Replace rand_chacha with rand_hc

The former seems to use some SSE features, which cause LLVM errors since we're compiling for a target that has SSE disabled.

Author: phil-opp

Cargo.lock

@@ -17,7 +17,7 @@ x86_64 = { version = "0.14.8" }
 xmas-elf = "0.8.0"
 raw-cpuid = "10.2.0"
 rand = { version = "0.8.4", default-features = false }
-rand_chacha = { version = "0.3.1", default-features = false }
+rand_hc = "0.3.1"
 
 [dependencies.noto-sans-mono-bitmap]
 version = "0.1.2"

common/Cargo.toml

@@ -1,9 +1,10 @@
-use rand_chacha::{rand_core::SeedableRng, ChaCha20Rng};
+use rand::SeedableRng;
+use rand_hc::Hc128Rng;
 use raw_cpuid::CpuId;
 use x86_64::instructions::{port::Port, random::RdRand};
 
 /// Gather entropy from various sources to seed a RNG.
-pub fn build_rng() -> ChaCha20Rng {
+pub fn build_rng() -> Hc128Rng {
     const ENTROPY_SOURCES: [fn() -> [u8; 32]; 3] = [rd_rand_entropy, tsc_entropy, pit_entropy];
 
     // Collect entropy from different sources and xor them all together.
@@ -17,7 +18,7 @@ pub fn build_rng() -> ChaCha20Rng {
     }
 
     // Construct the RNG.
-    ChaCha20Rng::from_seed(seed)
+    Hc128Rng::from_seed(seed)
 }
 
 /// Gather entropy by requesting random numbers with `RDRAND` instruction if it's available.

common/src/entropy.rs

@@ -5,7 +5,7 @@ use rand::{
     distributions::{Distribution, Uniform},
     seq::IteratorRandom,
 };
-use rand_chacha::ChaCha20Rng;
+use rand_hc::Hc128Rng;
 use usize_conversions::IntoUsize;
 use x86_64::{
     structures::paging::{Page, PageTableIndex, Size4KiB},
@@ -21,7 +21,7 @@ pub struct UsedLevel4Entries {
     entry_state: [bool; 512],
     /// A random number generator that should be used to generate random addresses or
     /// `None` if aslr is disabled.
-    rng: Option<ChaCha20Rng>,
+    rng: Option<Hc128Rng>,
 }
 
 impl UsedLevel4Entries {