# Copyright 2018 The Hafnium Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import("//build/toolchain/embedded.gni")
import("//build/toolchain/platform.gni")

# Build image, link to an ELF file then convert to plain binary.
template("image_binary") {
  assert(defined(invoker.image_name),
         "image_binary() must specify an \"image_name\" value")

  output_root = ""
  if (defined(invoker.output_path)) {
    output_root += "${invoker.output_path}/"
  }
  output_root += invoker.image_name

  file_root = "${root_out_dir}/${output_root}"
  elf_file = "${file_root}.elf"
  bin_file = "${file_root}.bin"

  elf_target = "${target_name}__elf"
  checked_elf_target = "${target_name}__checked_elf"

  # Link objects together
  executable(elf_target) {
    forward_variables_from(invoker,
                           [
                             "cflags",
                             "cflags_c",
                             "defines",
                             "deps",
                             "include_dirs",
                             "public_configs",
                             "public_deps",
                             "sources",
                             "testonly",
                           ])
    output_name = "${output_root}.elf"
    inputs = [
      rebase_path("//build/image/image.ld"),
    ]
    ldflags = [
      "-T",
      rebase_path("//build/image/image.ld"),
    ]
    visibility = [
      ":${checked_elf_target}",
      ":${invoker.target_name}",
    ]
  }

  # Analyze the generated ELF file and check that assembly-level fixes, e.g.
  # for CPU errata, have been properly applied.
  action(checked_elf_target) {
    forward_variables_from(invoker, [ "testonly" ])
    stamp_file = elf_file + "_check.stamp"

    script = "//build/image/check_elf.py"
    deps = [
      ":${elf_target}",
    ]
    args = [
      rebase_path(elf_file),
      rebase_path(stamp_file),
      "--max-image-size",
      "$plat_max_image_size",
    ]
    outputs = [
      stamp_file,
    ]
    visibility = [ ":${invoker.target_name}" ]
  }

  action(target_name) {
    forward_variables_from(invoker, [ "testonly" ])

    script = "//build/image/convert_to_binary.py"

    if (defined(invoker.check_binary) && invoker.check_binary == true) {
      deps = [
        ":${checked_elf_target}",
      ]
    } else {
      deps = [
        ":${elf_target}",
      ]
    }
    args = [
      "--input",
      rebase_path(elf_file),
      "--output",
      rebase_path(bin_file),
    ]
    outputs = [
      bin_file,
    ]
  }
}

# Helper to build a hypervisor image
template("hypervisor") {
  image_binary(target_name) {
    forward_variables_from(invoker,
                           [
                             "cflags",
                             "cflags_c",
                             "defines",
                             "deps",
                             "public_deps",
                             "sources",
                             "testonly",
                           ])
    image_name = target_name

    # Perform checks on the generated binary to prevent regressing on some
    # classes of bugs, typically CPU erratas.
    check_binary = true
  }
}

# Helper to build a virtual machine kernel
template("vm_kernel") {
  image_binary(target_name) {
    forward_variables_from(invoker,
                           [
                             "cflags",
                             "cflags_c",
                             "defines",
                             "deps",
                             "include_dirs",
                             "public_configs",
                             "public_deps",
                             "sources",
                             "testonly",
                           ])
    output_path = rebase_path(".", root_out_dir, target_out_dir)
    image_name = target_name
  }
}

# Build the initial RAM disk for the Linux VM.
template("linux_initrd") {
  initrd_base = "${target_out_dir}/${target_name}/initrd"
  initrd_file = "${initrd_base}.img"
  initrd_staging = "${initrd_base}"

  copy("${target_name}__staging") {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "sources",
                             "deps",
                           ])
    outputs = [
      "${initrd_staging}/{{source_file_part}}",
    ]
  }

  action(target_name) {
    forward_variables_from(invoker, [ "testonly" ])
    script = "//build/image/generate_linux_initrd.py"
    args = [
      "--staging",
      rebase_path(initrd_staging),
      "--output",
      rebase_path(initrd_file),
    ]
    deps = [
      ":${target_name}__staging",
    ]
    outputs = [
      initrd_file,
    ]
  }
}

template("device_tree") {
  action(target_name) {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "deps",
                           ])
    script = "//build/image/dtc.py"

    sources = [
      invoker.source,
    ]
    outputs = [
      invoker.output,
    ]
    args = [
      "compile",
      "-i",
      rebase_path(sources[0]),
      "-o",
      rebase_path(outputs[0]),
    ]
  }
}

