From 5fc90ea24013dc175ef124843e71db819043ed34 Mon Sep 17 00:00:00 2001
From: starnakin <camille@chauvet.pro>
Date: Tue, 15 Oct 2024 00:29:46 +0200
Subject: [PATCH] fix: paging with higher half kernel

---
 src/boot.s          |  2 ++
 src/kernel.c        |  3 +++
 src/memory/memory.c | 38 +++++++++++++++++++++++++++++++-------
 3 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/src/boot.s b/src/boot.s
index 6295a58..611aa50 100644
--- a/src/boot.s
+++ b/src/boot.s
@@ -21,6 +21,8 @@ stack_top:
 # Preallocate pages used for paging. Don't hard-code addresses and assume they
 # are available, as the bootloader might have loaded its multiboot structures or
 # modules there. This lets the bootloader know it must avoid the addresses.
+.global boot_page_directory
+.global boot_page_table1
 .section .bss, "aw", @nobits
 	.align 4096
 boot_page_directory:
diff --git a/src/kernel.c b/src/kernel.c
index cceb2dd..1bf9676 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -1,3 +1,4 @@
+#include "alloc.h"
 #include "drivers.h"
 #include "gdt.h"
 #include "idt.h"
@@ -33,5 +34,7 @@ void kernel_main(void)
 	        "I see no way to confuse an array of 256 seg:off pairs with a "
 	        "complex 8*unknown quantity -byte descriptor table. -- Troy "
 	        "Martin 03:50, 22 March 2009 (UTC)\n");
+	while (!kmalloc(10))
+		;
 	shell_init();
 }
diff --git a/src/memory/memory.c b/src/memory/memory.c
index 4262a3b..df51a0a 100644
--- a/src/memory/memory.c
+++ b/src/memory/memory.c
@@ -1,19 +1,43 @@
 #include "memory.h"
+#include "kprintf.h"
 #include "string.h"
+
 #include <stdint.h>
 
-extern void load_page_directory(uint32_t *);
 extern void enable_paging(void);
+extern void load_page_directory(uint32_t *);
 
-uint32_t page_directory_entries[1024] __attribute__((aligned(4096)));
+extern uint32_t boot_page_table1;
+extern uint32_t boot_page_directory;
+
+// Pour récupérer une entrée spécifique
+uint32_t *page_directory = &boot_page_directory;
 uint32_t page_table_entries[1024] __attribute__((aligned(4096)));
 
+unsigned long read_cr3()
+{
+	unsigned long cr3_value;
+
+	// Inline assembly to read CR3
+	__asm__ volatile(
+	    "mov %%cr3, %0" // Move the value of CR3 into cr3_value
+	    : "=r"(
+		cr3_value) // Output operand: cr3_value will receive the value
+	    :              // No input operands
+	    :              // No clobber list
+	);
+
+	return cr3_value;
+}
+
+static inline void load_cr3(uint64_t cr3_value)
+{
+	asm volatile("mov %0, %%cr3" ::"r"(cr3_value) : "memory");
+}
+
 void init_memory(void)
 {
-	memset(page_directory_entries, INIT_FLAGS, 1024);
 	for (int i = 0; i < 1024; i++)
 		page_table_entries[i] = (i << 12) | INIT_FLAGS;
-	page_directory_entries[0] = (uint32_t)page_table_entries | INIT_FLAGS;
-	load_page_directory(page_directory_entries);
-	enable_paging();
-}
+	page_directory[1] = (uint32_t)page_table_entries | INIT_FLAGS;
+}
\ No newline at end of file