/JuiceVm

The juice virtual machine was born in 2020, with the goal of realizing the smallest virtual machine of RISC-V that can run the latest kernel mainline. At the beginning of the design, it runs on a platform with only 100 KB of RAM, which does not exceed the number of C99. Three-party dependence.

中文

JUICE VM

Introduction

The project began in 2020.Juice Vm is a small RISC-V virtual machine and run the latest kernel.The chip which contain hundreds of KB RAM can run this virtual machine,but it wouldn't contain any third-party libraries.

Juice Vm follow gcc C99 stardard,without any third-party library.Therefore,it is really easy to read and it support many platforms.

There is only 12523 lines and 36104 words in the project without any annotation .Therefore it is really small.

The Advantage of Juice Vm

  • Consume little memory

  • Support some platforms easily.

The feature of Juice Vm

  • ISA(Instruction Set Architecture)：RV64IMASU.
  • Suport mtime in M-mode,U-mode,S-mode
  • Super small uart,only contain two Register:read and write
  • Super samll MMU(support SV39)
  • Support exception and interruption with official RISC-V stardard

Juice Vm's statistics

JUICE VM

Juice Vm's address

Version Start Address Size(Byte) Register Statement Macro definition
c21682d3 0x80000000 0x12C00000 SRAM internal storage RV_CPU_SIM_RAM_START_ADDR RV_CPU_SIM_RAM_SIZE
c21682d3 0x92C00000 0x1 UART_WRITE uart send register pdev_uart0_write_addr
c21682d3 0x92C00001 0x1 UART_READ uart recv register pdev_uart0_read_addr
c21682d3 0x92C00002 0x1 UART_STATE uart state register pdev_uart0_state_addr pdev_uart0_free_state pdev_uart0_readbusy_state
c21682d3 0x92C00003 0x8 mtime current count register pdev_mtime_mtime_addr
c21682d3 0x92c00007 0x8 mtimecmp compare register pdev_mtime_mtimecmp_addr

The software process of Project

  • Support the C program
  • Support freertos
  • Support mbedtls
  • Pass mmu sv39 test
  • Pass mtime test
  • Support opensbi Link
  • Support rt-thread ,Thanks for @熊大和@Andy Chen Link
  • Support kernel 5.0.0 Link
  • Upload GCC toolchain Link
  • Support GDB TODO
  • SUpport RT-SMART TODO

Get started

  • UBUNTU/DEBIAN APT install
    echo "deb http://xiaohui.mongoyun.com:3333/ trusty main" | sudo tee -a /etc/apt/sources.list
    wget -O - http://xiaohui.mongoyun.com:3333/key/deb.gpg.key | sudo apt-key add -
    sudo apt update
    sudo apt install juicevm
    juicevm
  • CENTOS
    echo "deb http://xiaohui.mongoyun.com:3333/ trusty main" | sudo tee -a /etc/apt/sources.list
    wget -O juice_vm_release_for_Linux_laster.zip https://github.com/juiceRv/JuiceVm/raw/master/juice_vm_release_for_Linux_laster.zip
    unzip juice_vm_release_for_Linux_laster.zip
    cd juice_vm_release_for_Linux_c21682d3/juice_vm_release_for_Linux
    sudo chmod +x juice_vm_for_Linux.out
    ./juice_vm_for_Linux.out
  • WINDOW

