2. Configure and Build BitVisor

Select compile-time options, write runtime configuration (defconfig), and build

Compile-time Configuration (Kconfig)

Run the following from the source directory:

make config

Recommended options for getting started:

- 64
- CPU_MMU_SPT_1
- CPU_MMU_SPT_USE_PAE
- DBGSH
- ACPI_DSDT
- DISABLE_SLEEP
- ENABLE_ASSERT
- NET_DRIVER
  - NET_PRO1000  (Intel NIC)
  - NET_RE       (Realtek NIC)
  - NET_BNX      (Broadcom NIC)
  - NET_AQ       (Aquantia NIC)
- NET_VIRTIO_NET (expose NIC to guest as virtio — recommended)
- ACPI_TIME_SOURCE
- TCG_BIOS
- BACKTRACE
- IP
- THREAD_1CPU
- ACPI_IGNORE_ERROR
- DISABLE_VTD
- DMAR_PASS_THROUGH

Compiler warnings from external or unmaintained research code can be safely ignored.

Runtime Configuration (defconfig)

Copy the template and edit it:

cp defconfig.tmpl defconfig

The defconfig file uses plain C struct initialization syntax. See include/share/config.h for the full structure definition.

Minimal network and syslog configuration

struct config_data config = {
    .vmm = {
        .tty_mac_address = {
            0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF  /* MAC of syslog receiver */
        },
        .tty_syslog = {
            .enable     = 1,
            .src_ipaddr = { 192, 168, 0, 7 },    /* BitVisor source IP */
            .dst_ipaddr = { 192, 168, 0, 1 },    /* syslog receiver IP */
        },
        .driver = {
            .pci = "driver=pro1000, net=ippass, tty=1, virtio=1",
        },
    },
    .ip = {
        .use_dhcp = 0,
        .ipaddr   = { 192, 168, 0, 7 },
        .netmask  = { 255, 255, 255, 0 },
        .gateway  = { 192, 168, 0, 1 },
    },
};

`net=` option reference

Value	Behavior
`net=pass`	No IP stack; traffic goes to guest only
`net=ip`	BitVisor runs IP stack; traffic does not reach the guest
`net=ippass`	BitVisor and guest both receive traffic
`net=ippassfilter`	Separates traffic when possible
`net=ippassfilter2`	Like ippassfilter with spurious interrupt workaround (recommended for `bnx`, `re`, `aq`)

pro1000 uses MSI interrupts and works fine with net=ippass. bnx, re, and aq use pin interrupts, so ippassfilter2 is recommended.

NIC driver name reference

NIC	`driver=` value
Intel	`pro1000`
Broadcom	`bnx`
Realtek	`re`
Aquantia	`aq`

Build the Hypervisor

make

On success, bitvisor.elf is generated in the source root.

Build the UEFI Loader

cd boot/uefi-loader
make

On success, boot/uefi-loader/loadvmm.efi is generated.

Cross-compiling for AArch64 (Experimental)

To cross-compile on an x86_64 host:

# Hypervisor core
CROSS_COMPILE=aarch64-none-linux-gnu- ARCH=aarch64 make

# UEFI loader
cd boot/uefi-loader
CROSS_COMPILE=aarch64-none-linux-gnu- ARCH=aarch64 make

Adjust CROSS_COMPILE to match your toolchain prefix. Verify the output architecture:

file bitvisor.elf
# → ELF 64-bit LSB executable, ARM aarch64, ...

file boot/uefi-loader/loadvmm.efi
# → PE32+ executable (DLL) (EFI application) Aarch64, ...