Improve usage of repr(packed)

Author: Caduser2020

src/framebuffer.rs

@@ -66,7 +66,7 @@ pub struct FramebufferField {
 
 /// A framebuffer color descriptor in the palette.
 #[derive(Clone, Copy, Debug, PartialEq)]
-#[repr(C, packed)]
+#[repr(C, packed)] // only repr(C) would add unwanted padding at the end
 pub struct FramebufferColor {
     /// The Red component of the color.
     pub red: u8,

src/lib.rs

@@ -115,7 +115,7 @@ pub struct BootInformation {
 }
 
 #[derive(Clone, Copy)]
-#[repr(C, packed)]
+#[repr(C)]
 struct BootInformationInner {
     total_size: u32,
     _reserved: u32,

src/module.rs

@@ -3,7 +3,7 @@ use header::{Tag, TagIter};
 /// This tag indicates to the kernel what boot module was loaded along with
 /// the kernel image, and where it can be found. 
 #[derive(Clone, Copy, Debug)]
-#[repr(C, packed)]
+#[repr(C, packed)] // only repr(C) would add unwanted padding near name_byte.
 pub struct ModuleTag {
     typ: u32,
     size: u32,

src/rsdp.rs

@@ -13,7 +13,7 @@ const RSDPV1_LENGTH: usize = 20;
 
 /// EFI system table in 32 bit mode
 #[derive(Clone, Copy, Debug)]
-#[repr(C, packed)]
+#[repr(C, packed)] // only repr(C) would add unwanted padding before first_section
 pub struct EFISdt32 {
     typ: u32,
     size: u32,
@@ -29,7 +29,7 @@ impl EFISdt32 {
 
 /// EFI system table in 64 bit mode
 #[derive(Clone, Copy, Debug)]
-#[repr(C, packed)]
+#[repr(C)] 
 pub struct EFISdt64 {
     typ: u32,
     size: u32,