1 // Copyright 2018 The ChromiumOS Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #[cfg(any(target_os = "android", target_os = "linux"))]
6 use std::collections::BTreeMap;
7 use std::fs::File;
8 use std::fs::OpenOptions;
9 use std::io::Write;
10 use std::path::PathBuf;
11
12 use arch::android::create_android_fdt;
13 use arch::apply_device_tree_overlays;
14 use arch::DtbOverlay;
15 use base::open_file_or_duplicate;
16 use cros_fdt::Error;
17 use cros_fdt::Fdt;
18 use resources::AddressRange;
19 use vm_memory::GuestAddress;
20
create_config_node(fdt: &mut Fdt, kernel_region: AddressRange) -> cros_fdt::Result<()>21 fn create_config_node(fdt: &mut Fdt, kernel_region: AddressRange) -> cros_fdt::Result<()> {
22 let addr: u32 = kernel_region
23 .start
24 .try_into()
25 .map_err(|_| Error::PropertyValueTooLarge)?;
26 let size: u32 = kernel_region
27 .len()
28 .expect("invalid kernel_region")
29 .try_into()
30 .map_err(|_| Error::PropertyValueTooLarge)?;
31
32 let config_node = fdt.root_mut().subnode_mut("config")?;
33 config_node.set_prop("kernel-address", addr)?;
34 config_node.set_prop("kernel-size", size)?;
35 Ok(())
36 }
37
create_chosen_node( fdt: &mut Fdt, initrd: Option<(GuestAddress, usize)>, ) -> cros_fdt::Result<()>38 fn create_chosen_node(
39 fdt: &mut Fdt,
40 initrd: Option<(GuestAddress, usize)>,
41 ) -> cros_fdt::Result<()> {
42 let chosen_node = fdt.root_mut().subnode_mut("chosen")?;
43
44 if let Some((initrd_addr, initrd_size)) = initrd {
45 let initrd_start = initrd_addr.offset() as u32;
46 let initrd_end = initrd_start + initrd_size as u32;
47 chosen_node.set_prop("linux,initrd-start", initrd_start)?;
48 chosen_node.set_prop("linux,initrd-end", initrd_end)?;
49 }
50
51 Ok(())
52 }
53
54 /// Creates a flattened device tree containing all of the parameters for the
55 /// kernel and returns it as DTB.
56 ///
57 /// # Arguments
58 ///
59 /// * `android_fstab` - the File object for the android fstab
create_fdt( android_fstab: Option<File>, dump_device_tree_blob: Option<PathBuf>, device_tree_overlays: Vec<DtbOverlay>, kernel_region: AddressRange, initrd: Option<(GuestAddress, usize)>, ) -> Result<Vec<u8>, Error>60 pub fn create_fdt(
61 android_fstab: Option<File>,
62 dump_device_tree_blob: Option<PathBuf>,
63 device_tree_overlays: Vec<DtbOverlay>,
64 kernel_region: AddressRange,
65 initrd: Option<(GuestAddress, usize)>,
66 ) -> Result<Vec<u8>, Error> {
67 let mut fdt = Fdt::new(&[]);
68 // The whole thing is put into one giant node with some top level properties
69 if let Some(android_fstab) = android_fstab {
70 create_android_fdt(&mut fdt, android_fstab)?;
71 }
72
73 create_config_node(&mut fdt, kernel_region)?;
74 create_chosen_node(&mut fdt, initrd)?;
75
76 // Done writing base FDT, now apply DT overlays
77 apply_device_tree_overlays(
78 &mut fdt,
79 device_tree_overlays,
80 #[cfg(any(target_os = "android", target_os = "linux"))]
81 vec![],
82 #[cfg(any(target_os = "android", target_os = "linux"))]
83 &BTreeMap::new(),
84 )?;
85
86 let fdt_final = fdt.finish()?;
87
88 if let Some(file_path) = dump_device_tree_blob {
89 let mut fd = open_file_or_duplicate(
90 &file_path,
91 OpenOptions::new()
92 .read(true)
93 .create(true)
94 .truncate(true)
95 .write(true),
96 )
97 .map_err(|e| Error::FdtIoError(e.into()))?;
98 fd.write_all(&fdt_final)
99 .map_err(|e| Error::FdtDumpIoError(e, file_path.clone()))?;
100 }
101
102 Ok(fdt_final)
103 }
104