Learn with SHAKTI

Using Arty-7 100T with SHAKTI-SDK

STEP 1: Setting up the SHAKTI-SDK

1. Download the SHAKTI-SDK repository

git clone --recursive https://gitlab.com/shaktiproject/software/shakti-sdk.git

2. Open a new terminal and Run the following commands to verify the SHAKTI-TOOLS Installation :

which riscv64-unknown-elf-gcc

/path-to-shakti-tools/riscv64/bin/riscv64-unknown-elf-gcc

which spike

/path-to-shakti-tools/riscv64/bin/spike

which pk

/path-to-shakti-tools/riscv64/riscv64-unknown-elf/bin/pk

which openocd

/path-to-shakti-tools/bin/openocd

3. Please ensure Arty-7 100t board connected to the system using the microUSB cable, is up and running.

STEP 2: Write a simple C program to print Hello world

1. The device required is UART. Move inside the uart_applns folder under shakti-sdk

cd shakti-sdk/software/examples/uart_applns

2. Create a folder first under uart_applns.

3. Open a file in text editor and Copy paste the below content in it and save it as first.c under uart_applns/first folder.

#include "uart.h"

int main()
{
printf("hello, world");
return (0);
}

STEP 3: Compile

To compile programs more efficiently, GNU’s make utility is used. This is useful when we need to include several source files and header files in our application.

To use the make utility, a Makefile is needed. The Makefile includes the commands to compile and link a program and generate the required executables.

It has support for different target boards and applications. SHAKTI-SDK hosts the Makefiles to support development in Arty-7 boards.

For the application "first", Please follow the below steps:

Copy and paste the Makefile from hello folder to first folder.
Make a new entry for the application in the ’existing Makefile’ under examples folder.

make help:

It lists the possible commands supported in the Makefile.

make help

STEP 4: Build

1. Move inside the shakti-sdk folder and compile the first.c created under uart_applns for shakti-sdk.

cd shakti-sdk

make software PROGRAM=first TARGET=artix7_100t

Note: first.shakti, which is the executable required for SHAKTI is generated under shakti-sdk/software/examples/uart_applns/first/output.

STEP 5: Execution

The Arty-7 100T board is programmed with SHAKTI C class SoC. Please ensure Arty-7 100T board is connected to the the Host PC.

The Arty-7 100T board should be attached to the OpenOCD debugger, in order to debug your program using the RISC-V GNU Debugger (GDB) software. Read how RISC-V GDB and OpenOCD work together to establish a connection between the Microprocessor and Host PC.
Since we have built the application, already. We can straight away load it to the Arty-7 100T board and test.

The following steps list out the actions to be taken,

If you face any error while running any command, Please refer FAQ section.

TERMINAL 1: Open a serial port in this terminal, Here the output of the C program is displayed.

sudo miniterm.py /dev/ttyUSB0 19200

--- Miniterm on /dev/ttyUSB0  19200,8,N,1 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---

Note: "/dev/ttyUSB0" - ttyUSB means "USB serial port adapter" and the "0" ( "0" or "1" or "2") is the USB device number to which the board is connected and 19200 is the default baud rate.

TERMINAL 2: Open a new terminal and move to shakti-sdk folder. Here, run OpenOCD with the ftdi.cfg.

cd shakti-sdk

cd ./bsp/third_party/artix7_100t

sudo $(which openocd) -f ftdi.cfg
[sudo] password for rise:

Open On-Chip Debugger 0.10.0+dev-00615-gfd9c54b (2019-07-12-15:10)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
adapter speed: 1000 kHz
none separate
Info : auto-selecting first available session transport "jtag". To
override use 'transport select '.
Info : Simple Register based Bscan Tunnel Selected
Info : clock speed 1000 kHz
Info : JTAG tap: riscv.cpu tap/device found: 0x13631093 (mfg: 0x049
(Xilinx), part: 0x3631, ver: 0x1)
Info : datacount=12 progbufsize=0
Warn : We won't be able to execute fence instructions on this target.
Memory may not always appear consistent. (progbufsize=0, impebreak=0)
Info : Examined RISC-V core; found 1 harts
Info :  hart 0: XLEN=64, misa=0x800000000014112d
Info : Listening on port 3333 for gdb connections
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : accepting 'gdb' connection on tcp/3333

TERMINAL 3: Open a new terminal and move to shakti-sdk folder. Now start the gdb debugging session by running below command. What are the most used RISC-V GDB Commands?

riscv64-unknown-elf-gdb

GNU gdb (GDB) 8.0.50.20170724-git
Copyright (C) 2017 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=x86_64-pc-linux-gnu
--target=riscv64-unknown-elf".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
.
 Find the GDB manual and other documentation resources online at:
.
For help, type "help".
Type "apropos word" to search for commands related to "word".

(gdb) set remotetimeout unlimited

(gdb) target remote localhost:3333

Remote debugging using localhost:3333
warning: No executable has been specified and target does not support
determining executable automatically.  Try using the "file" command.
Python Exception  'gdb.Inferior'
object has no attribute 'progspace':
0x0000000000000004 in ?? ()

(gdb) file ./software/examples/uart_applns/first/output/first.shakti

A program is being debugged already.
Are you sure you want to change the file? (y or n) y
Reading symbols from ./software/examples/uart_applns/first/output/first.shakti...(no debugging symbols found)...done.

(gdb) load

Loading section .text.init, size 0x1c2 lma 0x80000000
Loading section .tohost, size 0x48 lma 0x80001000
Loading section .text, size 0x1018 lma 0x80001048
Loading section .rodata, size 0x1b0 lma 0x80002060
Start address 0x80000000, load size 5074
Transfer rate: 11 KB/sec, 1268 bytes/write.

(gdb)  c

Continuing.

Switch to TERMINAL 1 to view the output of the C program.

sudo miniterm.py /dev/ttyUSB0 19200

--- Miniterm on /dev/ttyUSB0  19200,8,N,1 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---

hello, world