diff --git a/rmm b/rmm
index ea4cfb2cbf..5f9a587968 160000
--- a/rmm
+++ b/rmm
@@ -1 +1 @@
-Subproject commit ea4cfb2cbffafe5b268607a00ad3d51a6fc0617d
+Subproject commit 5f9a587968fc914c0dacd45c4a89a8a72c074cde
diff --git a/src/acpi/hpet.rs b/src/acpi/hpet.rs
index 9931f3e29c..dce60a732e 100644
--- a/src/acpi/hpet.rs
+++ b/src/acpi/hpet.rs
@@ -9,7 +9,7 @@ use crate::{
 
 use super::{find_sdt, sdt::Sdt, ACPI_TABLE};
 
-#[repr(packed)]
+#[repr(C, packed)]
 #[derive(Clone, Copy, Debug, Default)]
 pub struct GenericAddressStructure {
     _address_space: u8,
@@ -19,7 +19,7 @@ pub struct GenericAddressStructure {
     pub address: u64,
 }
 
-#[repr(packed)]
+#[repr(C, packed)]
 #[derive(Clone, Copy, Debug)]
 pub struct Hpet {
     pub header: Sdt,
diff --git a/src/acpi/madt.rs b/src/acpi/madt.rs
index ab55f0ec46..785d82dc9d 100644
--- a/src/acpi/madt.rs
+++ b/src/acpi/madt.rs
@@ -221,7 +221,7 @@ impl Madt {
 
 /// MADT Local APIC
 #[derive(Clone, Copy, Debug)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct MadtLocalApic {
     /// Processor ID
     pub processor: u8,
@@ -233,7 +233,7 @@ pub struct MadtLocalApic {
 
 /// MADT I/O APIC
 #[derive(Clone, Copy, Debug)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct MadtIoApic {
     /// I/O APIC ID
     pub id: u8,
@@ -247,7 +247,7 @@ pub struct MadtIoApic {
 
 /// MADT Interrupt Source Override
 #[derive(Clone, Copy, Debug)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct MadtIntSrcOverride {
     /// Bus Source
     pub bus_source: u8,
diff --git a/src/acpi/sdt.rs b/src/acpi/sdt.rs
index d5d23aced1..6c7bd6cdc4 100644
--- a/src/acpi/sdt.rs
+++ b/src/acpi/sdt.rs
@@ -1,7 +1,7 @@
 use core::mem;
 
 #[derive(Copy, Clone, Debug)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct Sdt {
     pub signature: [u8; 4],
     pub length: u32,
diff --git a/src/arch/aarch64/interrupt/handler.rs b/src/arch/aarch64/interrupt/handler.rs
index 97233e07ea..7083329589 100644
--- a/src/arch/aarch64/interrupt/handler.rs
+++ b/src/arch/aarch64/interrupt/handler.rs
@@ -1,7 +1,7 @@
 use crate::syscall::IntRegisters;
 
 #[derive(Default)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct ScratchRegisters {
     pub x0: usize,
     pub x1: usize,
@@ -56,7 +56,7 @@ impl ScratchRegisters {
 }
 
 #[derive(Default)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct PreservedRegisters {
     //TODO: is X30 a preserved register?
     pub x19: usize,
@@ -91,7 +91,7 @@ impl PreservedRegisters {
 }
 
 #[derive(Default)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct IretRegisters {
     // occurred
     // The exception vector disambiguates at which EL the interrupt
@@ -111,7 +111,7 @@ impl IretRegisters {
 }
 
 #[derive(Default)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct InterruptStack {
     pub iret: IretRegisters,
     pub scratch: ScratchRegisters,
diff --git a/src/arch/aarch64/interrupt/syscall.rs b/src/arch/aarch64/interrupt/syscall.rs
index d59e4d58c9..40bb7e1624 100644
--- a/src/arch/aarch64/interrupt/syscall.rs
+++ b/src/arch/aarch64/interrupt/syscall.rs
@@ -5,7 +5,7 @@ pub unsafe extern "C" fn do_exception_unhandled() {}
 pub unsafe extern "C" fn do_exception_synchronous() {}
 
