Deploying a Zephyr Wi-Fi DHCP client application on the CROSSCON Hypervisor

Introduction

Virtualization traditionally relies on high-end architectures with hardware support, but what about low-cost, power-efficient MCUs? Can devices like that use the benefits of virtualization? The CROSSCON Hypervisor tackles this challenge by enabling virtualization on ARM MCUs. In this post, we’ll explore how CROSSCON runs a Zephyr application inside its virtual machine and what makes this approach possible.

The CROSSCON Hypervisor

The CROSSCON Hypervisor is a static partitioning hypervisor that originated as a fork of the Bao Hypervisor. Over time, CROSSCON has grown into an independent project with its own features and direction, while keeping the same core principles of simplicity and minimalism that Bao is known for.

Like other hypervisors, CROSSCON implements three key aspects of virtualization:

  1. Context separation – either through static assignment of CPU cores to virtual machines or, on single-core platforms, through a scheduler.
  2. Memory separation – each virtual machine is isolated in its own memory region, with optional shared regions defined for communication.
  3. Interrupt separation – interrupts are delivered only to the virtual machine assigned to handle them.

This blog post demonstrates CROSSCON running on the LPCXpresso55S69 board, which features an ARM Cortex-M33 core and a secondary Cortex-M33 co-processor. While the co-processor is present, it lacks critical features such as an MPU, FPU, DSP, ETM, and TrustZone, so CROSSCON relies only on the primary core.

For a hypervisor, features like an MPU or TrustZone are crucial because they provide hardware-based memory protection and isolation, while an FPU or DSP can boost performance for specific workloads. Since these are not available on the co-processor, CROSSCON leverages the primary Cortex-M33 core and uses its own scheduler to run multiple virtual machines. Unlike high-end architectures that include an MMU or GIC, CROSSCON instead depends on the TrustZone-related SAU and IDAU units of ARMv8-M to enforce memory and interrupt separation.

crosscon-zdm

For the curious ones, check the ARMv8-M TrustZone documentation. But let’s focus on the demo now.

The demo goal

Here is the demo architecture:

dhcp-crosscon-zdm

The demo had two goals:

  1. Run a Zephyr RTOS application with network device access inside a CROSSCON Hypervisor virtual machine on LPCXpresso55S69 (VM1 in the diagram).
  2. Run two CROSSCON virtual machines side-by-side on LPCXpresso55S69, where one VM runs a bare-metal application (VM0) and the other runs the Zephyr application from goal 1.

To achieve this demo, we used:

This post is not a step-by-step guide, but rather a walkthrough of how the demo was built and the lessons learned along the way. If you’d like to reproduce the setup, check out the demo repository.

Implementation

The CROSSCON Hypervisor is a static partitioning hypervisor that receives the configuration during the compilation process via C language structures defined in a specific configuration file. Hence, launching an application in the CROSSCON Hypervisor virtual machine consists of the following steps:

  1. Set the application entry and load addresses.
  2. Assign memory to the virtual machine in which the application will be running.
  3. Assign memory and interrupts to the memory-mapped peripherals.

In theory, providing this information and compiling the final image should be enough to launch any application. In practice, it’s not that straightforward. If something is misconfigured, the hypervisor does not provide clear error feedback, so diagnosing issues often requires deeper insight. Let’s take a closer look.

Attempt 1: Just copy the application and see what happens

The initial plan was simple: build the DHCP client application, configure its entry point and memory in the hypervisor, and try to boot it. We didn’t expect it to run flawlessly on the first attempt; the assumption was that it would at least reach the main function and then fail due to unassigned network peripherals. The idea was to fix such issues step by step with GDB. What we didn’t anticipate was that the first obstacles would come from the hypervisor itself rather than the application. But let’s start from the beginning, this is how we’ve done it.

To launch a Zephyr application inside CROSSCON, the hypervisor needs to know two things:

  1. Where execution should begin (the entry address).
  2. How the application’s memory is laid out (RAM and FLASH regions).

The entry point can be extracted from the Zephyr ELF file:

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readelf -aW zephyr.elf  | grep __start
  4942: 00045b15     0 FUNC    GLOBAL DEFAULT    2 __start

On ARM Cortex-M architectures, function addresses use the least significant bit to indicate Thumb mode. This means the actual entry address in the hypervisor’s configuration must be the extracted value with that bit cleared (hence the -1).

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(...)
.entry = 0x00045b14,
(...)

