Struct faucon_emu::memory::Tlb

pub struct Tlb { /* fields omitted */ }

The Falcon Translation Lookaside Buffer for mapping code pages in memory.

It consists of multiple TlbEntrys, each representing one physical page.

The valid virtual address range is defined as 0..(1 << (UC_CAPS2 >> 16 & 0xF)) * 0x100 and whenever such an address is accessed, the TLB searches for a corresponding entry. If there is more than one match or no match at all, it is considered an error and a trap should be generated by the CPU.

Implementations

impl Tlb

pub fn new() -> Self

Creates a new instance of the TLB for virtual address translation.

pub fn get_physical_entry(&mut self, address: u16) -> &mut TlbEntry

Gets a mutable reference to the TlbEntry that corresponds to the given physical address.

pub fn translate_addr(&self, address: u32) -> Result<u16, LookupError>

Translates a virtual address to a physical address.

pub fn lookup(&self, address: u32) -> Result<(u8, &TlbEntry), LookupError>

Finds a TlbEntry that corresponds to the given virtual address and returns a reference to it.

If a page fault occurs, a LookupError is returned.

In case the page is found, a (page_index, entry) constellation is returned, where page_index denotes the physical page index and entry the TlbEntry that was found.

pub fn lookup_raw(&self, address: u32) -> u32

Finds a TlbEntry that corresponds to the given virtual address and builds a result value in the following format:

• Bits 0:7 - physical page index
• Bits 8:23 - 0
• Bits 24:26 - flags, ORed across all matches
• Bit 30 - Set if multiple pages were hit
• Bit 31 - Set if no pages were hit

The above format is generated by VTLB operations on the hardware and thus, this method is used to emulate its behavior in instructions.

pub fn lookup_mut(
    &mut self,
    address: u32
) -> Result<(u8, &mut TlbEntry), LookupError>

Finds a TlbEntry that corresponds to the given virtual address and returns a mutable reference to it.

If a page fault occurs, a LookupError is returned.

In case the page is found, a (page_index, entry) constellation is returned, where page_index denotes the physical page index and entry the TlbEntry that was found.