Compile

Example

The Shot of freertos

JUICE VM FreeRtos

The Shot of rt-thread

JUICE VM RT-thread

The Shot of linx 5.0.0

JUICE VM linux kernel

Parameters Specification

Parm Name statement
t enable test mode Enter test mode
When appearing the following statement,the machine would end up,x3_gp register's value is 1 and x17_a7 register's vaule is 93时,it cause ecall exception。when x10_a0 register's value is 0 ,it print pass，otherwise it print "faile"
T enable trap debug mode enable exception mode and it will print current exception information
d enable debug mode Open all debug option in vitural machine and print debug ,include ISA,running process,register list ,csr list and etc.
c print cst operation msg enable debug csr register(read and write register) and print all the register values.
a diable all debug msg Disable all debug message
x enable test mode for exception It caused by exception
g enable better readability printing None
e disable all error msg None
i enable all instr debug msg None
m enable mmu debug msg None
p print mmu page 8 byte data None
P print mmu page 4K Byte data None
s uart addr not use mmu translation Enalbe mmu translation,and ignore uart address.Control the uart by read and write uart physical address when enble mmu
S switch mode debug info enable debug when switching the mode.It print debug information in m-mode,s-mode and u-mode
M disable mmu err msg Disable debug about Page missing,exception
r enable trap debug msg Print more detailed debug about interruption
A enable addr translation debug print None
L(n) log mode output_mode_sel n = 0 -> stdout
1 -> log_buf UNIX SYS ONLY(buf_size:(2900))
2 -> none
Choose output mode，1，stardard ouput. 2，Store in a buffer when the code is running.Ouput 2900Byte buffer when the code exit. 3，No ouput。
l enable endless loop check (RV_ENDLESS_LOOP_CHECK_EXIT_CNT:(3)) Enable loop watcher,when it run the same introduction three times continuously(include registers and csr register value wouldn't change),end the vm.You can run the vm with -L in order to debug the fireware.It would be bad loop when show assert

Community support

Thanks for whycan ：https://whycan.com/t_5844.html

CHANGE LOG

2021-05-25

20210524 juice_vm_release_for_Linux_c21682d3.zip：

  1. fix mtime interruption bug in m-mode,s-mode and u-mode
  2. fix ecall bug in s-mode
  3. fix issue about interruption in s-mode and u-mode,fix the csr register.
  4. support linux(5.0.0)

20210508：

  1. release the package in ubuntu20.04,thanks for @XBOOT
  2. support div introduction set
  3. fix divuw，divw，remu，remw，amomin.w，amoswap.w introduction error

20210427：

Support RT-Thread OS ,please refer: https://github.com/RT-Thread/rt-thread/tree/master/bsp/juicevm

2021042:

software specification

1.Support rt-thread

Update parameters：

  1. -L:Support different output mode with
  2. -l:End the code when the machine enter bad loop
  3. -r:enalbe trace debug
  4. Add Alive logo
  5. -T: Print compilation information when the code is running
  6. support m-mode
  7. support s-mode(u-mode todo)

202210306:

software specification

  1. Support c program
  2. Supoort freertos
  3. Support mbedtls
  4. Support mmu sv39 test
  5. Support mtimer test
  6. Support opensbi

Update parameters:

  • -m enable mmu debug

Issue

  • 1113e998 add sfence.vma instr
  • f118d476 add print instr support
  • 1e3e7204 add AMOSWAP.D LR.D and SC.D instr support
  • 686741ea add AMOSWAP.D LR.D and SC.D instr support
  • f2f699c0 add -i arg to enable instr print support
  • 113f66da add misa csr support
  • 19cf60d1 fix divu err
  • ad512e54 add divu remw and remu instr
  • 9abc0566 fix mem overflow
  • 0ceb663e fix divw instr and add REMW instr
  • 10a2ea78 fix divw instr
  • 9c93c4ce add amoswap.w , mul and divw instr
  • df10ad45 change the fireware start addr to 0x80000000
  • d31b4ac1 add amoadd.w inst

2021-03-06 :

finish risc-v vitual machine with muc and there is within 5000 lines c codes.

Base bu rv64i

Support mtime，small uart and mmu sv39.

Update Parameters:

  • -a close all debug
  • -e close error debug
  • -g format print
  • -d enable all debug (include register and csr list)
  • -i enalbe decode debug
  • -m enable mmu debug

Software Specification*

  1. Support c program
  2. Supoort freertos
  3. Support mbedtls
  4. Support mmu sv39 test
  5. Support mtimer test
  6. Support opensbi

Thanks

Contact us

juicemail@163.com