Added usermode interrupt handling

src/x86/context.c

@@ -4,16 +4,27 @@
 #include "heap.h"
 #include "string.h"
 #include "system.h"
+#include <stdarg.h>
+
+void *get_context_pc(struct process_context_t *context)
+{
+    return (void*) context->eip;
+}
 
 void set_context_pc(struct process_context_t *context, void *pc)
 {
-    context->eip = pc;
+    context->eip = (unsigned long) pc;
     context->cs = 0x1B;
 }
 
+void *get_context_stack(struct process_context_t *context)
+{
+    return (void*) context->gp_registers[7];
+}
+
 void set_context_stack(struct process_context_t *context, void *stack)
 {
-    context->gp_registers[7] = stack;
+    context->gp_registers[7] = (unsigned long)stack;
     context->ss = 0x23;
 }
 
@@ -25,4 +36,51 @@ void set_context_flags(struct process_context_t *context, unsigned long flags)
 void set_context_return(struct process_context_t *context, unsigned long value)
 {
     context->gp_registers[0] = value;
+}
+
+void *context_stack_push(struct process_context_t *context, unsigned long value)
+{
+    context->gp_registers[7] -= sizeof(long);
+    *((unsigned long*) context->gp_registers[7]) = value;
+    return (void*) context->gp_registers[7];
+}
+
+void *context_stack_push_struct(struct process_context_t *context, void *data, unsigned long size)
+{
+    context->gp_registers[7] -= size;
+    memcpy((void*) context->gp_registers[7], data, size);
+    return (void*) context->gp_registers[7];
+}
+
+void *context_stack_pop(struct process_context_t *context, void *value)
+{
+    unsigned long *prev_stack = ((unsigned long*) context->gp_registers[7]);
+    context->gp_registers[7] += sizeof(unsigned long);
+    *((unsigned long*) value) = *prev_stack;
+    return (void*) context->gp_registers[7];
+}
+
+void *context_stack_pop_struct(struct process_context_t *context, void *value, unsigned long size)
+{
+    void *prev_stack = ((void*) context->gp_registers[7]);
+    context->gp_registers[7] += size;
+    memcpy(value, prev_stack, size);
+    return (void*) context->gp_registers[7];
+}
+
+void context_call_func(struct process_context_t *context, void *func_ptr, void *ret_ptr, int argc, ...)
+{
+    context->eip = (uint32_t) func_ptr;
+    va_list valist;
+    va_start(valist, argc);
+    for(int i = 0; i < argc; i++)
+    {
+        context_stack_push(context, va_arg(valist, unsigned long));
+    }
+    context_stack_push(context, (unsigned long) ret_ptr);
+}
+
+void context_cleanup_func(struct process_context_t *context, int argc)
+{
+    context->gp_registers[7] -= sizeof(unsigned long) * argc;
 }