Working with machines

Renode allows to easily handle emulations spanning multiple machines.

Creating machines

In the beginning, the emulation is empty as there is no machine to run. In order to add an empty one, execute:

(monitor) mach create
(machine-0)

This creates the first machine, which, if you don’t give it a custom name, will be indexed from 0 (and thus called machine-0). This command also switches the Monitor’s context to this new machine.

Executing the same command again will create another machine, called machine-1:

(machine-0) mach create
(machine-1)

You can create a machine with a custom name by providing it as the argument:

(monitor) mach create "my-machine"
(my-machine)

To list all created machines together with their names and indices, type:

(my-machine) help mach

Switching between machines

When you want to switch the Monitor’s context to another machine type:

(machine-1) mach set "machine-0"
(machine-0)

Instead of the machine’s name, you can use its index as well:

(machine-1) mach set 0
(machine-0)

Loading platforms

Once a machine is created, it contains only one peripheral - the system bus called simply sysbus. There is no memory or CPU, so the machine is not yet ready to execute any code.

To list all peripherals, execute:

(machine-0) peripherals
Available peripherals:

  sysbus (SystemBus)

To load a predefined platform (in this example, Microsemi MiV), type:

(machine-0) machine LoadPlatformDescription @platforms/cpus/miv.repl
(machine-0) peripherals
Available peripherals:
sysbus (SystemBus)
│
├── clint (CoreLevelInterruptor)
│     <0x44000000, 0x4400FFFF>
│
├── cpu (RiscV)
│     Slot: 0
│
├── ddr (MappedMemory)
│     <0x80000000, 0x83FFFFFF>
│
├── flash (MappedMemory)
│     <0x60000000, 0x6003FFFF>
│
├── gpioInputs (MiV_CoreGPIO)
│     <0x70002000, 0x700020A3>
│
├── gpioOutputs (MiV_CoreGPIO)
│     <0x70005000, 0x700050A3>
│
├── plic (PlatformLevelInterruptController)
│     <0x40000000, 0x43FFFFFF>
│
├── timer0 (MiV_CoreTimer)
│     <0x70003000, 0x7000301B>
│
├── timer1 (MiV_CoreTimer)
│     <0x70004000, 0x7000401B>
│
└── uart (MiV_CoreUART)
      <0x70001000, 0x70001017>

The format of .repl (Renode platform) files is presented in the Describing platforms section.

Accessing and manipulating peripherals

When you are in the context of a machine in the Monitor you can reference peripherals by name. You can read and write a peripheral’s properties as well as execute some actions on them. The set of available properties and operations depends on the type of peripheral.

For example, to check memory size, execute:

(machine-0) sysbus.ddr Size

To call an action on the peripheral, use the same syntax but replace Size with the action name, e.g., ZeroAll:

(machine-0) sysbus.ddr ZeroAll

To get the complete list of available properties or actions, just enter the peripheral’s name:

(machine-0) sysbus.ddr
The following methods are available:
- Void DebugLog (String message)
- Void Dispose ()
[...]
- Void WriteWordUsingDwordBigEndian (Int64 address, UInt16 value)
- Void ZeroAll ()
Usage:
sysbus.ddr MethodName param1 param2 ...
The following properties are available:
- Int32 SegmentCount
    available for 'get'
- Int32 SegmentSize
    available for 'get'
- Int64 Size
    available for 'get'
Usage:
- get: sysbus.ddr PropertyName
- set: sysbus.ddr PropertyName Value

The Usage sections describe the proper syntax for accessing the peripheral’s features.

Loading binaries

Once the platform is created and configured, you can upload the software onto it. Renode allows you to run exactly the same executable as on the real hardware, which means there is no need to alter the binary or recompile the source.

In Renode, you can use local binaries or load them via HTTPS. If you do not have a binary at your disposal, you can use this sample Zephyr Shell sample for MiV.

To load a local .elf file into memory, execute:

(machine-0) sysbus LoadELF @my-project.elf

To load a binary via HTTPS:

(machine-0) sysbus LoadELF @https://remote-server.com/my-project.elf

Note

If you load multiple ELF files, Renode will look for the lowest loaded section of the last ELF file to locate the initial PC (or vector table offset on Cortex-M machines). That means the last ELF you load will set up your CPU starting point.

To override this, you can set the initial values manually, using:

sysbus.cpu PC 0xYourValue

or, on Cortex-M:

sysbus.cpu VectorTableOffset 0xYourValue

Renode supports other executable formats like raw binary, UImage and HEX as well. To load them, use LoadBinary, LoadUImage or LoadHEX accordingly.

Clearing the emulation

If you want to switch to another project, you can drop the whole emulation::

(machine-0) Clear

All machines, peripherals, and loaded binaries will be removed, and Renode will return to its initial state.


Last update: 2024-06-20