Armv8-R AArch32 FreeRTOS VMs on tvmm

Armv8-R AArch32 FreeRTOS VMs on tvmm#

This example demonstrates the L4Re Micro Hypervisor running on Armv8-R AArch32 platforms. It hosts two instances of FreeRTOS, sharing a single CPU core.

package "tvmm" { [FreeRTOS 1] [FreeRTOS 2] } [tinit] --> tvmm : start

Build#

Follow the initial build introductions. Build the particular example via:

$ bob dev --dev-sandbox examples-arm-fvp_base_r/examples::freertos-tvmm -j
[...]
Build result is in dev/dist/examples/freertos-tvmm/1/workspace

Run#

The example runs in the Arm Fixed Virtual Platform emulator. To run it, download the FVP_Base_AEMv8R model of the Arm Architecture FVPs for you host platform. These models are available free of charge:

$ wget https://developer.arm.com/-/cdn-downloads/permalink/FVPs-Architecture/FM-11.28/FVP_Base_AEMv8R_11.28_23_Linux64.tgz
$ tar xf FVP_Base_AEMv8R_11.28_23_Linux64.tgz
$ export PATH="$PWD/AEMv8R_base_pkg-11.28/models/Linux64_GCC-9.3:$PATH"

The example has been tested with the 11.28 release but it should also work with older models. Starting the example assumes that the FVP is availble in $PATH:

$ dev/dist/examples/freertos-tvmm/1/workspace/bootstrap.elf.launch

The above command will start the example and should produce output comparable to the example below:

L4 Bootstrapper
  Build: #5 Fri Feb 21 18:33:40 UTC 2025, 13.2.0
  RAM: 0000000000000000 - 000000007fffffff: 2097152kB
  Total RAM: 2048MB
  Scanning fiasco -serial_esc
  Scanning tinit
  Moving up to 6 modules behind f000000
  Using 'modaddr 0' in modules.list might prevent moving modules.
  moving module 05 { 60000-6cabb } -> { f088000-f094abb } [51900]
  moving module 04 { 53000-5fabb } -> { f07b000-f087abb } [51900]
  moving module 03 { 52000-520a5 } -> { f07a000-f07a0a5 } [166]
  moving module 02 { 49000-51aef } -> { f071000-f079aef } [35568]
  moving module 01 { 41000-4877b } -> { f069000-f07077b } [30588]
  moving module 00 { e000-402db } -> { f036000-f0682db } [205532]
  Loading fiasco
  found node 0 kernel info page (via ELF) at 0xf002000
  Loading tinit
  WARNING: No roottask module for node 0 -- setup might not boot!
  found node 0 kernel options (via ELF) at 0xf003000
  Sigma0 config    node: 0   ip:00140924
  Roottask config  node: 0   ip:00000000
Regions of list 'regions'
    [       9c,        cb] {       30} Root   cpu_boot
    [   140000,    148b07] {     8b08} Sigma0 tinit
    [  f000000,   f000fff] {     1000} Root   mbi_rt
    [  f001000,   f035fff] {    35000} Kern   fiasco
    [  f071000,   f094abb] {    23abc} Root   Module
  Starting kernel fiasco at 0f001038
Hello from Startup::stage2
Reserved 60 MiB as kernel memory.
GIC: Number of IRQs available at this GIC: 256
FPU: Initialize
FPU0: Subarch: 3, Part: 30, Rev: 1, Var: 9, Impl: 41
ARM generic timer: freq=100000000 interval=100000 cnt=6365014
SERIAL ESC: allocated IRQ 37 for serial uart
Not using serial hack in slow timer handler.
Welcome to the L4Re Microkernel!
L4Re Microkernel on arm-32
Rev: 355909f5-dirty compiled with gcc 13.2.0 for ARM FVP Base-R platform    []
Build: #2 Fri Feb 21 18:31:33 UTC 2025

