diff options
Diffstat (limited to 'src/shared/descriptor.rs')
| -rw-r--r-- | src/shared/descriptor.rs | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/src/shared/descriptor.rs b/src/shared/descriptor.rs index 201d8cc..32abb79 100644 --- a/src/shared/descriptor.rs +++ b/src/shared/descriptor.rs @@ -1,6 +1,7 @@ //! Fields which are common to all segment-section and gate descriptors use shared::PrivilegeLevel; +use shared::segmentation; /// System-Segment and Gate-Descriptor Types for IA32e mode. When the `S` /// (descriptor type) flag in a segment descriptor is clear, the descriptor type @@ -24,6 +25,7 @@ pub enum SystemType { /// A high-level representation of a descriptor type. One can convert to and /// from the `Flags` bitfield to encode/decode an actual descriptor. +#[repr(u8)] pub enum Type { SystemDescriptor { /// false/0: 16-bit @@ -31,6 +33,10 @@ pub enum Type { size: bool, ty: SystemType }, + SegmentDescriptor { + ty: segmentation::Type, + accessed: bool + } } impl Type { @@ -38,6 +44,8 @@ impl Type { match self { Type::SystemDescriptor { size, ty } => (size as u8) << 3 | (ty as u8) | FLAGS_TYPE_SYS.bits, + Type::SegmentDescriptor { ty, accessed } => + (accessed as u8) | ty.pack() | FLAGS_TYPE_SYS.bits, } } } @@ -59,6 +67,7 @@ bitflags!{ // Is system descriptor const FLAGS_TYPE_SYS = 0 << 4, + const FLAGS_TYPE_SEG = 1 << 4, // System-Segment and Gate-Descriptor Types. // When the S (descriptor type) flag in a segment descriptor is clear, @@ -81,6 +90,82 @@ bitflags!{ const FLAGS_TYPE_SYS_NATIVE_CALL_GATE = 0b0_1100, const FLAGS_TYPE_SYS_NATIVE_INTERRUPT_GATE = 0b0_1110, const FLAGS_TYPE_SYS_NATIVE_TRAP_GATE = 0b0_1111, + + // Code- and Data-Segment Descriptor Types. + // When the S (descriptor type) flag in a segment descriptor is set, + // the descriptor is for either a code or a data segment. + + /// Data or code, accessed + const FLAGS_TYPE_SEG_ACCESSED = 0b1_0001, + + const FLAGS_TYPE_DATA = 0b1_0000, + const FLAGS_TYPE_CODE = 0b1_1000, + + // Data => permissions + const FLAGS_TYPE_SEG_D_WRITE = 0b1_0010, + const FLAGS_TYPE_SEG_D_EXPAND_DOWN = 0b1_0100, + + // Code => permissions + const FLAGS_TYPE_SEG_C_READ = 0b1_0010, + const FLAGS_TYPE_SEG_D_CONFORMING = 0b1_0100, + + /// Data Read-Only + const FLAGS_TYPE_SEG_D_RO = FLAGS_TYPE_DATA.bits, + /// Data Read-Only, accessed + const FLAGS_TYPE_SEG_D_ROA = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_ACCESSED.bits, + /// Data Read/Write + const FLAGS_TYPE_SEG_D_RW = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_D_WRITE.bits, + /// Data Read/Write, accessed + const FLAGS_TYPE_SEG_D_RWA = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_D_WRITE.bits + | FLAGS_TYPE_SEG_ACCESSED.bits, + /// Data Read-Only, expand-down + const FLAGS_TYPE_SEG_D_ROEXD = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_D_EXPAND_DOWN.bits, + /// Data Read-Only, expand-down, accessed + const FLAGS_TYPE_SEG_D_ROEXDA = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_D_EXPAND_DOWN.bits + | FLAGS_TYPE_SEG_ACCESSED.bits, + /// Data Read/Write, expand-down + const FLAGS_TYPE_SEG_D_RWEXD = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_D_WRITE.bits + | FLAGS_TYPE_SEG_D_EXPAND_DOWN.bits, + /// Data Read/Write, expand-down, accessed + const FLAGS_TYPE_SEG_D_RWEXDA = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_D_WRITE.bits + | FLAGS_TYPE_SEG_D_EXPAND_DOWN.bits + | FLAGS_TYPE_SEG_ACCESSED.bits, + + /// Code Execute-Only + const FLAGS_TYPE_SEG_C_EO = FLAGS_TYPE_DATA.bits, + /// Code Execute-Only, accessed + const FLAGS_TYPE_SEG_C_EOA = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_ACCESSED.bits, + /// Code Execute/Read + const FLAGS_TYPE_SEG_C_ER = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_C_READ.bits, + /// Code Execute/Read, accessed + const FLAGS_TYPE_SEG_C_ERA = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_C_READ.bits + | FLAGS_TYPE_SEG_ACCESSED.bits, + /// Code Execute-Only, conforming + const FLAGS_TYPE_SEG_C_EOC = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_D_CONFORMING.bits, + /// Code Execute-Only, conforming, accessed + const FLAGS_TYPE_SEG_C_EOCA = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_D_CONFORMING.bits + | FLAGS_TYPE_SEG_ACCESSED.bits, + /// Code Execute/Read, conforming + const FLAGS_TYPE_SEG_C_ERC = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_C_READ.bits + | FLAGS_TYPE_SEG_D_CONFORMING.bits, + /// Code Execute/Read, conforming, accessed + const FLAGS_TYPE_SEG_C_ERCA = FLAGS_TYPE_DATA.bits + | FLAGS_TYPE_SEG_C_READ.bits + | FLAGS_TYPE_SEG_D_CONFORMING.bits + | FLAGS_TYPE_SEG_ACCESSED.bits, } } |