1// Copyright (C) 2021 The Android Open Source Project
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package filesystem
16
17import (
18	"fmt"
19	"strconv"
20	"strings"
21
22	"github.com/google/blueprint"
23	"github.com/google/blueprint/proptools"
24
25	"android/soong/android"
26)
27
28func init() {
29	android.RegisterModuleType("bootimg", bootimgFactory)
30}
31
32type bootimg struct {
33	android.ModuleBase
34
35	properties bootimgProperties
36
37	output     android.OutputPath
38	installDir android.InstallPath
39}
40
41type bootimgProperties struct {
42	// Set the name of the output. Defaults to <module_name>.img.
43	Stem *string
44
45	// Path to the linux kernel prebuilt file
46	Kernel_prebuilt *string `android:"arch_variant,path"`
47
48	// Filesystem module that is used as ramdisk
49	Ramdisk_module *string
50
51	// Path to the device tree blob (DTB) prebuilt file to add to this boot image
52	Dtb_prebuilt *string `android:"arch_variant,path"`
53
54	// Header version number. Must be set to one of the version numbers that are currently
55	// supported. Refer to
56	// https://source.android.com/devices/bootloader/boot-image-header
57	Header_version *string
58
59	// Determines if this image is for the vendor_boot partition. Default is false. Refer to
60	// https://source.android.com/devices/bootloader/partitions/vendor-boot-partitions
61	Vendor_boot *bool
62
63	// Optional kernel commandline
64	Cmdline *string `android:"arch_variant"`
65
66	// File that contains bootconfig parameters. This can be set only when `vendor_boot` is true
67	// and `header_version` is greater than or equal to 4.
68	Bootconfig *string `android:"arch_variant,path"`
69
70	// When set to true, sign the image with avbtool. Default is false.
71	Use_avb *bool
72
73	// Name of the partition stored in vbmeta desc. Defaults to the name of this module.
74	Partition_name *string
75
76	// Path to the private key that avbtool will use to sign this filesystem image.
77	// TODO(jiyong): allow apex_key to be specified here
78	Avb_private_key *string `android:"path"`
79
80	// Hash and signing algorithm for avbtool. Default is SHA256_RSA4096.
81	Avb_algorithm *string
82}
83
84// bootimg is the image for the boot partition. It consists of header, kernel, ramdisk, and dtb.
85func bootimgFactory() android.Module {
86	module := &bootimg{}
87	module.AddProperties(&module.properties)
88	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibFirst)
89	return module
90}
91
92type bootimgDep struct {
93	blueprint.BaseDependencyTag
94	kind string
95}
96
97var bootimgRamdiskDep = bootimgDep{kind: "ramdisk"}
98
99func (b *bootimg) DepsMutator(ctx android.BottomUpMutatorContext) {
100	ramdisk := proptools.String(b.properties.Ramdisk_module)
101	if ramdisk != "" {
102		ctx.AddDependency(ctx.Module(), bootimgRamdiskDep, ramdisk)
103	}
104}
105
106func (b *bootimg) installFileName() string {
107	return proptools.StringDefault(b.properties.Stem, b.BaseModuleName()+".img")
108}
109
110func (b *bootimg) partitionName() string {
111	return proptools.StringDefault(b.properties.Partition_name, b.BaseModuleName())
112}
113
114func (b *bootimg) GenerateAndroidBuildActions(ctx android.ModuleContext) {
115	vendor := proptools.Bool(b.properties.Vendor_boot)
116	unsignedOutput := b.buildBootImage(ctx, vendor)
117
118	if proptools.Bool(b.properties.Use_avb) {
119		b.output = b.signImage(ctx, unsignedOutput)
120	} else {
121		b.output = unsignedOutput
122	}
123
124	b.installDir = android.PathForModuleInstall(ctx, "etc")
125	ctx.InstallFile(b.installDir, b.installFileName(), b.output)
126}
127
128func (b *bootimg) buildBootImage(ctx android.ModuleContext, vendor bool) android.OutputPath {
129	output := android.PathForModuleOut(ctx, "unsigned", b.installFileName()).OutputPath
130
131	builder := android.NewRuleBuilder(pctx, ctx)
132	cmd := builder.Command().BuiltTool("mkbootimg")
133
134	kernel := proptools.String(b.properties.Kernel_prebuilt)
135	if vendor && kernel != "" {
136		ctx.PropertyErrorf("kernel_prebuilt", "vendor_boot partition can't have kernel")
137		return output
138	}
139	if !vendor && kernel == "" {
140		ctx.PropertyErrorf("kernel_prebuilt", "boot partition must have kernel")
141		return output
142	}
143	if kernel != "" {
144		cmd.FlagWithInput("--kernel ", android.PathForModuleSrc(ctx, kernel))
145	}
146
147	dtbName := proptools.String(b.properties.Dtb_prebuilt)
148	if dtbName == "" {
149		ctx.PropertyErrorf("dtb_prebuilt", "must be set")
150		return output
151	}
152	dtb := android.PathForModuleSrc(ctx, dtbName)
153	cmd.FlagWithInput("--dtb ", dtb)
154
155	cmdline := proptools.String(b.properties.Cmdline)
156	if cmdline != "" {
157		flag := "--cmdline "
158		if vendor {
159			flag = "--vendor_cmdline "
160		}
