In order to be able to run the examples in the examples/ directory, you would need to have the following installed:
sudo apt install -y binutils \
make \
binutils-riscv64-linux-gnu \
binutils-arm-none-eabi \
gcc-aarch64-linux-gnu \
gcc-riscv64-linux-gnu \
g++-riscv64-linux-gnu \
gcc-arm-none-eabi \
qemu-system-riscv64 \
qemu-system-aarch64 \
qemu-system-arm \
qemu-system \
gdb-multiarch \
gcc-riscv64-linux-gnu \
openocd \
minicom \
python3-pip
This would allow compiling, running, uploading and debugging the code.
This will convert the text based GDB into a nice dashboard with all registers and source code etc visible.
wget -P ~ https://git.io/.gdbinit
pip3 install pygments
Following in examples/emulation/ are qemu based.
armv7A-32-Rpi2 armv7M-32 armv8A-32-RPi3b armv8A-64 armv8A-64-smp armv8M-32 riscv-64
Get into riscv-64/ for the purposes of this demo:
cd examples/emulation/riscv-64
To build the source, simply execute
make
This will result in output something like below:
Detected Configuration
*
|- PROJECT : shell
|- BUILD USER : itankar
|- BUILD HOST : sandbox
|- SHELL VERSION : 6309660
|- USER REPO VERSION : 6309660
|- SHELL ROOT : /home/itankar/early-bringup-tool/shell
|- PROJECT ROOT : /home/itankar/early-bringup-tool/examples/emulation/riscv-64
|- OPTIMIZATION : 0
*
|- TOOLCHAIN : riscv64-linux-gnu-
|- STARTUP : /home/itankar/early-bringup-tool/shell/startup/riscv64.S
|- LAYOUT FILE : /home/itankar/early-bringup-tool/shell/scatter/layout.ld
|- RAM BASE : 0x80000000
|- RAM SIZE : 0x4000000
`- UART BASE : 0x10000000
>> If incorrect, please set these Variables in Makefile <<
...
generating shell.elf
section size:
text data bss dec hex filename
5722 1240 88 7050 1b8a shell.elf
generating shell.bin
Done!
shell.elf and shell.bin are the compiled outputs. These can be run on the riscv64 qemu target. Along with these files, the following helper files will also be generated - shell.elf.lst, shell.elf.map
Once done with the compilation above, use the following command to run the binaries on the qemu target.
make run
You should see a prompt as below:
$ make run
Build: [6309660]:[6309660] - [itankar@sandbox] - Mar 24 2022 - 05:53:50
#
Typing help should reveal all the available commands. Like below:
$ make run
Build: [6309660]:[6309660] - [itankar@sandbox] - Mar 24 2022 - 05:53:50
# help
hello
Echoes the commandline
usage: hello <any string>
r32
reads a 32 bit memory location
w32
writes a 32 bit value to a memory location
read
Reads number of bytes from memory
help
Prints all available commands
printf_examples
Prints example usage of printf
echo
Turn input echo on/off
version
Prints details of the build
#
hello command is implemented in the hello.c file and serves as an example of how more commands can be added.
Exit QEMU: ctrl+a then x to exit.
If you want to debug by using gdb you would need to open two terminals within the location examples/emulation/riscv-64/ and start the qemu run with the board halted on terminal and then connect gdb to it from the second terminal.
On first terminal execute:
make run_debug
This will start the qemu target and hold the CPU in reset.
On the second terminal, execute:
make debug
This will then start gdb and attach it to the qemu target. You should see output as below:
$ make debug
...
Remote debugging using localhost:1234
0x0000000000001000 in ?? ()
(gdb)
You can now use familiar gdb commands at the (gdb) prompt, like break, continue, run etc to debug the target further. If the GDB Dashboard in installed, the view shoyuld be some what as below:
$ make debug
...
Reading symbols from shell.elf...
