# Changelog

## 0.8.0

### Breaking changes

- Updated to `zerocopy` 0.8.2.

### New features

- Added `mair` module with types to build MAIR values.
- Implemented `Default` for `Attributes`, `Descriptor`, `PageTable`, `PhysicalAddress` and
  `VirtualAddress`. Added associated `EMPTY` constant for `Descriptor` and `PageTable`.

## 0.7.1

### New features

- Added `Mapping::translation` method.
- Added `Mapping::size`, `IdMap::size` and `LinearMap::size` methods.
- Derived zerocopy traits for `VirtualAddress`, `PhysicalAddress`, `PageTable` and `Descriptor`.
  This is guarded behind the `zerocopy` feature so the dependency can be avoided if not desired.
- Added `TargetAllocator` for pregenerating a static pagetable for a target device.

## 0.7.0

### Breaking changes

- `Translation::allocate_table` and `Translation::deallocate_table` now takes `&mut self` rather
  than `&self.

### Other changes

- The `Translation` type parameter to `Mapping` no longer needs to be `Clone`.
- `IdMap`, `LinearMap`, `Mapping` and `RootTable` are now `Sync`.

## 0.6.0

### Breaking changes

- Added support for EL2 and EL3 page tables. This requires a new parameter to `IdMap::new`,
  `LinearMap::new`, `Mapping::new` and `RootTable::new`.
- `Attributes::EXECUTE_NEVER` renamed to `Attributes::UXN`.
- `Attributes::DEVICE_NGNRE` and `NORMAL` have been removed in favour of `ATTRIBUTE_INDEX_*`,
  `OUTER_SHAREABLE` and `INNER_SHAREABLE`, to avoid making assumptions about how the MAIR registers
  are programmed.

### New features

- Added `root_address`, `mark_active` and `mark_inactive` methods to `IdMap`, `LinearMap` and
  `Mapping`. These may be used to activate and deactivate the page table manually rather than
  calling `activate` and `deactivate`.
- Added `NS` and `PXN` bits to `Attributes`.

### Bug fixes

- When an invalid descriptor is split into a table, the table descriptors aren't set unless to
  non-zero values unless the original descriptor was.

### Other changes

- `Attributes::ACCESSED` is no longer automatically set on all new mappings. To maintain existing
  behaviour you should explicitly set `Attributes::ACCESSED` whenever calling `map_range` for a
  valid mapping.

## 0.5.0

### Bug fixes

- Reject the `PAGE_OR_TABLE` flag when passed to `map_range`, which would result in corrupt table
  mappings to be created.

### Breaking changes

- Updated `modify_range` to split block entries before traversing them, and pass only the
  descriptors and subregions that are completely covered by the given region to the updater callback
  function.
- Updated `modify_range` to only pass block or page descriptors to the callback function and prevent
  them from being converted into table descriptors inadvertently.
- Added rigid break-before-make (BBM) checks to `map_range` and `modify_range`.
- Marked `activate` and `deactivate` methods as unsafe.

### New features

- Added new `map_range()` alternative `map_range_with_constraints()` with extra `contraints`
  argument.
- Added `walk_range` method that iterates over all block or page descriptorsthat intersect with a
  given region, without permitting the callback to make changes to the descriptors

## 0.4.1

### Bug fixes

- `RootTable`, `Mapping`, `IdMap` and `LinearMap` are now correctly marked as `Send`, as it doesn't
  matter where they are used from.

## 0.4.0

### Breaking changes

- Updated `bitflags` to 2.0.2, which changes the API of `Attributes` a bit.
- Updated `map_range` method to support mapping leaf page table entries without the `VALID` flag.
  `Attributes::VALID` is no longer implicitly set when mapping leaf page table entries.

### New features

- Added `modify_range` method to `IdMap`, `LinearMap` and `Mapping` to update details of a mapped
  range. This can be used e.g. to change flags for some range which is already mapped. As part of
  this, the `Descriptor` struct was added to the public API.
- Added `DBM` and software flags to `Attributes`.

## 0.3.0

### Breaking changes

- Made `Translation` trait responsible for allocating page tables. This should help make it possible
  to use more complex mapping schemes, and to construct page tables in a different context to where
  they are used.
- Renamed `AddressRangeError` to `MapError`, which is now an enum with three variants and implements
  `Display`.
- `From<*const T>` and `From<*mut T>` are no longer implemented for `VirtualAddress`.
- Added support for using TTBR1 as well as TTBR0; this changes various constructors to take an extra
  parameter.

### New features

- Made `alloc` dependency optional via a feature flag.
- Added support for linear mappings with new `LinearMap`.
- Implemented subtraction of usize from address types.

### Bugfixes

- Fixed memory leak introduced in 0.2.0: dropping a page table will now actually free its memory.

## 0.2.1

### New features

- Implemented `Debug` and `Display` for `MemoryRegion`.
- Implemented `From<Range<VirtualAddress>>` for `MemoryRegion`.
- Implemented arithmetic operations for `PhysicalAddress` and `VirtualAddress`.

## 0.2.0

### Breaking changes

- Added bounds check to `IdMap::map_range`; it will now return an error if you attempt to map a
  virtual address outside the range of the page table given its configured root level.

### New features

- Implemented `Debug` for `PhysicalAddress` and `VirtualAddress`.
- Validate that chosen root level is supported.

### Bugfixes

- Fixed bug in `Display` and `Drop` implementation for `RootTable` that would result in a crash for
  any pagetable with non-zero mappings.
- Fixed `Display` implementation for `PhysicalAddress` and `VirtualAddress` to use correct number of
  digits.

## 0.1.0

Initial release.