Red Bear OS — microkernel OS in Rust, based on Redox

Derivative of Redox OS (https://www.redox-os.org) adding: - AMD GPU driver (amdgpu) via LinuxKPI compat layer - ext4 filesystem support (ext4d scheme daemon) - ACPI fixes for AMD bare metal (x2APIC, DMAR, IVRS, MCFG) - Custom branding (hostname, os-release, boot identity) Build system is full upstream Redox with RBOS overlay in local/. Patches for kernel, base, and relibc are symlinked from local/patches/ and protected from make clean/distclean. Custom recipes live in local/recipes/ with symlinks into the recipes/ search path. Build: make all CONFIG_NAME=redbear-full Sync: ./local/scripts/sync-upstream.sh
2026-04-12 19:05:00 +01:00
commit 50b731f1b7
3392 changed files with 98327 additions and 0 deletions
@@ -0,0 +1,41 @@
+diff --git a/src/acpi/rsdp.rs b/src/acpi/rsdp.rs
+index f10c5ac9..f3cf3175 100644
+--- a/src/acpi/rsdp.rs
+++ b/src/acpi/rsdp.rs
+@@ -17,9 +17,33 @@ pub struct Rsdp {
+ 
+ impl Rsdp {
+     pub unsafe fn get_rsdp(already_supplied_rsdp: Option<*const u8>) -> Option<Rsdp> {
+-        already_supplied_rsdp.map(|rsdp_ptr| {
+-            // TODO: Validate
+-            unsafe { *(rsdp_ptr as *const Rsdp) }
+        already_supplied_rsdp.and_then(|rsdp_ptr| {
+            let rsdp = unsafe { *(rsdp_ptr as *const Rsdp) };
+
+            // Validate signature "RSD PTR "
+            if &rsdp.signature != b"RSD PTR " {
+                return None;
+            }
+
+            // ACPI 1.0 checksum: sum of first 20 bytes must be zero
+            let bytes_v1 = unsafe { core::slice::from_raw_parts(rsdp_ptr, 20) };
+            if bytes_v1.iter().fold(0u8, |sum, &b| sum.wrapping_add(b)) != 0 {
+                return None;
+            }
+
+            // ACPI 2.0+ extended checksum: sum of entire table (length bytes) must be zero
+            if rsdp.revision >= 2 {
+                let full_len = rsdp._length as usize;
+                if full_len < 36 || full_len > 256 {
+                    return None;
+                }
+                let bytes_full = unsafe { core::slice::from_raw_parts(rsdp_ptr, full_len) };
+                if bytes_full.iter().fold(0u8, |sum, &b| sum.wrapping_add(b)) != 0 {
+                    return None;
+                }
+            }
+
+            Some(rsdp)
+         })
+     }
+