From 3bf381caf86417264ae5e985dc28668a1fac1875 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Fri, 3 Mar 2023 18:56:23 -0700
Subject: [PATCH] Do not panic if ACPI is not available

---
 src/scheme/acpi.rs | 14 +++++++-------
 src/scheme/irq.rs  | 18 ++++++++++++------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/src/scheme/acpi.rs b/src/scheme/acpi.rs
index fd0929e..f9bc738 100644
--- a/src/scheme/acpi.rs
+++ b/src/scheme/acpi.rs
@@ -87,13 +87,13 @@ impl AcpiScheme {
         DATA.call_once(|| {
             data_init = true;
 
-            let rsdt_or_xsdt = RXSDT_ENUM
-                .get()
-                .expect("expected RXSDT_ENUM to be initialized before AcpiScheme");
-
-            let table = match rsdt_or_xsdt {
-                RxsdtEnum::Rsdt(rsdt) => rsdt.as_slice(),
-                RxsdtEnum::Xsdt(xsdt) => xsdt.as_slice(),
+            let table = match RXSDT_ENUM.get() {
+                Some(RxsdtEnum::Rsdt(rsdt)) => rsdt.as_slice(),
+                Some(RxsdtEnum::Xsdt(xsdt)) => xsdt.as_slice(),
+                None => {
+                    log::warn!("expected RXSDT_ENUM to be initialized before AcpiScheme, is ACPI available?");
+                    &[]
+                }
             };
 
             Box::from(table)
diff --git a/src/scheme/irq.rs b/src/scheme/irq.rs
index abd7b59..c6cb16a 100644
--- a/src/scheme/irq.rs
+++ b/src/scheme/irq.rs
@@ -87,12 +87,18 @@ impl IrqScheme {
         let cpus = {
             use crate::acpi::madt::*;
 
-            let madt: &Madt = unsafe { MADT.as_ref().unwrap() };
-
-            madt.iter().filter_map(|entry| match entry {
-                MadtEntry::LocalApic(apic) => Some(apic.id),
-                _ => None,
-            }).collect::<Vec<_>>()
+            match unsafe { MADT.as_ref() } {
+                Some(madt) => {
+                    madt.iter().filter_map(|entry| match entry {
+                        MadtEntry::LocalApic(apic) => Some(apic.id),
+                        _ => None,
+                    }).collect::<Vec<_>>()
+                },
+                None => {
+                    log::warn!("no MADT found, defaulting to 1 CPU");
+                    vec!(0)
+                }
+            }
         };
         #[cfg(not(all(feature = "acpi", any(target_arch = "x86", target_arch = "x86_64"))))]
         let cpus = vec!(0);