Next, the RAM and FLASH layout must match what Zephyr expects. These regions are described in the application’s devicetree, so the .regions structure in the hypervisor configuration needs to be updated accordingly (e.g., regions[0] for SRAM, regions[1] for FLASH).

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(...)
.regions =  (struct vm_mem_region[]) {
    {
        .base = 0x20020000, //SRAM1
        .size = 0x10000
    },
    {
        .base = 0x00040000,
        .size = 0x10000
    }
},
(...)

But after every boot, the hypervisor jumped to the fault exception handler during the virtual machine initialization:

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fault_exception_handler () at /workdir/bao-hypervisor/src/arch/armv8m/fault_exceptions.c:10
10          while (1) { };

…and the debugging with three context layers present (the hypervisor, Zephyr RTOS, and the application) was too complicated to continue with this path. As stated earlier, the hypervisor does not provide any feedback about a configuration mismatch. We needed good-known configuration, thus we did the following…

Attempt 2: Turning “Hello world” into the Wi-Fi application

Another approach was to start from a known working configuration demo and gradually adapt it. We used a simple Hello world application as a template and then added the target application piece by piece.

The first step was to enable the necessary device drivers in the Zephyr configuration, even if they were not immediately used. Doing this allowed us to verify correct device assignment and initialization before tackling the more complex DHCP application logic. The aim was simple, and it was all about “booting” anything.

In Zephyr, each application defines its configuration in a prj.conf file, which is a Kconfig fragment that enables drivers and features. These settings are merged with other defaults to produce the final build configuration. While the Hello world application could run with an empty prj.conf, the Wi-Fi demo required additional drivers, which were added incrementally to the configuration.

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CONFIG_NETWORKING=y
CONFIG_NET_IPV6=n
CONFIG_NET_IPV4=y
CONFIG_NET_ARP=y
CONFIG_NET_UDP=y
CONFIG_NET_DHCPV4=y
CONFIG_NET_DHCPV4_OPTION_CALLBACKS=y
CONFIG_DNS_RESOLVER=y

CONFIG_TEST_RANDOM_GENERATOR=y

CONFIG_INIT_STACKS=y

CONFIG_NET_MGMT=y
CONFIG_NET_MGMT_EVENT=y
CONFIG_NET_MGMT_EVENT_INFO=y

CONFIG_NET_LOG=y
CONFIG_LOG=y

CONFIG_SLIP_STATISTICS=n
CONFIG_NET_SHELL=y

CONFIG_WIFI=y

CONFIG_NET_L2_WIFI_MGMT=y

The first step of the new strategy was to simply copy those settings into Hello world’s prj.conf and build it. This was enough to trigger a build error:

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zephyr/zephyr-sdk-0.17.0/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/../../../../arm-zephyr-eabi/bin/ld.bfd: zephyr/zephyr_pre0.elf section `text' will not fit in region `FLASH'
zephyr/zephyr-sdk-0.17.0/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/../../../../arm-zephyr-eabi/bin/ld.bfd: region `FLASH' overflowed by 35820 bytes
collect2: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.

After the first step, the Wi-Fi application produced a flash memory overflow. The root cause was that the original DHCP demo was configured without the hypervisor’s memory limits, using upstream Zephyr with a larger allowed flash size. In contrast, the fork used for the Hello world template enforces stricter flash limits to fit the memory allocated to the virtual machine.

To reduce memory usage, we first disabled unnecessary features, such as CONFIG_NET_SHELL, which provides network commands that were not needed. This made it possible to build the application, but runtime exceptions persisted, indicating that some drivers were failing to initialize the hardware. The next step was to enable drivers in prj.conf incrementally, identifying and fixing the ones causing the issues.

The first configuration option - CONFIG_NETWORKING=y - was enough to cause a hypervisor exception. The question is why? After comparing configuration files from before and after enabling CONFIG_NETWORKING, some interesting dependencies that were automatically added to the configuration image showed up:

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1301a1505,1506
> CONFIG_ENTROPY_DEVICE_RANDOM_GENERATOR=y
> # CONFIG_XOSHIRO_RANDOM_GENERATOR is not set
1302a1508,1510
> CONFIG_CSPRNG_ENABLED=y
> CONFIG_HARDWARE_DEVICE_CS_GENERATOR=y
> # CONFIG_CTR_DRBG_CSPRNG_GENERATOR is not set

Zephyr RTOS networking module requires access to the random number generator (RNG), which was not initially available to the virtual machine.

