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Diffstat (limited to 'src/peripheral/sau.rs')
| -rw-r--r-- | src/peripheral/sau.rs | 242 |
1 files changed, 0 insertions, 242 deletions
diff --git a/src/peripheral/sau.rs b/src/peripheral/sau.rs deleted file mode 100644 index 6b8477f..0000000 --- a/src/peripheral/sau.rs +++ /dev/null @@ -1,242 +0,0 @@ -//! Security Attribution Unit -//! -//! *NOTE* Available only on Armv8-M and Armv8.1-M, for the following Rust target triples: -//! * `thumbv8m.base-none-eabi` -//! * `thumbv8m.main-none-eabi` -//! * `thumbv8m.main-none-eabihf` -//! -//! For reference please check the section B8.3 of the Armv8-M Architecture Reference Manual. - -use crate::peripheral::SAU; -use bitfield::bitfield; -use volatile_register::{RO, RW}; - -/// Register block -#[repr(C)] -pub struct RegisterBlock { - /// Control Register - pub ctrl: RW<Ctrl>, - /// Type Register - pub _type: RO<Type>, - /// Region Number Register - pub rnr: RW<Rnr>, - /// Region Base Address Register - pub rbar: RW<Rbar>, - /// Region Limit Address Register - pub rlar: RW<Rlar>, - /// Secure Fault Status Register - pub sfsr: RO<Sfsr>, - /// Secure Fault Address Register - pub sfar: RO<Sfar>, -} - -bitfield! { - /// Control Register description - #[repr(C)] - #[derive(Copy, Clone)] - pub struct Ctrl(u32); - get_enable, set_enable: 0; - get_allns, set_allns: 1; -} - -bitfield! { - /// Type Register description - #[repr(C)] - #[derive(Copy, Clone)] - pub struct Type(u32); - u8; - sregion, _: 7, 0; -} - -bitfield! { - /// Region Number Register description - #[repr(C)] - #[derive(Copy, Clone)] - pub struct Rnr(u32); - u8; - get_region, set_region: 7, 0; -} - -bitfield! { - /// Region Base Address Register description - #[repr(C)] - #[derive(Copy, Clone)] - pub struct Rbar(u32); - u32; - get_baddr, set_baddr: 31, 5; -} - -bitfield! { - /// Region Limit Address Register description - #[repr(C)] - #[derive(Copy, Clone)] - pub struct Rlar(u32); - u32; - get_laddr, set_laddr: 31, 5; - get_nsc, set_nsc: 1; - get_enable, set_enable: 0; -} - -bitfield! { - /// Secure Fault Status Register description - #[repr(C)] - #[derive(Copy, Clone)] - pub struct Sfsr(u32); - invep, _: 0; - invis, _: 1; - inver, _: 2; - auviol, _: 3; - invtran, _: 4; - lsperr, _: 5; - sfarvalid, _: 6; - lserr, _: 7; -} - -bitfield! { - /// Secure Fault Address Register description - #[repr(C)] - #[derive(Copy, Clone)] - pub struct Sfar(u32); - u32; - address, _: 31, 0; -} - -/// Possible attribute of a SAU region. -#[derive(Debug)] -pub enum SauRegionAttribute { - /// SAU region is Secure - Secure, - /// SAU region is Non-Secure Callable - NonSecureCallable, - /// SAU region is Non-Secure - NonSecure, -} - -/// Description of a SAU region. -#[derive(Debug)] -pub struct SauRegion { - /// First address of the region, its 5 least significant bits must be set to zero. - pub base_address: u32, - /// Last address of the region, its 5 least significant bits must be set to one. - pub limit_address: u32, - /// Attribute of the region. - pub attribute: SauRegionAttribute, -} - -/// Possible error values returned by the SAU methods. -#[derive(Debug)] -pub enum SauError { - /// The region number parameter to set or get a region must be between 0 and - /// region_numbers() - 1. - RegionNumberTooBig, - /// Bits 0 to 4 of the base address of a SAU region must be set to zero. - WrongBaseAddress, - /// Bits 0 to 4 of the limit address of a SAU region must be set to one. - WrongLimitAddress, -} - -impl SAU { - /// Get the number of implemented SAU regions. - #[inline] - pub fn region_numbers(&self) -> u8 { - self._type.read().sregion() - } - - /// Enable the SAU. - #[inline] - pub fn enable(&mut self) { - unsafe { - self.ctrl.modify(|mut ctrl| { - ctrl.set_enable(true); - ctrl - }); - } - } - - /// Set a SAU region to a region number. - /// SAU regions must be 32 bytes aligned and their sizes must be a multiple of 32 bytes. It - /// means that the 5 least significant bits of the base address of a SAU region must be set to - /// zero and the 5 least significant bits of the limit address must be set to one. - /// The region number must be valid. - /// This function is executed under a critical section to prevent having inconsistent results. - #[inline] - pub fn set_region(&mut self, region_number: u8, region: SauRegion) -> Result<(), SauError> { - critical_section::with(|_| { - let base_address = region.base_address; - let limit_address = region.limit_address; - let attribute = region.attribute; - - if region_number >= self.region_numbers() { - Err(SauError::RegionNumberTooBig) - } else if base_address & 0x1F != 0 { - Err(SauError::WrongBaseAddress) - } else if limit_address & 0x1F != 0x1F { - Err(SauError::WrongLimitAddress) - } else { - // All fields of these registers are going to be modified so we don't need to read them - // before. - let mut rnr = Rnr(0); - let mut rbar = Rbar(0); - let mut rlar = Rlar(0); - - rnr.set_region(region_number); - rbar.set_baddr(base_address >> 5); - rlar.set_laddr(limit_address >> 5); - - match attribute { - SauRegionAttribute::Secure => { - rlar.set_nsc(false); - rlar.set_enable(false); - } - SauRegionAttribute::NonSecureCallable => { - rlar.set_nsc(true); - rlar.set_enable(true); - } - SauRegionAttribute::NonSecure => { - rlar.set_nsc(false); - rlar.set_enable(true); - } - } - - unsafe { - self.rnr.write(rnr); - self.rbar.write(rbar); - self.rlar.write(rlar); - } - - Ok(()) - } - }) - } - - /// Get a region from the SAU. - /// The region number must be valid. - /// This function is executed under a critical section to prevent having inconsistent results. - #[inline] - pub fn get_region(&mut self, region_number: u8) -> Result<SauRegion, SauError> { - critical_section::with(|_| { - if region_number >= self.region_numbers() { - Err(SauError::RegionNumberTooBig) - } else { - unsafe { - self.rnr.write(Rnr(region_number.into())); - } - - let rbar = self.rbar.read(); - let rlar = self.rlar.read(); - - let attribute = match (rlar.get_enable(), rlar.get_nsc()) { - (false, _) => SauRegionAttribute::Secure, - (true, false) => SauRegionAttribute::NonSecure, - (true, true) => SauRegionAttribute::NonSecureCallable, - }; - - Ok(SauRegion { - base_address: rbar.get_baddr() << 5, - limit_address: (rlar.get_laddr() << 5) | 0x1F, - attribute, - }) - } - }) - } -} |