Remote debugging using localhost:1234
0x0000000000001000 in ?? ()
─── Assembly ───────────────────────────────────────────────────────────────────
0x0000000000001000 ? auipc t0,0x0
0x0000000000001004 ? addi a2,t0,40
0x0000000000001008 ? csrr a0,mhartid
0x000000000000100c ? ld a1,32(t0)
0x0000000000001010 ? ld t0,24(t0)
0x0000000000001014 ? jr t0
0x0000000000001018 ? unimp
0x000000000000101a ? 0x8000
0x000000000000101c ? unimp
0x000000000000101e ? unimp
─── Breakpoints ────────────────────────────────────────────────────────────────
─── Expressions ────────────────────────────────────────────────────────────────
─── History ────────────────────────────────────────────────────────────────────
─── Memory ─────────────────────────────────────────────────────────────────────
─── Registers ──────────────────────────────────────────────────────────────────
zero 0x0000000000000000 ra 0x0000000000000000 sp 0x0000000000000000
gp 0x0000000000000000 tp 0x0000000000000000 t0 0x0000000000000000
t1 0x0000000000000000 t2 0x0000000000000000 fp 0x0000000000000000
s1 0x0000000000000000 a0 0x0000000000000000 a1 0x0000000000000000
a2 0x0000000000000000 a3 0x0000000000000000 a4 0x0000000000000000
a5 0x0000000000000000 a6 0x0000000000000000 a7 0x0000000000000000
s2 0x0000000000000000 s3 0x0000000000000000 s4 0x0000000000000000
s5 0x0000000000000000 s6 0x0000000000000000 s7 0x0000000000000000
s8 0x0000000000000000 s9 0x0000000000000000 s10 0x0000000000000000
s11 0x0000000000000000 t3 0x0000000000000000 t4 0x0000000000000000
t5 0x0000000000000000 t6 0x0000000000000000 pc 0x0000000000001000
─── Source ─────────────────────────────────────────────────────────────────────
─── Stack ──────────────────────────────────────────────────────────────────────
[0] from 0x0000000000001000
─── Threads ────────────────────────────────────────────────────────────────────
[1] id 1 from 0x0000000000001000
─── Variables ──────────────────────────────────────────────────────────────────
────────────────────────────────────────────────────────────────────────────────
>>>
gdb commands can be used as usual at the >>> prompt.
Execute the following to clean the current working directory
make clean
examples/physical/hifive/ implements a port for a hifive_rev_b board. The code can be
compiled and uploaded as follows -
Get into the directory
cd examples/physical/hifive/
Trigger the build process
make
following should be seen
$ make
...
generating shell.elf
section size:
text data bss dec hex filename
2818 615 8 3441 d71 shell.elf
generating shell.bin
Done!
We use openocd to upload to the board and to debug.
In case of an actual board the prompt will be available on the uart. Thus we would need to connect to the uart using minicom. Following command can be used:
sudo minicom -D /dev/ttyACM0
Something like below should be seen:
Welcome to minicom 2.8
OPTIONS: I18n
Port /dev/ttyACM0, 08:35:52
Press CTRL-A Z for help on special keys
...
Following command will upload the compiled binary to the board.
make upload
the following should be seen:
$ make upload
Uploading...Open On-Chip Debugger 0.11.0
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
Info : J-Link OB-K22-SiFive compiled Oct 30 2020 11:20:31
Info : Hardware version: 1.00
Info : VTarget = 3.300 V
Info : clock speed 4000 kHz
Info : JTAG tap: riscv.cpu tap/device found: 0x20000913 (mfg: 0x489 (SiFive Inc), part: 0x0000, ver: 0x2)
Info : datacount=1 progbufsize=16
Info : Disabling abstract command reads from CSRs.
Info : Examined RISC-V core; found 1 harts
Info : hart 0: XLEN=32, misa=0x40101105
Info : starting gdb server for riscv.cpu.0 on 3333
Info : Listening on port 3333 for gdb connections
Info : Found flash device 'issi is25lp032' (ID 0x0016609d)
Ready for Remote Connections
Info : JTAG tap: riscv.cpu tap/device found: 0x20000913 (mfg: 0x489 (SiFive Inc), part: 0x0000, ver: 0x2)
** Programming Started **
Info : Disabling abstract command writes to CSRs.
** Programming Finished **
** Verify Started **
** Verified OK **
** Resetting Target **
Info : JTAG tap: riscv.cpu tap/device found: 0x20000913 (mfg: 0x489 (SiFive Inc), part: 0x0000, ver: 0x2)
shutdown command invoked
Done :)
The prompt should be seen on the minicom window.