Hardware access needs to be configured in the hypervisor config file. In CROSSCON, a virtual machine is granted access to a device by adding a corresponding entry to the devs field using a vm_dev_region structure:

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.dev_num = 4,
.devs =  (struct vm_dev_region[]) {
{
    /* Flexcomm Interface 2 (USART2) */
    .pa = 0x40088000,
    .va = 0x40088000,
    .size = 0x1000,
    .interrupt_num = 1,
    .interrupts = (irqid_t[]) {16+16}
},
{
    /* SYSCON + IOCON + PINT + SPINT */
    .pa = 0x40000000,
    .va = 0x40000000,
    .size = 0x5000,
},

(...)

The memory map of the board can be found in the board user manual. The address of the RNG that was found in the manual is shown below.

img

A quick look at the Zephyr RTOS device tree showed that the size of RNG’s memory region is 0x1000:

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 rng: rng@3a000 {
  compatible = "nxp,lpc-rng";
  reg = <0x3a000 0x1000>;
  status = "okay";
 };

Access was granted by modifying the previously mentioned hypervisor configuration:

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@@ -74,7 +74,7 @@ struct config config = {
                         .size = 0x10000
                     }
                 },
-                .dev_num = 4,
+                .dev_num = 5,
                 .devs =  (struct vm_dev_region[]) {
                     {
                         /* Flexcomm Interface 2 (USART2) */
@@ -102,6 +102,12 @@ struct config config = {
                         .va = 0x40020000,
                         .size = 0x1000,https://git.3mdeb.com/3mdeb/offers/pulls/200
                     },
+                    {
+                        /* RNG */
+                        .pa = 0x4003a000,
+                        .va = 0x4003a000,
+                        .size = 0x1000,
+                    },
                 },
                 .ipc_num = 1,
                 .ipcs = (struct ipc[]) {

This, however, did not initially work. The program terminated with an error:

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    at bao-hypervisor/src/arch/armv8m/mem.c:32
32                  ERROR("failed to register sau entry");

After discussing the issue with the CROSSCON Hypervisor maintainers, we discovered that the number of SAU entries for TrustZone had exceeded. Each vm_dev_region in the hypervisor configuration consumes one or more SAU entries, and the original setup had more regions than the hardware could handle.

The solution was to merge some of the vm_dev_region structures into larger contiguous regions, reducing the total number of SAU entries while still covering the same devices and memory areas:

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                         .size = 0x10000
                     }
                 },
-                .dev_num = 5,
+                .dev_num = 4,
                 .devs =  (struct vm_dev_region[]) {
                     {
                         /* Flexcomm Interface 2 (USART2) */
@@ -90,18 +90,12 @@ struct config config = {
                         .va = 0x40000000,
                         .size = 0x5000,
                     },
-                    {
-                        /* ANALOG */
+                    {
+                        /* ANALOG + POWER MGM  */
                         .pa = 0x40013000,
                         .va = 0x40013000,
-                        .size = 0x1000,
-                    },
-                    {
-                        /* POWER MGM */
-                        .pa = 0x40020000,
-                        .va = 0x40020000,
-                        .size = 0x1000,
-                    },
+                        .size = 0xE000,
+                    },
                     {

This adjustment brought the configuration within the SAU limit, allowing the virtual machine to access all required devices properly. Without this change, the hypervisor could not map all devices, which would have caused hardware access failures in the VM.

During testing, the DHCP application failed to run correctly, even after the previous configuration fixes. The root cause was a conflict on the UART used by the Wi-Fi module: the same UART had previously been assigned for serial communication between the virtual machine and the host PC, leading to crashes. Additionally, enabling CONFIG_NET_LOG and CONFIG_LOG triggered logging over that same UART, which exacerbated the problem.

The solution was straightforward: disable the conflicting options. After turning off CONFIG_NET_LOG and CONFIG_LOG, the modified Hello world application, now using the full prj.conf from the DHCP application, booted successfully. With this setup working correctly, it was finally time to run the DHCP application itself.

