From 361f02166cc939879b58328cbf5e75a050c93e1d Mon Sep 17 00:00:00 2001
From: Aqua-sama <aqua@iserlohn-fortress.net>
Date: Sun, 7 Mar 2021 21:44:12 +0200
Subject: Move multiboot header to its own section

---
 linker.ld  | 70 ++++++++++++++++++++++++++++++--------------------------------
 makefile   |  5 ++++-
 src/boot.S |  4 ++--
 src/idt.cc |  2 +-
 4 files changed, 41 insertions(+), 40 deletions(-)

diff --git a/linker.ld b/linker.ld
index eaf118c..cd4139c 100644
--- a/linker.ld
+++ b/linker.ld
@@ -1,47 +1,45 @@
 ENTRY(_start)
 OUTPUT_FORMAT(elf32-i386)
 
-/* Tell where the various sections of the object files will be put in the final
-   kernel image. */
 SECTIONS
 {
-	/* Begin putting sections at 1 MiB, a conventional place for kernels to be
-	   loaded at by the bootloader. */
-	. = 1M;
+    /* Begin putting sections at 1 MiB */
+    . = 1M;
  
-	/* First put the multiboot header, as it is required to be put very early
-	   early in the image or the bootloader won't recognize the file format.
-	   Next we'll put the .text section. */
-	.text :
-	{
-                *(.multiboot)
-		*(.text)
-	}
+    /* First put the multiboot header, as it is required to be put very early
+     * early in the image or the bootloader won't recognize the file format.
+     */
+    .multiboot : {
+        *(.multiboot.header)
+        *(.multiboot.text)
+    }
+
+    .text : {
+        *(.text*)
+    }
  
-	/* Read-only data. */
-	.rodata :
-	{
-		*(.rodata)
-	}
+    /* Read-only data. */
+    .rodata : {
+        *(.rodata*)
+    }
  
-	/* Read-write data (initialized) */
-	.data :
-	{
-            start_ctors = .;
-            KEEP(*(.init_array));
-            KEEP(*(SORT_BY_INIT_PRIORITY(.init_array.*)));
-            end_ctors = .;
-		*(.data)
-	}
+    /* Read-write data (initialized) */
+    .data : {
+        start_ctors = .;
+        KEEP(*(.init_array));   /* global constructors */
+        end_ctors = .;
+
+        begin_constinit = .;
+        *(.constinit)
+        end_constinit = .;
+
+        *(.data)
+    }
  
-	/* Read-write data (uninitialized) and stack */
-	.bss :
-	{
-		*(COMMON)
-		*(.bss)
-                *(.stack)
-	}
+    /* Read-write data (uninitialized) and stack */
+    .bss : {
+        *(.bss)
+        *(.stack)
+    }
  
-	/* The compiler may produce other sections, by default it will put them in
-	   a segment with the same name. Simply add stuff here as needed. */
 }
diff --git a/makefile b/makefile
index 829d566..afbe1d1 100644
--- a/makefile
+++ b/makefile
@@ -2,7 +2,7 @@ include toolchain.makefile
 include .config
 OBJ_DIR != echo $(CONFIG_OBJ_DIR)
 
-.PHONY: default clean test check-grub run
+.PHONY: default clean test todo run
 default: glitch.elf
 
 include libk/makefile
@@ -42,6 +42,9 @@ clean:
 # testing
 test: $(CXX_TEST_OBJ)
 
+todo:
+	@grep TODO -r libk/ src/ drivers/
+
 # disk image
 glitch.iso: glitch.elf grub/grub.cfg
 	@mkdir -p isodir/boot/grub
diff --git a/src/boot.S b/src/boot.S
index fff1644..b17aea3 100644
--- a/src/boot.S
+++ b/src/boot.S
@@ -9,7 +9,7 @@
 .set MULTIBOOT_ARCHITECTURE, 0          # protected mode i386
 .set MULTIBOOT_HEADER_TAG_END, 0
 
-.section .multiboot
+.section .multiboot.header, "a"
 .align 8
 header_start:
     .int MULTIBOOT_HEADER_MAGIC
@@ -40,7 +40,7 @@ stack_top:
     The linker script specifies _start as the entry point to the kernel and the
     bootloader will jump to this position once the kernel has been loaded.
 */
-.section .text
+.section .multiboot.text, "ax"
 .extern kernel_constructors
 .extern kernel_main
 .global _start
diff --git a/src/idt.cc b/src/idt.cc
index 5022f3e..edf7b37 100644
--- a/src/idt.cc
+++ b/src/idt.cc
@@ -6,7 +6,7 @@
 static_assert(sizeof(IDT::Pointer) == 6);
 constexpr uint8_t irq_base = 0x20;
 
-static IDT::Entry table[256];
+__attribute__((section(".constinit"))) static IDT::Entry table[256];
 static InterruptHandler* handlers[256] = {nullptr};
 
 bool IDT::install(uint8_t irq, InterruptHandler* h) {
-- 
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