aarch64: Don't advertise FDT to kernel to ensure use of ACPI

The Linux kernel only enabled ACPI if the provided FDT table is a stub [1]. Although this is a violation of the boot Arm Base Boot Requirement 7.4.3 [2] which requires an FDT table (a stub would be sufficient) for simplicity the FDT table is simply skipped which does not cause issues. Fixes: #261 Signed-off-by: Jianyong Wu <[email protected]> [1] https://github.com/torvalds/linux/blob/d528014517f2b0531862c02865b9d4c908019dc4/arch/arm64/kernel/acpi.c#L203 [2] https://developer.arm.com/documentation/den0044/latest
cloud-hypervisor · Jul 21, 2023 · 2e0975f · 2e0975f
1 parent 0be3eff
commit 2e0975f
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/src/efi/mod.rs b/src/efi/mod.rs
@@ -1115,6 +1115,9 @@ pub fn efi_exec(
     let mut ct_index = 0;
 
     // Populate with FDT table if present
+    // To ensure ACPI is used during boot do not include FDT table on aarch64
+    // https://github.com/torvalds/linux/blob/d528014517f2b0531862c02865b9d4c908019dc4/arch/arm64/kernel/acpi.c#L203
+    #[cfg(not(target_arch = "aarch64"))]
     if let Some(fdt_entry) = info.fdt_reservation() {
         ct[ct_index] = efi::ConfigurationTable {
             vendor_guid: Guid::from_fields(