From 9012ccc49e7a44e4d0922c7d5b2f3648635eb5cc Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Sat, 1 Oct 2022 12:16:30 +0200
Subject: [PATCH] Remove _userspace and move the idle task to assembly

---
 kernel/src/main.asm             | 47 +++++++--------------------------
 kernel/src/thread/Scheduler.cpp | 10 +++----
 2 files changed, 13 insertions(+), 44 deletions(-)

diff --git a/kernel/src/main.asm b/kernel/src/main.asm
index c67ee078..7c5c15f8 100644
--- a/kernel/src/main.asm
+++ b/kernel/src/main.asm
@@ -4,41 +4,14 @@ extern _start
 _main:
     xor rbp, rbp
     call _start
+    cli
+.hang:
+    hlt
+    jmp .hang
 
-global _userspace
-_userspace:
-    mov rdi, 4000 ; 4000 ms / 4 seconds
-    mov rax, 2 ; sys_sleep
-    int 42h
-    cmp rax, 0
-    jne .fail ; syscall failed
-    mov rdi, .message
-    mov rsi, 33
-    mov rax, 3 ; sys_write
-    int 42h
-    cmp rax, 33
-    jne .fail ; syscall did not write enough bytes
-.draw:
-    mov rax, 5 ; sys_rand
-    int 42h
-    mov r9, rax ; color
-    mov rdi, 20 ; x
-    mov rsi, 20 ; y
-    mov r10, 40 ; width
-    mov r8, 30 ; height
-    mov rax, 4 ; sys_paint
-    int 42h
-    cmp rax, 0
-    jne .fail
-    mov rdi, 100
-    mov rax, 2 ; sys_sleep
-    int 42h
-    cmp rax, 0
-    jne .fail
-    jmp .draw
-.fail:
-    mov rax, 0 ; sys_exit
-    int 42h
-    jmp $ ; sys_exit failed, nothing more we can do
-.message:
-    db "userspace preparing for painting", 0xA
\ No newline at end of file
+global idle_task_function
+idle_task_function:
+    sti
+.idle:
+    hlt
+    jmp .idle
\ No newline at end of file
diff --git a/kernel/src/thread/Scheduler.cpp b/kernel/src/thread/Scheduler.cpp
index 46413039..2c5801dc 100644
--- a/kernel/src/thread/Scheduler.cpp
+++ b/kernel/src/thread/Scheduler.cpp
@@ -25,10 +25,7 @@ static Task* sched_current_task;
 static Task* base_task;
 static Task* end_task;
 
-static void idle_task_function()
-{
-    while (1) asm volatile("hlt");
-}
+extern "C" void idle_task_function();
 
 static uint64_t frequency;
 
@@ -36,12 +33,11 @@ void Scheduler::init()
 {
     memset(&idle_task, 0, sizeof(Task));
     idle_task.id = free_tid++;
-    idle_task.regs.rip = (uint64_t)&idle_task_function;
+    idle_task.regs.rip = (uint64_t)idle_task_function;
     idle_task.regs.rsp = (uint64_t)MemoryManager::get_page();
     idle_task.regs.cs = 0x08;
     idle_task.regs.ss = 0x10;
-    asm volatile("pushfq; movq (%%rsp), %%rax; movq %%rax, %0; popfq;" : "=m"(idle_task.regs.rflags)::"%rax");
-    idle_task.regs.rflags |= 0x200;
+    idle_task.regs.rflags = (1 << 21) | (1 << 9);
     idle_task.task_sleep = 1000;
     idle_task.state = idle_task.Idle;