boot.sh

#!/bin/bash

set -e

this_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"

qemu_prefix="/usr/local/"

arch="$1"
executable="$2"

if [ -z "$arch" ] || [ -z "$executable" ]; then
    echo "USAGE: $0 ARCH EXECUTABLE_FILE" >&2
    exit 1
fi

target_dir="$(dirname "$executable")"
kernel_dir="${target_dir/-uefi/-tartan}"

case "$arch" in
    i686)
        boot_filename="BOOTIA32.EFI"
        qemu_suffix="i386"
        efi_code="edk2-i386-code.fd"
        efi_vars="edk2-i386-vars.fd"
        qemu_args=()
        ;;
    x86_64)
        boot_filename="BOOTX64.EFI"
        qemu_suffix="x86_64"
        efi_code="edk2-x86_64-code.fd"
        efi_vars="edk2-i386-vars.fd"  # Shared with 32-bit
        qemu_args=()
        ;;
    arm)
        # UEFI expects the PE machine type to be 0x01c2 (Thumb), but LLVM only emits
        # 0x01c4 (Arm "NT", whatever that means) for 32-bit Arm architectures, so we have
        # to override it with a Python script.
        pe_machine_type_override="0x01c2"
        boot_filename="BOOTARM.EFI"
        qemu_suffix="arm"
        efi_code="edk2-arm-code.fd"
        efi_vars="edk2-arm-vars.fd"
        qemu_args=(
            -machine virt
            -cpu cortex-a15
        )
        ;;
    aarch64)
        boot_filename="BOOTAA64.EFI"
        qemu_suffix="aarch64"
        efi_code="edk2-aarch64-code.fd"
        efi_vars="edk2-arm-vars.fd"  # Shared with 32-bit
        qemu_args=(
            -machine virt
            -cpu cortex-a57
        )
        ;;
    *)
        echo "Unknown architecture '$arch'. Cannot boot with UEFI." >&2
        exit 1
esac

# Prepare directory for virtual FAT boot image
boot_dir="$target_dir/boot-fs"
mkdir -p "$boot_dir/EFI/BOOT"
cp "$executable" "$boot_dir/EFI/BOOT/$boot_filename"
cp "$kernel_dir/tartan-kernel" "$boot_dir/EFI/BOOT/TARTAN.ELF"

# Override the PE machine type if necessary
if [ -n "$pe_machine_type_override" ]; then
    echo "Setting PE machine type to $pe_machine_type_override"
    "$this_dir"/set-pe-machine-type.py \
        "$boot_dir/EFI/BOOT/$boot_filename" \
        "$pe_machine_type_override"
fi

# Copy EFI var file to allow writes (required by EDK2 on ARM)
cp "$qemu_prefix"/share/qemu/"$efi_vars" "$target_dir"/"$efi_vars"

cat >&2 <<EOF
=============================
Starting QEMU in console mode
 > To exit, press Ctrl+a, x
 > For more, press Ctrl+a, h
=============================
EOF
qemu-system-"$qemu_suffix" \
    "${qemu_args[@]}" \
    -drive if=pflash,format=raw,unit=0,file="$qemu_prefix"/share/qemu/"$efi_code",readonly=on \
    -drive if=pflash,format=raw,unit=1,file="$target_dir"/"$efi_vars" \
    -drive if=virtio,id=stick,format=raw,file=fat:rw:"$boot_dir" \
    -nographic \
    -gdb tcp::1234 \
    -net none