 #[allow(dead_code)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct SyscallStack {
     pub elr_el1: usize,
     pub padding: usize,
diff --git a/src/arch/aarch64/rmm.rs b/src/arch/aarch64/rmm.rs
index 7a741dda05..a8d09d8c3f 100644
--- a/src/arch/aarch64/rmm.rs
+++ b/src/arch/aarch64/rmm.rs
@@ -25,7 +25,7 @@ pub enum BootloaderMemoryKind {
 
 // Keep synced with OsMemoryEntry in bootloader
 #[derive(Clone, Copy, Debug)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct BootloaderMemoryEntry {
     pub base: u64,
     pub size: u64,
diff --git a/src/arch/aarch64/start.rs b/src/arch/aarch64/start.rs
index ab619a50cb..f21a684e62 100644
--- a/src/arch/aarch64/start.rs
+++ b/src/arch/aarch64/start.rs
@@ -22,7 +22,7 @@ pub static CPU_COUNT: AtomicU32 = AtomicU32::new(0);
 pub static AP_READY: AtomicBool = AtomicBool::new(false);
 static BSP_READY: AtomicBool = AtomicBool::new(false);
 
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct KernelArgs {
     kernel_base: usize,
     kernel_size: usize,
@@ -191,7 +191,7 @@ pub unsafe extern "C" fn kstart(args_ptr: *const KernelArgs) -> ! {
     crate::kmain(CPU_COUNT.load(Ordering::SeqCst), bootstrap);
 }
 
-#[repr(packed)]
+#[repr(C, packed)]
 #[allow(unused)]
 pub struct KernelArgsAp {
     cpu_id: u64,
diff --git a/src/arch/x86/gdt.rs b/src/arch/x86/gdt.rs
index c8511b6a79..d3be108a77 100644
--- a/src/arch/x86/gdt.rs
+++ b/src/arch/x86/gdt.rs
@@ -129,7 +129,7 @@ pub struct ProcessorControlRegion {
     pub _all_ones: u8,
 }
 
-// NOTE: Despite not using #[repr(packed)], we do know that while there may be some padding
+// NOTE: Despite not using #[repr(C, packed)], we do know that while there may be some padding
 // inserted before and after the TSS, the main TSS structure will remain intact.
 #[repr(C, align(16))]
 pub struct TssWrapper(pub TaskStateSegment);
@@ -233,7 +233,7 @@ pub unsafe fn init_paging(stack_offset: usize, cpu_id: LogicalCpuId) {
 }
 
 #[derive(Copy, Clone, Debug)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct GdtEntry {
     pub limitl: u16,
     pub offsetl: u16,
diff --git a/src/arch/x86/interrupt/handler.rs b/src/arch/x86/interrupt/handler.rs
index ea0f7c0bd5..c8f3e27eed 100644
--- a/src/arch/x86/interrupt/handler.rs
+++ b/src/arch/x86/interrupt/handler.rs
@@ -5,7 +5,7 @@ use crate::{memory::ArchIntCtx, syscall::IntRegisters};
 use super::super::flags::*;
 
 #[derive(Default)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct ScratchRegisters {
     pub edx: usize,
     pub ecx: usize,
@@ -21,7 +21,7 @@ impl ScratchRegisters {
 }
 
 #[derive(Default)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct PreservedRegisters {
     pub ebp: usize,
     pub esi: usize,
@@ -39,7 +39,7 @@ impl PreservedRegisters {
 }
 
 #[derive(Default)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct IretRegisters {
     pub eip: usize,
     pub cs: usize,
@@ -67,7 +67,7 @@ impl IretRegisters {
 }
 
 #[derive(Default)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct InterruptStack {
     pub gs: usize,
     pub preserved: PreservedRegisters,
@@ -177,7 +177,7 @@ impl InterruptStack {
 }
 
 #[derive(Default)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct InterruptErrorStack {
     pub code: usize,
     pub inner: InterruptStack,
diff --git a/src/arch/x86/rmm.rs b/src/arch/x86/rmm.rs
index 79cdec7ba1..b0ad69c8dc 100644
--- a/src/arch/x86/rmm.rs
+++ b/src/arch/x86/rmm.rs
@@ -25,7 +25,7 @@ pub enum BootloaderMemoryKind {
 
