/src/td-shim/td-shim-interface/src/acpi.rs

Source
// Copyright (c) 2021 Intel Corporation
// Copyright (c) 2022 Alibaba Cloud
//
// SPDX-License-Identifier: BSD-2-Clause-Patent
use core::mem::size_of;
use zerocopy::{AsBytes, FromBytes, FromZeroes};

pub const ACPI_TABLES_MAX_NUM: usize = 20;
pub const ACPI_RSDP_REVISION: u8 = 2;

#[derive(Debug, PartialEq, Eq)]
pub enum Error {
    InvalidParameter,
    TooManyAcpiTables,
}

pub fn calculate_checksum(data: &[u8]) -> u8 {
    (255 - data.iter().fold(0u8, |acc, x| acc.wrapping_add(*x))).wrapping_add(1)
}

#[repr(packed)]
#[derive(Default, AsBytes, FromBytes, FromZeroes)]
pub struct Rsdp {
    pub signature: [u8; 8],
    pub checksum: u8,
    pub oem_id: [u8; 6],
    pub revision: u8,
    pub _rsdt_addr: u32,
    pub length: u32,
    pub xsdt_addr: u64,
    pub extended_checksum: u8,
    pub _reserved: [u8; 3],
}

impl Rsdp {
    pub fn new(xsdt_addr: u64) -> Rsdp {
        let mut rsdp = Rsdp {
            signature: *b"RSD PTR ",
            checksum: 0,
            oem_id: *b"INTEL ",
            revision: ACPI_RSDP_REVISION,
            length: size_of::<Rsdp>() as u32,
            xsdt_addr,
            ..Default::default()
        };
        rsdp.checksum();
        rsdp
    }

    pub fn set_xsdt(&mut self, xsdt: u64) {
        self.xsdt_addr = xsdt;
        self.checksum();
    }

    fn checksum(&mut self) {
        self.checksum = 0;
        self.extended_checksum = 0;
        self.checksum = calculate_checksum(&self.as_bytes()[0..20]);
        self.extended_checksum = calculate_checksum(self.as_bytes());
    }
}

#[repr(C, packed)]
#[derive(Default, AsBytes, FromBytes, FromZeroes)]
pub struct GenericSdtHeader {
    pub signature: [u8; 4],
    pub length: u32,
    pub revision: u8,
    pub checksum: u8,
    pub oem_id: [u8; 6],
    pub oem_table_id: u64,
    pub oem_revision: u32,
    pub creator_id: u32,
    pub creator_revision: u32,
}

impl GenericSdtHeader {
    pub fn new(signature: &[u8; 4], length: u32, revision: u8) -> Self {
        GenericSdtHeader {
            signature: *signature,
            length,
            revision,
            checksum: 0,
            oem_id: *b"INTEL ",
            oem_table_id: u64::from_le_bytes(*b"SHIM    "),
            oem_revision: 1,
            creator_id: u32::from_le_bytes(*b"SHIM"),
            creator_revision: 1,
        }
    }

    pub fn set_checksum(&mut self, checksum: u8) {
        self.checksum = checksum;
    }
}

#[repr(C, packed)]
#[derive(Default, AsBytes, FromBytes, FromZeroes)]
pub struct Xsdt {
    pub header: GenericSdtHeader,
    pub tables: [u64; ACPI_TABLES_MAX_NUM],
}

impl Xsdt {
    pub fn new() -> Self {
        Xsdt {
            header: GenericSdtHeader::new(b"XSDT", size_of::<GenericSdtHeader>() as u32, 1),
            tables: [0; ACPI_TABLES_MAX_NUM],
        }
    }

    pub fn add_table(&mut self, addr: u64) -> Result<(), Error> {
        if self.header.length < size_of::<GenericSdtHeader>() as u32 {
            Err(Error::InvalidParameter)
        } else {
            let table_num =
                (self.header.length as usize - size_of::<GenericSdtHeader>()) / size_of::<u64>();
            if table_num < ACPI_TABLES_MAX_NUM {
                self.tables[table_num] = addr;
                self.header.length += size_of::<u64>() as u32;
                Ok(())
            } else {
                Err(Error::TooManyAcpiTables)
            }
        }
    }

    pub fn checksum(&mut self) {
        self.header.set_checksum(0);
        self.header.set_checksum(calculate_checksum(
            &self.as_bytes()[..self.header.length as usize],
        ));
    }
}

