Improve task loading

1 files changed, 44 insertions, 0 deletions

diff --git a/src/core/scheduler.c b/src/core/scheduler.c
index 0f2b724..7b1c421 100644
--- a/src/core/scheduler.c
+++ b/src/core/scheduler.c
@@ -1,4 +1,7 @@
 #include "libc/stdio.h"
+#include "gdt.h"
+#include "mem.h"
+#include "paging.h"
 
 char show_tics=0;
 
@@ -17,4 +20,45 @@ void clock(){
       putchar('.');
   }
   schedule();
+}
+
+void run_task(int *page_dir, void *task, int task_size){
+    // Compute various addresses
+    int*pt_addr=PADDR(page_dir[1]);
+    void *entry_point=(void*)(PADDR(pt_addr[3]));
+    void *ustack=(void*)((int)entry_point+0xFF);
+
+    // Load the task into memory
+    memcpy(task,entry_point, task_size);
+  
+    // Load page directory
+    asm(
+      "mov %0, %%eax           \n\t"
+      "mov %%eax,%%cr3         \n\t"
+    :: "b"(page_dir)
+    );
+
+     // Setup users adresses
+ 
+    // Switch to user task
+    asm (
+    "cli                      \n\t" // Ensure we do not get interrupted
+    "movl %%ss, %%eax         \n\t"
+    "movl %%eax, %0           \n\t" // Save kernel ss segment into the TSS
+    "movl %%esp, %1           \n\t" // Save kernel esp into the TSS BEFORE setting up the stack
+    "pushl $0x33              \n\t" // Push task ss which is 0x30 along with prlv which is 0x3
+    "pushl %2                 \n\t" // Push task esp
+    "pushfl                   \n\t" // Retrieve flags
+    "popl %%eax               \n\t"
+    "orl $0x200, %%eax        \n\t" // Enable interrupt for the user task
+    "and $0xffffbfff, %%eax   \n\t" // Clear the NT flags
+    "push %%eax               \n\t" // Push task flags
+    "push $0x23               \n\t" // Push task cs which is 0x20 along with prlv which is 0x3
+    "push %3                  \n\t" // Push task entry point
+    "mov $0x2B, %%eax         \n\t" // GDT entry 0x28 along with prlv which is 0x3
+    "mov %%eax, %%ds          \n\t" // Setting up user data segment
+    "iret                     \n\t" // Launch user task
+    : "=m" (TSS.ss0), "=m" (TSS.esp0)
+    : "b" (ustack), "c" (entry_point)
+  );
 }
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