 // Keep synced with OsMemoryEntry in bootloader
 #[derive(Clone, Copy, Debug)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct BootloaderMemoryEntry {
     pub base: u64,
     pub size: u64,
diff --git a/src/arch/x86/start.rs b/src/arch/x86/start.rs
index 3a91671180..3654cb3932 100644
--- a/src/arch/x86/start.rs
+++ b/src/arch/x86/start.rs
@@ -31,7 +31,7 @@ pub static CPU_COUNT: AtomicU32 = AtomicU32::new(0);
 pub static AP_READY: AtomicBool = AtomicBool::new(false);
 static BSP_READY: AtomicBool = AtomicBool::new(false);
 
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct KernelArgs {
     kernel_base: u64,
     kernel_size: u64,
@@ -214,7 +214,7 @@ pub unsafe extern "C" fn kstart(args_ptr: *const KernelArgs) -> ! {
     crate::kmain(CPU_COUNT.load(Ordering::SeqCst), bootstrap);
 }
 
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct KernelArgsAp {
     cpu_id: u64,
     page_table: u64,
diff --git a/src/arch/x86_64/gdt.rs b/src/arch/x86_64/gdt.rs
index 0b24d6617e..bb5482f9ba 100644
--- a/src/arch/x86_64/gdt.rs
+++ b/src/arch/x86_64/gdt.rs
@@ -266,7 +266,7 @@ pub unsafe fn init_paging(stack_offset: usize, cpu_id: LogicalCpuId) {
     crate::percpu::init_tlb_shootdown(cpu_id, &mut pcr.percpu);
 }
 #[derive(Copy, Clone, Debug)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct GdtEntry {
     pub limitl: u16,
     pub offsetl: u16,
diff --git a/src/arch/x86_64/rmm.rs b/src/arch/x86_64/rmm.rs
index 503fc273ae..372b49dd78 100644
--- a/src/arch/x86_64/rmm.rs
+++ b/src/arch/x86_64/rmm.rs
@@ -24,7 +24,7 @@ pub enum BootloaderMemoryKind {
 
 // Keep synced with OsMemoryEntry in bootloader
 #[derive(Clone, Copy, Debug)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct BootloaderMemoryEntry {
     pub base: u64,
     pub size: u64,
diff --git a/src/arch/x86_64/start.rs b/src/arch/x86_64/start.rs
index c3ab2218f6..b5f48f8f7b 100644
--- a/src/arch/x86_64/start.rs
+++ b/src/arch/x86_64/start.rs
@@ -33,7 +33,7 @@ pub static CPU_COUNT: AtomicU32 = AtomicU32::new(0);
 pub static AP_READY: AtomicBool = AtomicBool::new(false);
 static BSP_READY: AtomicBool = AtomicBool::new(false);
 
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct KernelArgs {
     kernel_base: u64,
     kernel_size: u64,
@@ -225,7 +225,7 @@ pub unsafe extern "C" fn kstart(args_ptr: *const KernelArgs) -> ! {
     crate::kmain(CPU_COUNT.load(Ordering::SeqCst), bootstrap);
 }
 
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct KernelArgsAp {
     // TODO: u32?
     cpu_id: u64,
diff --git a/src/arch/x86_shared/device/tsc.rs b/src/arch/x86_shared/device/tsc.rs
index 602dd17aaf..d4ae8ec413 100644
--- a/src/arch/x86_shared/device/tsc.rs
+++ b/src/arch/x86_shared/device/tsc.rs
@@ -26,7 +26,7 @@ bitflags! {
 }
 
 // https://www.kernel.org/doc/html/v5.9/virt/kvm/msr.html
-#[repr(packed)]
+#[repr(C, packed)]
 #[derive(Clone, Copy, Debug)]
 struct PvclockVcpuTimeInfo {
     version: u32,
diff --git a/src/arch/x86_shared/idt.rs b/src/arch/x86_shared/idt.rs
index 99a260cbba..54bdb2ccc3 100644
--- a/src/arch/x86_shared/idt.rs
+++ b/src/arch/x86_shared/idt.rs
@@ -308,7 +308,7 @@ bitflags! {
 }
 
 #[derive(Copy, Clone, Debug, Default)]
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct IdtEntry {
     offsetl: u16,
     selector: u16,
diff --git a/syscall b/syscall
index 99f49db824..227f7fd487 160000
--- a/syscall
+++ b/syscall
@@ -1 +1 @@
-Subproject commit 99f49db8245c326295f10676832298d6f1e7ea2a
+Subproject commit 227f7fd4873b17680957c75604cf4a5a674f5792