#[repr(C, packed)]
#[derive(Default, AsBytes, FromBytes, FromZeroes)]
pub struct Ccel {
    pub header: GenericSdtHeader,
    pub cc_type: u8,
    pub cc_subtype: u8,
    pub reserved: u16,
    pub laml: u64,
    pub lasa: u64,
}

impl Ccel {
    pub fn new(cc_type: u8, cc_subtype: u8, laml: u64, lasa: u64) -> Ccel {
        let mut ccel = Ccel {
            header: GenericSdtHeader::new(b"CCEL", size_of::<Ccel>() as u32, 1),
            cc_type,
            cc_subtype,
            reserved: 0,
            laml,
            lasa,
        };
        ccel.checksum();
        ccel
    }

    pub fn checksum(&mut self) {
        self.header.checksum = 0;
        self.header
            .set_checksum(calculate_checksum(self.as_bytes()));
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_calculate_checksum() {
        let mut buf = [0xac; 8];
        buf[7] = 0;
        buf[7] = calculate_checksum(&buf);
        let sum = buf.iter().fold(0u8, |s, v| s.wrapping_add(*v));
        assert_eq!(sum, 0);

        buf[3] = 0xcd;
        buf[6] = 0x1c;
        buf[4] = 0;
        buf[4] = calculate_checksum(&buf);
        let sum = buf.iter().fold(0u8, |s, v| s.wrapping_add(*v));
        assert_eq!(sum, 0);
    }

    #[test]
    fn test_rsdp() {
        let mut rsdp = Rsdp::new(0xabcd1234);
        let sum = rsdp.as_bytes()[0..20]
            .iter()
            .fold(0u8, |s, v| s.wrapping_add(*v));
        assert_eq!(sum, 0);
        let sum = rsdp.as_bytes().iter().fold(0u8, |s, v| s.wrapping_add(*v));
        assert_eq!(sum, 0);

        rsdp.set_xsdt(0xdeadbeaf);
        let sum = rsdp.as_bytes()[0..20]
            .iter()
            .fold(0u8, |s, v| s.wrapping_add(*v));
        assert_eq!(sum, 0);
        let sum = rsdp.as_bytes().iter().fold(0u8, |s, v| s.wrapping_add(*v));
        assert_eq!(sum, 0);
    }

    #[test]
    fn test_xsdt() {
        const CHECK_SUM: u8 = 186;
        let mut xsdt = Xsdt::new();
        assert_eq!(xsdt.header.length as usize, size_of::<GenericSdtHeader>());
        for idx in 0..ACPI_TABLES_MAX_NUM {
            assert!(!xsdt.add_table(idx as u64).is_err());
            assert_eq!(
                xsdt.header.length as usize,
                size_of::<GenericSdtHeader>() + (idx + 1) * 8
            );
        }

        assert!(xsdt
            .add_table(100)
            .is_err_and(|e| e == Error::TooManyAcpiTables));
        assert_eq!(
            xsdt.header.length as usize,
            size_of::<GenericSdtHeader>() + ACPI_TABLES_MAX_NUM * 8
        );
        assert!(xsdt
            .add_table(101)
            .is_err_and(|e| e == Error::TooManyAcpiTables));
        assert_eq!(
            xsdt.header.length as usize,
            size_of::<GenericSdtHeader>() + ACPI_TABLES_MAX_NUM * 8
        );

        xsdt.checksum();
        assert_eq!(xsdt.header.checksum, CHECK_SUM);
    }

    #[test]
    fn test_ccel() {
        let ccel = Ccel::new(2, 0, 0x100, 0);

        assert_eq!(&ccel.header.signature, b"CCEL");
        assert_eq!(ccel.header.checksum, 45);
    }
}