161		cmd.FlagWithArg(flag, proptools.ShellEscapeIncludingSpaces(cmdline))
162	}
163
164	headerVersion := proptools.String(b.properties.Header_version)
165	if headerVersion == "" {
166		ctx.PropertyErrorf("header_version", "must be set")
167		return output
168	}
169	verNum, err := strconv.Atoi(headerVersion)
170	if err != nil {
171		ctx.PropertyErrorf("header_version", "%q is not a number", headerVersion)
172		return output
173	}
174	if verNum < 3 {
175		ctx.PropertyErrorf("header_version", "must be 3 or higher for vendor_boot")
176		return output
177	}
178	cmd.FlagWithArg("--header_version ", headerVersion)
179
180	ramdiskName := proptools.String(b.properties.Ramdisk_module)
181	if ramdiskName == "" {
182		ctx.PropertyErrorf("ramdisk_module", "must be set")
183		return output
184	}
185	ramdisk := ctx.GetDirectDepWithTag(ramdiskName, bootimgRamdiskDep)
186	if filesystem, ok := ramdisk.(*filesystem); ok {
187		flag := "--ramdisk "
188		if vendor {
189			flag = "--vendor_ramdisk "
190		}
191		cmd.FlagWithInput(flag, filesystem.OutputPath())
192	} else {
193		ctx.PropertyErrorf("ramdisk", "%q is not android_filesystem module", ramdisk.Name())
194		return output
195	}
196
197	bootconfig := proptools.String(b.properties.Bootconfig)
198	if bootconfig != "" {
199		if !vendor {
200			ctx.PropertyErrorf("bootconfig", "requires vendor_boot: true")
201			return output
202		}
203		if verNum < 4 {
204			ctx.PropertyErrorf("bootconfig", "requires header_version: 4 or later")
205			return output
206		}
207		cmd.FlagWithInput("--vendor_bootconfig ", android.PathForModuleSrc(ctx, bootconfig))
208	}
209
210	flag := "--output "
211	if vendor {
212		flag = "--vendor_boot "
213	}
214	cmd.FlagWithOutput(flag, output)
215
216	builder.Build("build_bootimg", fmt.Sprintf("Creating %s", b.BaseModuleName()))
217	return output
218}
219
220func (b *bootimg) signImage(ctx android.ModuleContext, unsignedImage android.OutputPath) android.OutputPath {
221	propFile, toolDeps := b.buildPropFile(ctx)
222
223	output := android.PathForModuleOut(ctx, b.installFileName()).OutputPath
224	builder := android.NewRuleBuilder(pctx, ctx)
225	builder.Command().Text("cp").Input(unsignedImage).Output(output)
226	builder.Command().BuiltTool("verity_utils").
227		Input(propFile).
228		Implicits(toolDeps).
229		Output(output)
230
231	builder.Build("sign_bootimg", fmt.Sprintf("Signing %s", b.BaseModuleName()))
232	return output
233}
234
235func (b *bootimg) buildPropFile(ctx android.ModuleContext) (propFile android.OutputPath, toolDeps android.Paths) {
236	var sb strings.Builder
237	var deps android.Paths
238	addStr := func(name string, value string) {
239		fmt.Fprintf(&sb, "%s=%s\n", name, value)
240	}
241	addPath := func(name string, path android.Path) {
242		addStr(name, path.String())
243		deps = append(deps, path)
244	}
245
246	addStr("avb_hash_enable", "true")
247	addPath("avb_avbtool", ctx.Config().HostToolPath(ctx, "avbtool"))
248	algorithm := proptools.StringDefault(b.properties.Avb_algorithm, "SHA256_RSA4096")
249	addStr("avb_algorithm", algorithm)
250	key := android.PathForModuleSrc(ctx, proptools.String(b.properties.Avb_private_key))
251	addPath("avb_key_path", key)
252	addStr("avb_add_hash_footer_args", "") // TODO(jiyong): add --rollback_index
253	partitionName := proptools.StringDefault(b.properties.Partition_name, b.Name())
254	addStr("partition_name", partitionName)
255
256	propFile = android.PathForModuleOut(ctx, "prop").OutputPath
257	android.WriteFileRule(ctx, propFile, sb.String())
258	return propFile, deps
259}
260
261var _ android.AndroidMkEntriesProvider = (*bootimg)(nil)
262
263// Implements android.AndroidMkEntriesProvider
264func (b *bootimg) AndroidMkEntries() []android.AndroidMkEntries {
265	return []android.AndroidMkEntries{android.AndroidMkEntries{
266		Class:      "ETC",
267		OutputFile: android.OptionalPathForPath(b.output),
268		ExtraEntries: []android.AndroidMkExtraEntriesFunc{
269			func(ctx android.AndroidMkExtraEntriesContext, entries *android.AndroidMkEntries) {
270				entries.SetString("LOCAL_MODULE_PATH", b.installDir.ToMakePath().String())
271				entries.SetString("LOCAL_INSTALLED_MODULE_STEM", b.installFileName())
272			},
273		},
274	}}
275}
276
277var _ Filesystem = (*bootimg)(nil)
278
279func (b *bootimg) OutputPath() android.Path {
280	return b.output
281}
282
283func (b *bootimg) SignedOutputPath() android.Path {
284	if proptools.Bool(b.properties.Use_avb) {
285		return b.OutputPath()
286	}
287	return nil
288}
289
290var _ android.OutputFileProducer = (*bootimg)(nil)
291
292// Implements android.OutputFileProducer
293func (b *bootimg) OutputFiles(tag string) (android.Paths, error) {
294	if tag == "" {
295		return []android.Path{b.output}, nil
296	}
297	return nil, fmt.Errorf("unsupported module reference tag %q", tag)
298}
299