Andrew Walbran | ba47d1d | 2022-12-14 15:21:44 +0000 | [diff] [blame] | 1 | // Copyright 2022, 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 | |
| 15 | //! Wrappers around calls to the hypervisor. |
| 16 | |
Pierre-Clément Tosi | a59103d | 2023-02-02 14:46:55 +0000 | [diff] [blame] | 17 | pub mod trng; |
Andrew Walbran | 9afab67 | 2023-04-17 14:26:23 +0000 | [diff] [blame] | 18 | use self::trng::Error; |
Andrew Walbran | f44f160 | 2023-05-30 14:59:19 +0000 | [diff] [blame] | 19 | use smccc::{ |
Andrew Walbran | 9afab67 | 2023-04-17 14:26:23 +0000 | [diff] [blame] | 20 | error::{positive_or_error_64, success_or_error_64}, |
| 21 | hvc64, |
| 22 | }; |
Pierre-Clément Tosi | a59103d | 2023-02-02 14:46:55 +0000 | [diff] [blame] | 23 | |
Pierre-Clément Tosi | a59103d | 2023-02-02 14:46:55 +0000 | [diff] [blame] | 24 | const ARM_SMCCC_TRNG_VERSION: u32 = 0x8400_0050; |
| 25 | #[allow(dead_code)] |
| 26 | const ARM_SMCCC_TRNG_FEATURES: u32 = 0x8400_0051; |
| 27 | #[allow(dead_code)] |
| 28 | const ARM_SMCCC_TRNG_GET_UUID: u32 = 0x8400_0052; |
| 29 | #[allow(dead_code)] |
| 30 | const ARM_SMCCC_TRNG_RND32: u32 = 0x8400_0053; |
| 31 | const ARM_SMCCC_TRNG_RND64: u32 = 0xc400_0053; |
Pierre-Clément Tosi | a59103d | 2023-02-02 14:46:55 +0000 | [diff] [blame] | 32 | |
| 33 | /// Returns the (major, minor) version tuple, as defined by the SMCCC TRNG. |
| 34 | pub fn trng_version() -> trng::Result<(u16, u16)> { |
| 35 | let args = [0u64; 17]; |
| 36 | |
Andrew Walbran | 9afab67 | 2023-04-17 14:26:23 +0000 | [diff] [blame] | 37 | let version = positive_or_error_64::<Error>(hvc64(ARM_SMCCC_TRNG_VERSION, args)[0])?; |
Pierre-Clément Tosi | a59103d | 2023-02-02 14:46:55 +0000 | [diff] [blame] | 38 | Ok(((version >> 16) as u16, version as u16)) |
| 39 | } |
| 40 | |
| 41 | pub type TrngRng64Entropy = (u64, u64, u64); |
| 42 | |
| 43 | pub fn trng_rnd64(nbits: u64) -> trng::Result<TrngRng64Entropy> { |
| 44 | let mut args = [0u64; 17]; |
| 45 | args[0] = nbits; |
| 46 | |
Andrew Walbran | 9afab67 | 2023-04-17 14:26:23 +0000 | [diff] [blame] | 47 | let regs = hvc64(ARM_SMCCC_TRNG_RND64, args); |
| 48 | success_or_error_64::<Error>(regs[0])?; |
Pierre-Clément Tosi | a59103d | 2023-02-02 14:46:55 +0000 | [diff] [blame] | 49 | |
| 50 | Ok((regs[1], regs[2], regs[3])) |
| 51 | } |