From ec7e798c70e54cf10e6dddf465cb7f741f760e79 Mon Sep 17 00:00:00 2001
From: EmulatedSeasons <89668582+EmulatedSeasons@users.noreply.github.com>
Date: Thu, 18 Jan 2024 23:16:56 -0500
Subject: added beginning and end kernel symbols

---
 kernel/arch/i386/boot.asm        | 13 +++++++++++--
 kernel/arch/i386/isr_handler.cpp |  2 +-
 kernel/arch/i386/linker.ld       |  5 +++++
 kernel/kernel.cpp                | 17 ++++++-----------
 kernel/makefile                  |  2 +-
 5 files changed, 24 insertions(+), 15 deletions(-)

(limited to 'kernel')

diff --git a/kernel/arch/i386/boot.asm b/kernel/arch/i386/boot.asm
index b5dfe11..494d3ba 100644
--- a/kernel/arch/i386/boot.asm
+++ b/kernel/arch/i386/boot.asm
@@ -30,10 +30,19 @@ _start:
     ; setup stack
     mov esp, stack_top
 
-    ; get multiboot header data (for memory map)
-    extern multiboot_main
+    ; push the multiboot header data into the stack for later use
     push eax
     push ebx
+
+    ; setup paging (to map kernel to the higher half)
+    ;mov eax, 0
+    ;mov cr3, eax
+    ;mov eax, cr0
+    ;or eax, 0x80000001
+    ;mov cr0, eax
+
+    ; get multiboot header data (for memory map)
+    extern multiboot_main
     call multiboot_main
 
     extern _init
diff --git a/kernel/arch/i386/isr_handler.cpp b/kernel/arch/i386/isr_handler.cpp
index ba825dd..ac8fb49 100644
--- a/kernel/arch/i386/isr_handler.cpp
+++ b/kernel/arch/i386/isr_handler.cpp
@@ -10,7 +10,7 @@
 extern "C" void exception_handler(int e) {
     //unsigned char errorcode[2]{((unsigned char) e) + 48};
     //terminal_initialize();
-	printf("Exception\n");
+	printf("Exception %x\n", e);
 }
 
 #define PS2_DATA 0x60
diff --git a/kernel/arch/i386/linker.ld b/kernel/arch/i386/linker.ld
index 24cfa84..bac95d2 100644
--- a/kernel/arch/i386/linker.ld
+++ b/kernel/arch/i386/linker.ld
@@ -5,6 +5,9 @@ SECTIONS
 {
     . = 1M;
 
+    /* Used to get the beginning and end address of the kernel */
+    _begin = .;
+
     /* code. multiboot header comes first */
     .text BLOCK(4K) : ALIGN(4K)
     {
@@ -30,4 +33,6 @@ SECTIONS
         *(COMMON)
         *(.bss)
     }
+
+    _end = .;
 }
\ No newline at end of file
diff --git a/kernel/kernel.cpp b/kernel/kernel.cpp
index 579e642..877f860 100644
--- a/kernel/kernel.cpp
+++ b/kernel/kernel.cpp
@@ -7,14 +7,10 @@
 #include <arch/i386/ps2_controller.h>
 #include <dev/ps2kbd.h>
 
-// compiler and target check
-#if defined(__linux__)
-#error "you're not using a cross compiler"
-#endif
+// linker symbols
+unsigned int _begin;
+unsigned int _end;
 
-#if !defined(__i386__)
-#error "needs to be compiled using an ix86-elf cross compiler"
-#endif
 
 extern "C" void kernel_main(void) {
     // Initialize terminal
@@ -24,7 +20,6 @@ extern "C" void kernel_main(void) {
     //keyboard_init();
 
     printf("Hello world!\n");
-    printf("among\n");
-    printf("balls\n");
-    printf("a%db", 1);
-}
\ No newline at end of file
+    printf("a%db\n", 1);
+    printf("_begin: %x, _end: %x", &_begin, &_end);
+}
diff --git a/kernel/makefile b/kernel/makefile
index a9407bd..88659d9 100644
--- a/kernel/makefile
+++ b/kernel/makefile
@@ -55,7 +55,7 @@ LINKLST += crtn.o
 
 -include $(DEPFILES)
 
-.PHONY: all crt clean
+.PHONY: all crt clean kernel.bin
 
 all: crti.o crtn.o kernel.bin
 
-- 
cgit v1.2.3-70-g09d2