is shown
4. (Optional) If you want to update bitstream with the new RISC-V code (no RTL changes), just run "Processing->Update Memory Initialization File" and "Processing->Start->Start Assembler" in Quartus

TODO

• Better linker script
• Get rid of hard-coded address map values
• Adapt Altera BSP/HAL system