template("fdt_overlay") {
  action(target_name) {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "deps",
                           ])
    script = "//build/image/dtc.py"

    sources = [
      invoker.base,
      invoker.overlay,
    ]
    outputs = [
      invoker.output,
    ]
    args = [
      "overlay",
      rebase_path(outputs[0]),
      rebase_path(sources[0]),
      rebase_path(sources[1]),
    ]
  }
}

template("incbin") {
  source_set(target_name) {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "deps",
                           ])

    sources = [
      "//build/image/incbin.S",
    ]
    inputs = invoker.sources
    defines = [
      "SECTION_NAME=" + invoker.section,
      "FILE_PATH=\"" + rebase_path(inputs[0]) + "\"",
    ]
  }
}

template("incbin_target") {
  incbin(target_name) {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "deps",
                             "section",
                           ])
    target_outputs = get_target_outputs(invoker.target)
    target_file = target_outputs[0]
    sources = [
      target_file,
    ]
    deps = [
      invoker.target,
    ]
  }
}

# Build the initial RAM disk for the hypervisor.
template("initrd") {
  base_out_dir = "${target_out_dir}/${target_name}"
  manifest_target = "${target_name}__manifest"
  manifest_file = "${base_out_dir}/manifest.dtb"

  # Check if the invoker specified an overlay for the manifest.
  if (defined(invoker.manifest_overlay) && invoker.manifest_overlay != "") {
    manifest_base_target = "${target_name}__manifest_base"
    manifest_base_file = "${base_out_dir}/manifest_base.dtb"
    manifest_overlay_target = "${target_name}__manifest_overlay"
    manifest_overlay_file = "${base_out_dir}/manifest_overlay.dtbo"

    # Compile the base manifest.
    device_tree(manifest_base_target) {
      source = invoker.manifest
      output = manifest_base_file
    }

    # Compile the manifest overlay.
    device_tree(manifest_overlay_target) {
      source = invoker.manifest_overlay
      output = manifest_overlay_file
    }

    # Merge the base manifest and the overlay, producing the final manifest.
    fdt_overlay(manifest_target) {
      base = manifest_base_file
      overlay = manifest_overlay_file
      output = manifest_file
      deps = [
        ":$manifest_base_target",
        ":$manifest_overlay_target",
      ]
    }
  } else {
    # No overlay specified. Compile the manifest to DTB.
    device_tree(manifest_target) {
      source = invoker.manifest
      output = manifest_file
    }
  }

  action(target_name) {
    forward_variables_from(invoker, [ "testonly" ])
    script = "//build/image/generate_initrd.py"

    initrd_file = "${base_out_dir}/initrd.img"
    initrd_staging = "${base_out_dir}/initrd"

    deps = [
      ":${manifest_target}",
    ]
    args = [
      "--staging",
      rebase_path(initrd_staging),
      "--output",
      rebase_path(initrd_file),
      "--file",
      "manifest.dtb",
      rebase_path(manifest_file),
    ]

    if (defined(invoker.primary_vm)) {
      # Cannot get target outputs here as they are defined in a different file.
      primary_vm_image =
          get_label_info(invoker.primary_vm, "target_out_dir") + "/" +
          get_label_info(invoker.primary_vm, "name") + ".bin"

      deps += [ invoker.primary_vm ]
      args += [
        "--file",
        invoker.primary_name,
        rebase_path(primary_vm_image),
      ]

      if (defined(invoker.primary_initrd)) {
        deps += [ invoker.primary_initrd ]
        primary_initrd_outputs = get_target_outputs(invoker.primary_initrd)
        args += [
          "--file",
          "initrd.img",
          rebase_path(primary_initrd_outputs[0]),
        ]
      }
    }

    # Add the info about the secondary VMs. The information about the VMs is
    # encoded in lists with the following elements:
    #
    #    1. File name for the VM image.
    #    2. Build target for the VM.
    if (defined(invoker.secondary_vms)) {
      foreach(vm, invoker.secondary_vms) {
        deps += [ vm[1] ]
        args += [
          "--file",
          vm[0],
          rebase_path(get_label_info(vm[1], "target_out_dir") + "/" +
                      get_label_info(vm[1], "name") + ".bin"),
        ]
      }
    }

    outputs = [
      initrd_file,
    ]
  }
}