Prepare for user memory management and usermode code

3 files changed, 16 insertions, 4 deletions

diff --git a/src/kernel/include/paging.h b/src/kernel/include/paging.h
index d42ec52..56fa7fa 100644
--- a/src/kernel/include/paging.h
+++ b/src/kernel/include/paging.h
@@ -3,10 +3,16 @@
 #include <sys.h>
 #include <stdbool.h>
 
+// Bits in the error code for page fault
+#define PF_PRESENT_BIT		(1<<0)
+#define PF_WRITE_BIT		(1<<1)
+#define PF_USER_BIT			(1<<2)
+#define PF_RSVD_WRITE_BIT	(1<<3)
+#define PF_OPFETCH_BIT		(1<<4)
+
 struct page_directory;
 typedef struct page_directory pagedir_t;
 
-
 void paging_setup(void* kernel_data_end);
 
 pagedir_t *get_current_pagedir();
diff --git a/src/kernel/include/region.h b/src/kernel/include/region.h
index 1fef582..a390e06 100644
--- a/src/kernel/include/region.h
+++ b/src/kernel/include/region.h
@@ -8,18 +8,18 @@
 #include <paging.h>
 
 struct region_info;
-typedef void (*page_fault_handler_t)(pagedir_t *pd, struct region_info *r, void* addr);
+typedef void (*kernel_pf_handler_t)(pagedir_t *pd, struct region_info *r, void* addr);
 
 typedef struct region_info {
 	void* addr;
 	size_t size;
 	char* type;
-	page_fault_handler_t pf;
+	kernel_pf_handler_t pf;
 } region_info_t;
 
 void region_allocator_init(void* kernel_data_end);
 
-void* region_alloc(size_t size, char* type, page_fault_handler_t pf);	// returns 0 on error
+void* region_alloc(size_t size, char* type, kernel_pf_handler_t pf);	// returns 0 on error
 region_info_t *find_region(void* addr);
 void region_free(void* addr);
 
diff --git a/src/kernel/include/thread.h b/src/kernel/include/thread.h
index b5fa50d..011067f 100644
--- a/src/kernel/include/thread.h
+++ b/src/kernel/include/thread.h
@@ -3,6 +3,7 @@
 #include <sys.h>
 #include <paging.h>
 #include <region.h>
+#include <idt.h>
 
 #define T_STATE_RUNNING		1
 #define T_STATE_PAUSED	 	2
@@ -12,6 +13,8 @@
 
 #define TASK_SWITCH_FREQUENCY	50		// in herz
 
+typedef void (*user_pf_handler_t)(pagedir_t *pd, registers_t *regs, void* addr);
+
 typedef struct saved_context {
 	uint32_t *esp;
 	void (*eip)();
@@ -27,6 +30,8 @@ typedef struct thread {
 	region_info_t *stack_region;
 
 	struct process *proc;		// process : L1 data structure
+	user_pf_handler_t usermem_pf_handler;	// page fault in user memory
+	isr_handler_t kmem_violation_handler;	// page fault in kernel memory accessed by user code (violation)
 
 	struct thread *next_in_queue;
 } thread_t;
@@ -40,6 +45,7 @@ extern thread_t *current_thread;
 
 void yield();
 void pause();
+void exit();
 
 void resume_thread(thread_t *thread, bool run_at_once);