Back to the DHCP application

Unfortunately, running the DHCP application after the corrections in the previous chapter caused another jump to fault_exception_handler. A quick debugging with GDB pointed out a problem with memset the function:

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Breakpoint 1, z_early_memset (dst=0x20023690 <z_interrupt_stacks>, c=170, n=2048)
    at zephyr/kernel/init.c:197
197             (void) memset(dst, c, n);

(gdb) stepi
0x0005082a in memset ()
(gdb)
_exception_handler ()
    at bao-hypervisor/src/arch/armv8m/exceptions.S:156
156         b   fault_exception_handler

Further debugging allowed us to track the addresses that the memset was using:

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(gdb) p memset
$1 = {void *(void *, int, size_t)} 0x100015a6 <memset>
(gdb) p dst
$2 = (void *) 0x20023690 <z_interrupt_stacks>
(gdb) p c
$3 = 170
(gdb) p n
$4 = 2048

The addresses were correctly passed to the Zephyr RTOS Devicetree. The problem was elsewhere - the second entry in regions defines FLASH memory addresses available to the virtual machine:

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.regions =  (struct vm_mem_region[]) {
    {
        .base = 0x20020000, //SRAM1
        .size = 0x10000
    },
    {
        .base = 0x00040000,
        .size = 0x10000
    }
},

The address used by the memset was 0x0005082a, which lay outside the virtual machine’s assigned memory range. The issue was fixed by increasing the VM’s RAM allocation to 0x20000, ensuring that the memory accessed by the application fell within the allowed range.

With this updated configuration, no exceptions were thrown. This, however, was not the end of the problems.

The hypervisor refused to run code inside VM1 while VM0 was running correctly. Since the hypervisor executed successfully, yet only one of the VMs provided output, we suspected the issue might be related to the scheduler. The whole case of how we verified that is described later in this section; for now, let’s focus on the theory. The system uses the TrustZone system clock that generates periodic SysTick interrupts inside TrustZone. These interrupts trigger the hypervisor’s scheduler. This is a classical implementation of the Round Robin scheduling policy, which makes sure that every virtual machine gets its slice of the CPU time periodically. The scheduler’s dispatcher might be another problem here. Without it working correctly, the next-to-execute virtual machine context can be restored incorrectly.

First things first - a breakpoint inside the SysTick handler was set to verify that both the scheduling policy and the dispatcher are working correctly:

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175         mov r0, #SYSTICK_INT_N
(gdb) n
176         bl interrupts_handle
(gdb) p $r0
$9 = 15
(...)
interrupts_handle (int_id=15)
    at bao-hypervisor/src/core/interrupts.c:110
110             return HANDLED_BY_HYP;

After examining the ARMv8-M Architectural Reference Manual, it turned out that ID 15 corresponds to the SysTick interrupt. It means that the context switch between virtual machines was actually happening. A breakpoint just before switching to the virtual machine context was set to confirm this:

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Breakpoint 1, excep_return ()
    at bao-hypervisor/src/arch/armv8m/exceptions.S:188
188         bx lr
(gdb) si
main ()
    at bao-baremetal-guest/src/main.c:101
101         while(1) wfi();
(gdb) c
Continuing.
INFO: [stub (3333)] Xw:
INFO: [stub (3333)] Xc:

Breakpoint 1, excep_return ()
    at bao-hypervisor/src/arch/armv8m/exceptions.S:188
188         bx lr
(gdb) si
    at modules/hal/cmsis/CMSIS/Core/Include/cmsis_gcc.h:951
951       __ASM volatile ("cpsie i" : : : "memory");
(gdb) n
arch_cpu_idle ()
    at zephyr/arch/arm/core/cortex_m/cpu_idle.c:105
105             __ISB();
(gdb) n
idle (unused1=<optimized out>, unused2=<optimized out>, unused3=<optimized out>)
    at zephyr/kernel/idle.c:51
51                      (void) arch_irq_lock();
(gdb) n
75                      k_cpu_idle();

Code from Zephyr RTOS was being executed, which confirmed that the switch was happening. For some reason, however, Zephyr RTOS executed the idle task instead of the DHCP application’s task.

The problem was caused by a conflict in the UART interfaces configuration - the same UART was once again set up to be used for both the serial console and the Wi-Fi module, which caused initialization failure in the DHCP application’s task. This time, the logs from the DHCP application were needed. Therefore, the Devicetree was modified so that two different interfaces were used.

