AbleOS/holey-bytes
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Modified memory interface

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I have no idea what I am doing rn
This commit is contained in:
Erin 2023-08-15 17:05:10 +02:00 committed by ondra05
parent a8f2e4fbdf
commit 9021acf61c
2 changed files with 22 additions and 55 deletions
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54
hbvm/src/lib.rs
View file

@ -24,7 +24,7 @@ mod bmc;
use {
bmc::BlockCopier,
core::{cmp::Ordering, mem::size_of, ops, slice::SliceIndex},
core::{cmp::Ordering, mem::size_of, ops},
derive_more::Display,
hbbytecode::{OpParam, ParamBB, ParamBBB, ParamBBBB, ParamBBD, ParamBBDH, ParamBBW, ParamBD},
value::{Value, ValueVariant},
@ -96,9 +96,9 @@ where
// - Yes, we assume you run 64 bit CPU. Else ?conradluget a better CPU
// sorry 8 bit fans, HBVM won't run on your Speccy :(
unsafe {
match *self
match self
.memory
.load_prog(self.pc)
.prog_read::<u8>(self.pc as _)
.ok_or(VmRunError::ProgramFetchLoadEx(self.pc as _))?
{
UN => {
@ -368,13 +368,7 @@ where
#[inline(always)]
unsafe fn decode<T: OpParam>(&mut self) -> T {
let pc1 = self.pc + 1;
let data = self
.memory
.load_prog_unchecked(pc1..pc1 + size_of::<T>())
.as_ptr()
.cast::<T>()
.read();
let data = self.memory.prog_read_unchecked::<T>(pc1 as _);
self.pc += 1 + size_of::<T>();
data
}
@ -517,39 +511,17 @@ pub trait Memory {
count: usize,
) -> Result<(), StoreError>;
/// Fetch bytes from program section
///
/// # Why?
/// Even Holey Bytes programs operate with
/// single address space, the actual implementation
/// may be different, so for these reasons there is a
/// separate function.
///
/// Also if your memory implementation differentiates between
/// readable and executable memory, this is the way to distinguish
/// the loads.
///
/// # Notice for implementors
/// This is a hot function. This is called on each opcode fetch
/// and instruction decode. Inlining the implementation is highly
/// recommended!
///
/// If you utilise some more heavy memory implementation, consider
/// performing caching as HBVM does not do that for you.
///
/// Has to return all the requested data. If cannot fetch data of requested
/// length, return [`None`].
fn load_prog<I>(&mut self, index: I) -> Option<&I::Output>
where
I: SliceIndex<[u8]>;
/// Fetch bytes from program section, unchecked.
/// Read from program memory to execute
///
/// # Safety
/// You really have to be sure you get the bytes, got me?
unsafe fn load_prog_unchecked<I>(&mut self, index: I) -> &I::Output
where
I: SliceIndex<[u8]>;
/// - Data read have to be valid
unsafe fn prog_read<T>(&mut self, addr: u64) -> Option<T>;
/// Read from program memory to exectue
///
/// # Safety
/// - You have to be really sure that these bytes are there, understand?
unsafe fn prog_read_unchecked<T>(&mut self, addr: u64) -> T;
}
/// Unhandled load access trap

23
hbvm/src/mem/softpaging/mod.rs
View file

@ -1,5 +1,7 @@
//! Platform independent, software paged memory implementation
use core::mem::size_of;
pub mod lookup;
pub mod paging;
@ -63,22 +65,15 @@ impl<'p, PfH: HandlePageFault> Memory for SoftPagedMem<'p, PfH> {
.map_err(StoreError)
}
/// Fetch slice from program memory section
#[inline(always)]
fn load_prog<I>(&mut self, index: I) -> Option<&I::Output>
where
I: SliceIndex<[u8]>,
{
self.program.get(index)
unsafe fn prog_read<T>(&mut self, addr: u64) -> Option<T> {
let addr = addr as usize;
self.program
.get(addr..addr + size_of::<T>())
.map(|x| x.as_ptr().cast::<T>().read())
}
/// Fetch slice from program memory section, unchecked!
#[inline(always)]
unsafe fn load_prog_unchecked<I>(&mut self, index: I) -> &I::Output
where
I: SliceIndex<[u8]>,
{
self.program.get_unchecked(index)
unsafe fn prog_read_unchecked<T>(&mut self, addr: u64) -> T {
self.program.as_ptr().add(addr as _).cast::<T>().read()
}
}