From 2dd799b40682a78945d2e6ab7b30c4585830bdd6 Mon Sep 17 00:00:00 2001
From: Xnoe <xnoe@xnoe.moe>
Date: Sun, 21 Nov 2021 16:56:50 +0000
Subject: [PATCH] Preparations towards context switching

---
 Makefile              |  2 +-
 src/kernel/global.cpp |  3 ++-
 src/kernel/global.h   |  4 ++++
 src/kernel/kernel.cpp | 17 ++++++++++++++---
 src/kernel/kernel.h   | 10 +++++++++-
 src/kernel/kmain.cpp  |  6 +++---
 6 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/Makefile b/Makefile
index 7614b83..116f681 100644
--- a/Makefile
+++ b/Makefile
@@ -13,7 +13,7 @@ run: disk.img
 	qemu-system-x86_64 disk.img
 
 debug: disk.img
-	qemu-system-x86_64 -s -S disk.img & gdb --command=gdbscript
+	qemu-system-x86_64 -s -S -no-reboot -no-shutdown disk.img & gdb --command=gdbscript
 
 disk.img: clean prepare build/boot/boot.bin build/boot_stage2/boot.bin $(DISK_IMG_FILES)
 	dd if=/dev/zero of=disk.img count=43 bs=100k
diff --git a/src/kernel/global.cpp b/src/kernel/global.cpp
index b1096d0..4d42b26 100644
--- a/src/kernel/global.cpp
+++ b/src/kernel/global.cpp
@@ -1,7 +1,8 @@
-#include "memory.h"
+#include "global.h"
 
 namespace Global {
   Allocator* allocator = 0;
+  Kernel* kernel = 0;
 }
 
 void* operator new (uint32_t size) {
diff --git a/src/kernel/global.h b/src/kernel/global.h
index 03cdcc1..78fe794 100644
--- a/src/kernel/global.h
+++ b/src/kernel/global.h
@@ -1,10 +1,14 @@
 #ifndef GLOBAL_H
 #define GLOBAL_H
 
+#include "memory.h"
+
+class Kernel;
 class Allocator;
 
 namespace Global {
   extern Allocator* allocator;
+  extern Kernel* kernel;
 }
 
 void* operator new (uint32_t size);
diff --git a/src/kernel/kernel.cpp b/src/kernel/kernel.cpp
index 777127f..4333bf2 100644
--- a/src/kernel/kernel.cpp
+++ b/src/kernel/kernel.cpp
@@ -1,9 +1,20 @@
 #include "kernel.h"
 
-Kernel* Kernel::kernel;
-
 Kernel::Kernel(PageDirectory* page_directory, PageMap* phys, PageMap* virt, uint32_t virt_alloc_base)
   : Process(0, 0x8a000, page_directory, phys, virt, virt_alloc_base)
 {
-  this->kernel = this;
+  this->currentPID = 1;
+  Global::allocator = this;
+  Global::kernel = this;
+}
+
+void Kernel::init_kernel() {
+  this->pid_map = new xnoe::hashtable<uint32_t, Process*>();
+}
+
+Process* Kernel::createProcess() {
+  Process* p = new Process(currentPID);
+  this->pid_map->set(currentPID, p);
+  currentPID++;
+  return p;
 }
\ No newline at end of file
diff --git a/src/kernel/kernel.h b/src/kernel/kernel.h
index 720f219..aa98294 100644
--- a/src/kernel/kernel.h
+++ b/src/kernel/kernel.h
@@ -2,14 +2,22 @@
 #define KERNEL_H
 
 #include "process.h"
+#include "datatypes/hashtable.h"
+#include "global.h"
 
 class Kernel : public Process {
 private:
-  static Kernel* kernel;
+  uint32_t currentPID;
 
 public:
+  xnoe::hashtable<uint32_t, Process*>* pid_map; // Map of PIDs -> Process*s 
+  uint32_t current_PID;
 
   Kernel(PageDirectory* page_directory, PageMap* phys, PageMap* virt, uint32_t virt_alloc_base);
+
+  void init_kernel();
+
+  Process* createProcess();
 };
 
 #endif
\ No newline at end of file
diff --git a/src/kernel/kmain.cpp b/src/kernel/kmain.cpp
index 1490a27..a5fbbf6 100644
--- a/src/kernel/kmain.cpp
+++ b/src/kernel/kmain.cpp
@@ -28,7 +28,7 @@ int main() {
   PageMap virt_pm(0xc0620000);
 
   Kernel kernel = Kernel(&kernel_pd, &phys_pm, &virt_pm, 0xc0000000);
-  Global::allocator = &kernel;
+  kernel.init_kernel();
 
   Terminal* current_term;
 
@@ -46,8 +46,8 @@ int main() {
   term->printf("Hello, World!\n\nWe are running XnoeOS Code in C++ now, Protected Mode has been achieved (as well as Virtual Memory / Paging!!!) and everything is working super nicely!\n\nHow wonderful!\n\nNow I just need to hope my print function works properly too~~\n");
   
   term->printf("KERNEL OK!\n");
-  
-  Process* process = new Process(1);
+
+  kernel.createProcess();
 
   term->deactivate();
   term2->activate();