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--- a/boards/nxp/lpcxpresso55s69/lpcxpresso55s69_lpc55s69_cpu0_ns.dts
+++ b/boards/nxp/lpcxpresso55s69/lpcxpresso55s69_lpc55s69_cpu0_ns.dts
@@ -30,9 +30,9 @@
                zephyr,sram = &non_secure_ram;
                zephyr,flash = &flash0;
                zephyr,code-partition = &slot0_ns_partition;
-               zephyr,uart-mcumgr = &flexcomm2;
-               zephyr,console = &flexcomm2;
-               zephyr,shell-uart = &flexcomm2;
+               zephyr,uart-mcumgr = &flexcomm3;
+               zephyr,console = &flexcomm3;
+               zephyr,shell-uart = &flexcomm3;
                zephyr,entropy = &rng;
        };

@@ -84,6 +84,10 @@
        status = "okay";
 };

+&flexcomm3 {
+       status = "okay";
+};
+
 &flexcomm4 {
        status = "okay";
 };
--- a/boards/nxp/lpcxpresso55s69/lpcxpresso55s69.dtsi
+++ b/boards/nxp/lpcxpresso55s69/lpcxpresso55s69.dtsi
@@ -12,7 +12,7 @@
                led1 = &green_led;
                led2 = &blue_led;
                spi-8 = &hs_lspi;
-               usart-0 = &flexcomm2;
+               usart-0 = &flexcomm3;
        };

        leds {
@@ -104,7 +104,7 @@
        };
 };

-&flexcomm2 {
+&flexcomm3 {
        compatible = "nxp,lpc-usart";
        current-speed = <115200>;
 };
@@ -188,6 +188,11 @@ mikrobus_spi: &hs_lspi {
        pinctrl-names = "default";
 };

+&flexcomm3 {
+       pinctrl-0 = <&pinmux_flexcomm3_usart>;
+       pinctrl-names = "default";
+};
+
 &flexcomm4 {
        pinctrl-0 = <&pinmux_flexcomm4_i2c>;
        pinctrl-names = "default";
--- a/boards/nxp/lpcxpresso55s69/lpcxpresso55s69-pinctrl.dtsi
+++ b/boards/nxp/lpcxpresso55s69/lpcxpresso55s69-pinctrl.dtsi
@@ -27,6 +27,14 @@
                };
        };

+       pinmux_flexcomm3_usart: pinmux_flexcomm3_usart {
+               group0 {
+                       pinmux = <FC3_TXD_SCL_MISO_WS_PIO0_2>,
+                               <FC3_RXD_SDA_MOSI_DATA_PIO0_3>;
+                       slew-rate = "standard";
+               };
+       };
+
        pinmux_flexcomm4_i2c: pinmux_flexcomm4_i2c {
                group0 {
                        pinmux = <FC4_TXD_SCL_MISO_WS_PIO1_20>,

Now the main thread was executed. However, the Wi-Fi module was not being correctly initialized:

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[00:00:00.000,000] <inf> wifi_esp_at: DT has external_reset
[00:00:00.000,000] <inf> wifi_esp_at: Waiting for interface to come up by itself...
[00:00:03.000,000] <inf> wifi_esp_at: Result: -11
[00:00:03.000,000] <inf> wifi_esp_at: ESP_AT: sending RST CMD
[00:00:06.000,000] <inf> wifi_esp_at: ESP_AT: sending RST CMD
[00:00:09.000,000] <inf> wifi_esp_at: ESP_AT: sending RST CMD
[00:00:12.001,000] <err> wifi_esp_at: Failed to reset device: -116
*** Booting Zephyr OS build v4.1.0-1219-g584f2f86f905 ***
[00:00:12.001,000] <inf> MAIN: Hello in WiFi App!
[00:00:12.001,000] <inf> MAIN: Connecting to Wi-Fi network rpi3-hotspot...
[00:00:12.001,000] <err> MAIN: Failed to connect to Wi-Fi network: -115
[00:00:12.001,000] <inf> MAIN: Run dhcpv4 client
[00:00:12.001,000] <inf> MAIN: Start on mikroe_wifi_bt_click: index=1          ```

Further diagnosis showed an interesting bug: The elapsed time within Zephyr RTOS, was 16 times slower than real time:

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[2025-04-29 21:17:07.740] *** Booting Zephyr OS build v4.1.0-1220-gf352f026f154 ***
[2025-04-29 21:17:07.740] Hello World from Zephyr VM running on CROSSCON HV!
[2025-04-29 21:17:07.740] Uptime: 1 ms
[2025-04-29 21:17:15.734] Uptime: 1001 ms
[2025-04-29 21:17:23.730] Uptime: 2001 ms
[2025-04-29 21:17:31.725] Uptime: 3001 ms
[2025-04-29 21:17:39.720] Uptime: 4002 ms
[2025-04-29 21:17:47.716] Uptime: 5002 ms
[2025-04-29 21:17:55.712] Uptime: 6002 ms
[2025-04-29 21:18:03.708] Uptime: 7002 ms
[2025-04-29 21:18:11.703] Uptime: 8002 ms
[2025-04-29 21:18:19.699] Uptime: 9003 ms
[2025-04-29 21:18:27.694] Timer test end

The timer was divided by the hypervisor depending on the number of virtual machines (by two in this case). Additionally, within Zephyr RTOS it ran 8 times slower. The CROSSCON Hypervisor issue was fixed by its maintainers. Zephyr’s time division was easy to correct with a proper system timer configuration, though we did not investigate why the slowdown was exactly by this factor.

