Use the correct entry flags for kernel sections

src/memory/paging/entry.rs

@@ -1,4 +1,5 @@
 use memory::Frame;
+use multiboot2::ElfSection;
 
 pub struct Entry(u64);
 
@@ -45,3 +46,26 @@ bitflags! {
         const NO_EXECUTE =      1 << 63,
     }
 }
+
+
+impl EntryFlags {
+    pub fn from_elf_section_flags(section: &ElfSection) -> EntryFlags {
+        use multiboot2::{ELF_SECTION_ALLOCATED, ELF_SECTION_WRITABLE,
+            ELF_SECTION_EXECUTABLE};
+
+        let mut flags = EntryFlags::empty();
+
+        if section.flags().contains(ELF_SECTION_ALLOCATED) {
+            // section is loaded to memory
+            flags = flags | PRESENT;
+        }
+        if section.flags().contains(ELF_SECTION_WRITABLE) {
+            flags = flags | WRITABLE;
+        }
+        if !section.flags().contains(ELF_SECTION_EXECUTABLE) {
+            flags = flags | NO_EXECUTE;
+        }
+
+        flags
+    }
+}

src/memory/paging/mod.rs

@@ -173,7 +173,7 @@ pub fn remap_the_kernel<A>(allocator: &mut A, boot_info: &BootInformation)
             println!("mapping section at addr: {:#x}, size: {:#x}",
                 section.addr, section.size);
 
-            let flags = WRITABLE; // TODO use real section flags
+            let flags = EntryFlags::from_elf_section_flags(section);
 
             let start_frame = Frame::containing_address(section.start_address());
             let end_frame = Frame::containing_address(section.end_address() - 1);