Configuring two FreeRTOS VMs

[Everaldo-Gomes]

Hi,

I'm trying to configure two FreeRTOS VMS.
Using the demo Dual-guest Linux+FreeRTOS, I removed the Linux and put another FreeRTOS in its place.

Using the following configuration file I keep getting the error: BAO ERROR: no handler for abort ec = 0x20.

In the .vmlist the first VM, is the default FreeRTOS config. The problem is when trying to configure the second FreeRTOS (freertos_image_2).

I can't identify what is wrong.

Platform: Raspberry Pi 4b
Demo: Dual-guest Linux+FreeRTOS

#include <config.h>

VM_IMAGE(freertos_image, XSTR(BAO_DEMOS_WRKDIR_IMGS/freertos.bin)); 
VM_IMAGE(freertos_image_2, XSTR(BAO_DEMOS_WRKDIR_IMGS/freertos_2.bin));

struct config config =
{
    CONFIG_HEADER

    .shmemlist_size = 1,
    .shmemlist = (struct shmem[])
    {
        [0] = { .size = 0x00010000, }
    },
    
    .vmlist_size = 2,
    .vmlist =
    {
        { 
            .image =
            {
                .base_addr = 0x0,
                .load_addr = VM_IMAGE_OFFSET(freertos_image),
                .size = VM_IMAGE_SIZE(freertos_image)
            },

            .entry = 0x0,
            .colors = 0x0F0F,

            .platform =
            {
                .cpu_num = 1,
                
                .region_num = 1,
                .regions =  (struct vm_mem_region[])
                {
                    {
                        .base = 0x0,
                        .size = 0x8000000 
                    }
                },

                .ipc_num = 1,
                .ipcs = (struct ipc[])
                {
                    {
                        .base = 0x70000000,
                        .size = 0x00010000,
                        .shmem_id = 0,
                        .interrupt_num = 1,
                        .interrupts = (irqid_t[]) {52}
                    }
                },

                .dev_num = 2,
                .devs =  (struct vm_dev_region[])
                {
                    {   
                        /* UART1 */
                        .pa = 0xfe215000,
                        .va = 0xff000000,
                        .size = 0x1000,
                        .interrupt_num = 1,
                        .interrupts = (irqid_t[]) {125}
                    },
                    {   
                        /* Arch timer interrupt */
                        .interrupt_num = 1,
                        .interrupts = (irqid_t[]) {27}
                    }
                },
                .arch =
                {
                    .gic =
                    {
                        .gicd_addr = 0xF9010000,
                        .gicc_addr = 0xF9020000,
                    }
                }
            },
        },
      
        //--------------------------------------------------------------
        // Trying to add the second FreeRTOS image
        //--------------------------------------------------------------

        {
            .image =
            {
                .base_addr = 0x20000000,
                .load_addr = VM_IMAGE_OFFSET(freertos_image_2),
                .size = VM_IMAGE_SIZE(freertos_image_2)
            },

            .entry = 0x20000000,
            .colors = 0xF0F0,

            .platform =
            {
                .cpu_num = 1,
                
                .region_num = 1,
                .regions =  (struct vm_mem_region[])
                {
                    {
                        .base = 0x20000000,
                        .size = 0x40000000,
                    }
                },

                .ipc_num = 1,
                .ipcs = (struct ipc[])
                {
                    {
                        .base = 0xf0000000,
                        .size = 0x00010000,
                        .shmem_id = 0,
                        .interrupt_num = 1,
                        .interrupts = (irqid_t[]) {52}
                    }
                },

                .dev_num = 2,
                .devs =  (struct vm_dev_region[])
                {
                    {
                        /* GENET */
                        .pa = 0xfd580000,
                        .va = 0xfd580000,
                        .size = 0x10000,
                        .interrupt_num = 2,
                        .interrupts = (irqid_t[]) {189, 190}  
                    },
                    {   
                        /* Arch timer interrupt */
                        .interrupt_num = 1,
                        .interrupts = (irqid_t[]) {27}                         
                    }
                },

                .arch =
                {
                    .gic =
                    {
                        .gicd_addr = 0xff841000,
                        .gicc_addr = 0xff842000,
                    }
                }
            },
        },
    },
};

[josecm]

With that exception code, it seems the second FreeRTOS instance is trying to execute an instruction from an address that does not exist for that VM. I noticed you kept the original base address (0x20000000) of the original Linux VM for the second FreeRTOS instance. Did you recompile the second FreeRTOS image to that base address? If not, you either need to do it or change the base addresses of the second VM to 0x0.

[josecm]

Also, the interrupt controller and peripheral addresses of the second VM need to be adapted to match what the FreeRTOS guest is expecting!

[Everaldo-Gomes]

It's working! Thank you.

In this file, we also specify the number of CPUs. Is there a way to define for example that the first guest will use CPU 0 and the second guest CPU 1?