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# must be equal to the PLAT_TIMER_FREQ as set by the CROSSCON HV
CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC=12000000

The final problem was again related to UART - the RX callback was not being triggered. It was suggested by the hypervisor maintainers that instead of looking for the solution within the Bao Hypervisor, it is better to switch to the CROSSCON Hypervisor, where the issue no longer appeared. The CROSSCON hypervisor configuration followed a slightly different format. It was modified to use a single virtual machine with the Zephyr RTOS DHCP demo application.

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#include <config.h>

struct vm_config zephyr = {
    .image = VM_IMAGE_LOADED(0x00040000, 0x00040000, 0xF000),
    .entry = @@ZEPHYR_VM_ENTRY@@,
    .platform = {
        .cpu_num = 1,
        .region_num = 2,
        .regions =  (struct vm_mem_region[]) {
            {
                .base = 0x20020000, //SRAM1
                .size = 0x10000
            },
            {
                .base = 0x00040000,
                .size = 0x18000
            }
        },
        .dev_num = 4,
        .devs =  (struct vm_dev_region[]) {
            {
                /* Flexcomm Interface 2 (USART2) */
                /* AND */
                /* Flexcomm Interface 3 (USART3) */
                .pa = 0x40088000,
                .va = 0x40088000,
                .size = 0x2000,
                .interrupt_num = 2,
                .interrupts = (irqid_t[]) {16+16, 17+16}
            },
            {
                /* SYSCON + IOCON + PINT + SPINT */
                .pa = 0x40000000,
                .va = 0x40000000,
                .size = 0x5000,
            },
            {
                /* ANALOG + POWER MGM  */
                .pa = 0x40013000,
                .va = 0x40013000,
                .size = 0xE000,
            },
            {
                /* RNG */
                .pa = 0x4003a000,
                .va = 0x4003a000,
                .size = 0x1000,
            },
        },
        .ipc_num = 1,
        .ipcs = (struct ipc[]) {
            {
                .base = 0x20017000,
                .size = 0x1000,
                .shmem_id = 0,
                .interrupt_num = 1,
                .interrupts = (irqid_t[]) {79}
            }
        },
    }
};

struct config config = {

    CONFIG_HEADER
    .shmemlist_size = 1,
    .shmemlist = (struct shmem[]) {
        [0] = {.base = 0x20017000, .size = 0x1000,},
    },
    .vmlist_size = 1,
    .vmlist = (struct vm_config*[]) {
        &zephyr
    }
};

This was the final step required to get the DHCP application to work. The Wi-Fi module was initialized correctly, and the board managed to establish a connection with the Wi-Fi access point:

img

Summary

Running a Zephyr application on top of the CROSSCON Hypervisor is a task that comes with many challenges. Despite having a working application, many issues arose along the way, from enabling devices used internally by libraries to fixing hypervisor bugs.

For any questions or feedback, feel free to contact us at contact@3mdeb.com or hop on our community channels:

Mateusz Kusiak
Former System Software Development Engineer at Intel, currently Junior Embedded Systems Developer at 3mdeb. Privately, a tinkering enthusiast.

Daniil Klimuk
Programming, electronics and cycling nerd, bookworm and very passionate in learning. Left his own country at seventeen years old for studying and working abroad, and still searching for a place to settle. Big critic of fatalism and a fan of what-you-are-is-what-you-do way of thinking. In professional life tries to be as pedantic as possible, believes that nothing is perfect and nobody is perfect and every solution should be questioned and evaluated. Likes to solve complex problems, even if it implies a lot of digging before stating the final solution. States that developing skills in different fields is important as well as perfecting a one field, because everything has its intersections and sometimes it is crucial to investigate something from a different angle. Most of the time a workaholic, but sometimes a bit lazy. Not always punctual and often unconsciously altruistic.

Paweł Langowski
Junior Embedded Systems Engineer. On a mission to understand how things work deep inside.

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