Add syscall interfaces and task_yield

6 files changed, 105 insertions, 6 deletions

diff --git a/src/include/kernel/syscalls.H b/src/include/kernel/syscalls.H
new file mode 100644
index 000000000..a7a0ef6b7
--- /dev/null
+++ b/src/include/kernel/syscalls.H
@@ -0,0 +1,13 @@
+#ifndef __KERNEL_SYSCALLS_H
+#define __KERNEL_SYSCALLS_H
+
+namespace Systemcalls
+{
+    enum SysCalls
+    {
+	TASK_YIELD = 0,
+
+	SYSCALL_MAX
+    };
+};
+#endif
diff --git a/src/include/sys/syscall.h b/src/include/sys/syscall.h
new file mode 100644
index 000000000..b418b5d15
--- /dev/null
+++ b/src/include/sys/syscall.h
@@ -0,0 +1,25 @@
+#ifndef __SYS_SYSCALL_H
+#define __SYS_SYSCALL_H
+
+#ifdef __cplusplus
+extern "C" 
+{
+#endif
+
+#include <stdint.h>
+
+void* _syscall0(uint64_t);
+void* _syscall1(uint64_t, void*);
+void* _syscall2(uint64_t, void*, void*);
+void* _syscall3(uint64_t, void*, void*, void*);
+void* _syscall4(uint64_t, void*, void*, void*, void*);
+void* _syscall5(uint64_t, void*, void*, void*, void*, void*);
+void* _syscall6(uint64_t, void*, void*, void*, void*, void*, void*);
+void* _syscall7(uint64_t, void*, void*, void*, void*, void*, void*, void*);
+
+#ifdef __cplusplus
+}
+#endif
+
+#include <kernel/syscalls.H>
+#endif
diff --git a/src/kernel/syscall.C b/src/kernel/syscall.C
index 0b591f575..9cabeebd3 100644
--- a/src/kernel/syscall.C
+++ b/src/kernel/syscall.C
@@ -1,13 +1,14 @@
-#include <kernel/console.H>
 #include <kernel/cpu.H>
 #include <kernel/cpumgr.H>
 #include <kernel/scheduler.H>
+#include <kernel/taskmgr.H>
+#include <kernel/task.H>
+#include <kernel/syscalls.H>
+#include <kernel/console.H>
 
 extern "C"
 void kernel_execute_decrementer()
 {
-    //printk("Decrementer.\n");
-
     Scheduler* s = CpuManager::getCurrentCPU()->scheduler;
     s->returnRunnable();
     s->setNextRunnable();
@@ -17,8 +18,42 @@ void kernel_execute_decrementer()
     asm volatile("mtdec %0" :: "r"(decrementer));
 }
 
+namespace Systemcalls
+{
+    typedef void(*syscall)(task_t*);
+    void TaskYield(task_t*);
+
+    syscall syscalls[] =
+	{
+	    &TaskYield,
+	};
+};
+
 extern "C"
 void kernel_execute_systemcall()
 {
-    //printk("Syscall.\n");
+    using namespace Systemcalls;
+    task_t* t = TaskManager::getCurrentTask();
+
+    uint64_t syscall = t->context.gprs[3];
+    if (syscall > SYSCALL_MAX)
+    {
+	// TODO : kill task.
+	printk("Invalid syscall : %lld\n", syscall);
+	while(1);
+    }
+    else
+    {
+	syscalls[syscall](t);
+    }
 }
+
+namespace Systemcalls
+{
+    void TaskYield(task_t* t)
+    {
+	Scheduler* s = t->cpu->scheduler;
+	s->returnRunnable();
+	s->setNextRunnable();
+    }
+};
diff --git a/src/lib/makefile b/src/lib/makefile
index b4e27e478..9ea27377e 100644
--- a/src/lib/makefile
+++ b/src/lib/makefile
@@ -1,7 +1,7 @@
 OBJDIR = ../../obj
 include ../../config.mk
 
-OBJS = string.o stdlib.o
+OBJS = string.o stdlib.o syscall_stub.o
 OBJECTS = $(addprefix ${OBJDIR}/, ${OBJS})
 
 all: ${OBJECTS}
diff --git a/src/lib/syscall_stub.S b/src/lib/syscall_stub.S
new file mode 100644
index 000000000..a3b83326e
--- /dev/null
+++ b/src/lib/syscall_stub.S
@@ -0,0 +1,21 @@
+.section .text
+
+.global _syscall0
+.global _syscall1
+.global _syscall2
+.global _syscall3
+.global _syscall4
+.global _syscall5
+.global _syscall6
+.global _syscall7
+
+_syscall0:
+_syscall1:
+_syscall2:
+_syscall3:
+_syscall4:
+_syscall5:
+_syscall6:
+_syscall7:
+    sc
+    blr
diff --git a/src/sys/init/init_main.C b/src/sys/init/init_main.C
index 99a7cfe0b..e2447bc3f 100644
--- a/src/sys/init/init_main.C
+++ b/src/sys/init/init_main.C
@@ -1,8 +1,13 @@
 #include <kernel/console.H>  // TODO : Remove this.
+#include <sys/syscall.h>     // TODO : Remove this.
 
 void init_main(void* unused)
 {
     printk("Starting init!\n");
 
-    while(1);
+    while(1)
+    {
+	_syscall0(Systemcalls::TASK_YIELD);
+	for (volatile int i = 0 ; i < 100000; i++);
+    }
 }