Coverage Report

Created: 2025-10-28 06:53

Line	Count	Source
1		// Copyright (c) 2021 Intel Corporation
2		// Copyright (c) 2022 Alibaba Cloud
3		//
4		// SPDX-License-Identifier: BSD-2-Clause-Patent
5		use core::mem::size_of;
6		use zerocopy::{AsBytes, FromBytes, FromZeroes};
7
8		pub const ACPI_TABLES_MAX_NUM: usize = 20;
9		pub const ACPI_RSDP_REVISION: u8 = 2;
10
11		#[derive(Debug, PartialEq, Eq)]
12		pub enum Error {
13		InvalidParameter,
14		TooManyAcpiTables,
15		}
16
17		pub fn calculate_checksum(data: &[u8]) -> u8 {
18	0	(255 - data.iter().fold(0u8, \|acc, x\| acc.wrapping_add(*x))).wrapping_add(1) Unexecuted instantiation: td_shim_interface::acpi::calculate_checksum::{closure#0} Unexecuted instantiation: td_shim_interface::acpi::calculate_checksum::{closure#0}
19		}
20
21		#[repr(packed)]
22		#[derive(Default, AsBytes, FromBytes, FromZeroes)]
23		pub struct Rsdp {
24		pub signature: [u8; 8],
25		pub checksum: u8,
26		pub oem_id: [u8; 6],
27		pub revision: u8,
28		pub _rsdt_addr: u32,
29		pub length: u32,
30		pub xsdt_addr: u64,
31		pub extended_checksum: u8,
32		pub _reserved: [u8; 3],
33		}
34
35		impl Rsdp {
36		pub fn new(xsdt_addr: u64) -> Rsdp {
37		let mut rsdp = Rsdp {
38		signature: *b"RSD PTR ",
39		checksum: 0,
40		oem_id: *b"INTEL ",
41		revision: ACPI_RSDP_REVISION,
42		length: size_of::<Rsdp>() as u32,
43		xsdt_addr,
44		..Default::default()
45		};
46		rsdp.checksum();
47		rsdp
48		}
49
50		pub fn set_xsdt(&mut self, xsdt: u64) {
51		self.xsdt_addr = xsdt;
52		self.checksum();
53		}
54
55		fn checksum(&mut self) {
56		self.checksum = 0;
57		self.extended_checksum = 0;
58		self.checksum = calculate_checksum(&self.as_bytes()[0..20]);
59		self.extended_checksum = calculate_checksum(self.as_bytes());
60		}
61		}
62
63		#[repr(C, packed)]
64		#[derive(Default, AsBytes, FromBytes, FromZeroes)]
65		pub struct GenericSdtHeader {
66		pub signature: [u8; 4],
67		pub length: u32,
68		pub revision: u8,
69		pub checksum: u8,
70		pub oem_id: [u8; 6],
71		pub oem_table_id: u64,
72		pub oem_revision: u32,
73		pub creator_id: u32,
74		pub creator_revision: u32,
75		}
76
77		impl GenericSdtHeader {
78		pub fn new(signature: &[u8; 4], length: u32, revision: u8) -> Self {
79		GenericSdtHeader {
80		signature: *signature,
81		length,
82		revision,
83		checksum: 0,
84		oem_id: *b"INTEL ",
85		oem_table_id: u64::from_le_bytes(*b"SHIM "),
86		oem_revision: 1,
87		creator_id: u32::from_le_bytes(*b"SHIM"),
88		creator_revision: 1,
89		}
90		}
91
92		pub fn set_checksum(&mut self, checksum: u8) {
93		self.checksum = checksum;
94		}
95		}
96
97		#[repr(C, packed)]
98		#[derive(Default, AsBytes, FromBytes, FromZeroes)]
99		pub struct Xsdt {
100		pub header: GenericSdtHeader,
101		pub tables: [u64; ACPI_TABLES_MAX_NUM],
102		}
103
104		impl Xsdt {
105		pub fn new() -> Self {
106		Xsdt {
107		header: GenericSdtHeader::new(b"XSDT", size_of::<GenericSdtHeader>() as u32, 1),
108		tables: [0; ACPI_TABLES_MAX_NUM],
109		}
110		}
111
112		pub fn add_table(&mut self, addr: u64) -> Result<(), Error> {
113		if self.header.length < size_of::<GenericSdtHeader>() as u32 {
114		Err(Error::InvalidParameter)
115		} else {
116		let table_num =
117		(self.header.length as usize - size_of::<GenericSdtHeader>()) / size_of::<u64>();