Cache config: ON
Calibrating timer loop...
Timer calibration done.
MDB: use page size: 21
MDB: use page size: 12
tinit: Starting...
tinit: KIP @0xf002000
tinit: found 2035312 KByte free memory
tinit: Node: 0
tinit: start: fork 'tvmm', prio:254, utcb:2, reloc:0x0
tinit: Loading 'tvmm', offset -0xfff000
tinit: Copy in ELF binary section @0x1000/0x8000 from 0x0/0x7f1c
tinit: Copy in ELF binary section @0x9000/0x6000 from 0x8000/0x580
tinit:   defvm 'vm1', prio:16
tinit:     ram 0x1000000/0x200000, load offset 0x0
tinit: Copy in ELF binary section @0x1000080 from 0x80/0x1fc2
tinit: Copy in ELF binary section @0x1003000 from 0x3000/0x8
tinit: Loaded 'guest1.elf' into VM 'vm1': entry @ 0x1000080
tinit:     load 'guest1.elf' entry:0x1000080
tinit:   defvm 'vm2', prio:16
tinit:     ram 0x2000000/0x100000, load offset 0x0
tinit: Copy in ELF binary section @0x2000080 from 0x80/0x1fc2
tinit: Copy in ELF binary section @0x2003000 from 0x3000/0x8
tinit: Loaded 'guest2.elf' into VM 'vm2': entry @ 0x2000080
tinit:     load 'guest2.elf' entry:0x2000080
tinit: Remaining free memory:
tinit:   [    f000 -   13ffff]
tinit:   [  149000 -   ffffff]
tinit:   [ 1200000 -  1ffffff]
tinit:   [ 2100000 -  effffff]
tinit:   [ f036000 -  f070fff]
tinit:   [ f095000 - 7c3fffff]
tinit: Heap: 752/1024 bytes free.
tinit: System RAM usage: 61896 KiB
tinit:   Bootstrap:      152 KiB
tinit:   Kernel:       61652 KiB
tinit:   Userspace:       92 KiB
tinit:     tinit:         36 KiB
tinit:     Apps:          56 KiB
tinit: Task 'tvmm' is ready
tinit: Kernel memory stats:
Buddy_alloc [1024,10]
  [1024] 0x7c409c00(0) -> 00000000(0) == 1K (1024)
  [2048] 00000000(0) == 0K (0)
  [4096] 00000000(0) == 0K (0)
  [8192] 0x7c462000(3) -> 00000000(0) == 8K (8192)
  [16384] 0x7c464000(4) -> 00000000(0) == 16K (16384)
  [32768] 0x7c468000(5) -> 00000000(0) == 32K (32768)
  [65536] 0x7c470000(6) -> 00000000(0) == 64K (65536)
  [131072] 00000000(0) == 0K (0)
  [262144] 00000000(0) == 0K (0)
  [524288] 0x7ff80000(9) -> 0x7ff00000(9) -> 0x7fe80000(9) -> 0x7fe00000(9) -> 0x7fd80000(9) -> 0x7fd00000(9) ... == 60928K (62390272)
sum of available memory: 61049K (62514176)
Used 0%, 384KiB out of 61433KiB of Kmem
Hello from FreeRTOS!
task1
task2
Hello from FreeRTOS!
task1
task2

The two FreeRTOS VMs will print from their two tasks in a regular interval. You can stop the example by pressing Ctrl+C.

Detailed description#

The exemple is built by the recipes/examples/freertos-tvmm.yaml recipe. The Tinit configuration is stored in recipes/examples/freertos-tvmm/freertos.inittab:

start tvmm utcb:2
  defvm vm1 0x10
    ram  0x01000000 0x200000
    load guest1.elf
  end

  defvm vm2 0x10
    ram 0x02000000 0x100000
    load guest2.elf
  end
end

This starts a single tvmm instance, hosting two VMs (vm1 and vm2). Each VM uses a different guest ELF image that were built by the recipes/examples/guests/freertos-tvmm.yaml recipe. Please refer to the tinit detailed desciption for all the configuration file details.

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