Welcome to minicom 2.8
OPTIONS: I18n
Port /dev/ttyACM0, 08:35:52
Press CTRL-A Z for help on special keys
Bench Clock Reset Complete
ATE0--> Send Flag error: #255 #255 #255 #255 AT+BLEINIT=0--> Send Flag error: #255 #255 #255 #255 AT+CWMODE=0--> Send Flag er
Build: [6309660]:[6309660] - [itankar@sandbox] - Mar 24 2022 - 05:53:50
#
...
We can now type commands at the prompt much like in case of the qemu based targets.
We can use make debug and make gdb on two separate terminals to start a gdb server via openocd and then connect gdb to it. Executing each command should show the following -
Terminal 1:
$ make debug
GDB server active...
Use Ctrl+c to close the server!
Terminal 2:
$ make gdb
Reading symbols from shell.elf...
0x00001004 in ?? ()
─── Assembly ───────────────────────────────────────────────────────────────────
0x00001004 ? auipc t0,0x0
0x00001008 ? lw t1,-4(t0)
0x0000100c ? slli t1,t1,0x3
0x00001010 ? add t0,t0,t1
0x00001014 ? lw t0,252(t0)
0x00001018 ? jr t0
0x0000101c ? unimp
0x0000101e ? unimp
0x00001020 ? unimp
0x00001022 ? unimp
─── Breakpoints ────────────────────────────────────────────────────────────────
─── Expressions ────────────────────────────────────────────────────────────────
─── History ────────────────────────────────────────────────────────────────────
─── Memory ─────────────────────────────────────────────────────────────────────
─── Registers ──────────────────────────────────────────────────────────────────
zero 0x00000000 ra 0x20010a2c sp 0x80003f80
gp 0x80000d80 tp 0x00000000 t0 0x00000000
t1 0x00000000 t2 0x800005d0 fp 0x00000000
s1 0x00000000 a0 0x80000068 a1 0x20010c2c
a2 0x20010c2c a3 0x20010c24 a4 0x0000000f
a5 0x10013000 a6 0x00000003 a7 0x00000000
s2 0x00000000 s3 0x00000000 s4 0x00000000
s5 0x00000000 s6 0x00000000 s7 0x00000000
s8 0x00000000 s9 0x00000000 s10 0x00000000
s11 0x00000000 t3 0x80000170 t4 0x00000000
t5 0x00000000 t6 0x00000000 pc 0x00001004
utvt 0x00000000 vcsr 0x00000000 unxti 0x00000000
uintstatus 0x00000000 uscratchcsw 0x00000000 uscratchcswl 0x00000000
stvt 0x00000000 snxti 0x00000000 sintstatus 0x00000000
sscratchcsw 0x00000000 sscratchcswl 0x00000000 vsstatus 0x00000000
vsie 0x00000000 vstvec 0x00000000 vsscratch 0x00000000
vsepc 0x00000000 vscause 0x00000000 vstval 0x00000000
vsip 0x00000000 vsatp 0x00000000 mtvt 0x00000000
mstatush 0x00000000 mnxti 0x00000000 mintstatus 0x00000000
mscratchcsw 0x00000000 mscratchcswl 0x00000000 mtinst 0x00000000
mtval2 0x00000000 htimedelta 0x00000000 hcounteren 0x00000000
hgeie 0x00000000 htimedeltah 0x00000000 htval 0x00000000
hvip 0x00000000 htinst 0x00000000 hgatp 0x00000000
hgeip 0x00000000
─── Source ─────────────────────────────────────────────────────────────────────
─── Stack ──────────────────────────────────────────────────────────────────────
[0] from 0x00001004
[1] from 0x20010a2c in shell+220 at /home/itankar/early-bringup-tool/shell/shell.c:204
[2] from 0x00000000
─── Threads ────────────────────────────────────────────────────────────────────
[1] id 0 from 0x00001004
─── Variables ──────────────────────────────────────────────────────────────────
───────────────────────────────────────────────────────────────────────────────-
JTAG tap: riscv.cpu tap/device found: 0x20000913 (mfg: 0x489 (SiFive Inc), part: 0x0000, ver: 0x2)
keep_alive() was not invoked in the 1000 ms timelimit. GDB alive packet not sent! (2096 ms). Workaround: increase "set remotetimeout" in GDB
>>>