118		if table_num < ACPI_TABLES_MAX_NUM {
119		self.tables[table_num] = addr;
120		self.header.length += size_of::<u64>() as u32;
121		Ok(())
122		} else {
123		Err(Error::TooManyAcpiTables)
124		}
125		}
126		}
127
128		pub fn checksum(&mut self) {
129		self.header.set_checksum(0);
130		self.header.set_checksum(calculate_checksum(
131		&self.as_bytes()[..self.header.length as usize],
132		));
133		}
134		}
135
136		#[repr(C, packed)]
137		#[derive(Default, AsBytes, FromBytes, FromZeroes)]
138		pub struct Ccel {
139		pub header: GenericSdtHeader,
140		pub cc_type: u8,
141		pub cc_subtype: u8,
142		pub reserved: u16,
143		pub laml: u64,
144		pub lasa: u64,
145		}
146
147		impl Ccel {
148		pub fn new(cc_type: u8, cc_subtype: u8, laml: u64, lasa: u64) -> Ccel {
149		let mut ccel = Ccel {
150		header: GenericSdtHeader::new(b"CCEL", size_of::<Ccel>() as u32, 1),
151		cc_type,
152		cc_subtype,
153		reserved: 0,
154		laml,
155		lasa,
156		};
157		ccel.checksum();
158		ccel
159		}
160
161		pub fn checksum(&mut self) {
162		self.header.checksum = 0;
163		self.header
164		.set_checksum(calculate_checksum(self.as_bytes()));
165		}
166		}
167
168		#[cfg(test)]
169		mod tests {
170		use super::*;
171
172		#[test]
173		fn test_calculate_checksum() {
174		let mut buf = [0xac; 8];
175		buf[7] = 0;
176		buf[7] = calculate_checksum(&buf);
177		let sum = buf.iter().fold(0u8, \|s, v\| s.wrapping_add(*v));
178		assert_eq!(sum, 0);
179
180		buf[3] = 0xcd;
181		buf[6] = 0x1c;
182		buf[4] = 0;
183		buf[4] = calculate_checksum(&buf);
184		let sum = buf.iter().fold(0u8, \|s, v\| s.wrapping_add(*v));
185		assert_eq!(sum, 0);
186		}
187
188		#[test]
189		fn test_rsdp() {
190		let mut rsdp = Rsdp::new(0xabcd1234);
191		let sum = rsdp.as_bytes()[0..20]
192		.iter()
193		.fold(0u8, \|s, v\| s.wrapping_add(*v));
194		assert_eq!(sum, 0);
195		let sum = rsdp.as_bytes().iter().fold(0u8, \|s, v\| s.wrapping_add(*v));
196		assert_eq!(sum, 0);
197
198		rsdp.set_xsdt(0xdeadbeaf);
199		let sum = rsdp.as_bytes()[0..20]
200		.iter()
201		.fold(0u8, \|s, v\| s.wrapping_add(*v));
202		assert_eq!(sum, 0);
203		let sum = rsdp.as_bytes().iter().fold(0u8, \|s, v\| s.wrapping_add(*v));
204		assert_eq!(sum, 0);
205		}
206
207		#[test]
208		fn test_xsdt() {
209		const CHECK_SUM: u8 = 186;
210		let mut xsdt = Xsdt::new();
211		assert_eq!(xsdt.header.length as usize, size_of::<GenericSdtHeader>());
212		for idx in 0..ACPI_TABLES_MAX_NUM {
213		assert!(!xsdt.add_table(idx as u64).is_err());
214		assert_eq!(
215		xsdt.header.length as usize,
216		size_of::<GenericSdtHeader>() + (idx + 1) * 8
217		);
218		}
219
220		assert!(xsdt
221		.add_table(100)
222		.is_err_and(\|e\| e == Error::TooManyAcpiTables));
223		assert_eq!(
224		xsdt.header.length as usize,
225		size_of::<GenericSdtHeader>() + ACPI_TABLES_MAX_NUM * 8
226		);
227		assert!(xsdt
228		.add_table(101)
229		.is_err_and(\|e\| e == Error::TooManyAcpiTables));
230		assert_eq!(
231		xsdt.header.length as usize,
232		size_of::<GenericSdtHeader>() + ACPI_TABLES_MAX_NUM * 8
233		);
234
235		xsdt.checksum();
236		assert_eq!(xsdt.header.checksum, CHECK_SUM);
237		}
238
239		#[test]
240		fn test_ccel() {
241		let ccel = Ccel::new(2, 0, 0x100, 0);
242
243		assert_eq!(&ccel.header.signature, b"CCEL");
244		assert_eq!(ccel.header.checksum, 45);
245		}
246		}