Syscall to get timer value

3 files changed, 33 insertions, 0 deletions

diff --git a/include/cpu.h b/include/cpu.h
index cccc12b..c15c086 100644
--- a/include/cpu.h
+++ b/include/cpu.h
@@ -82,6 +82,20 @@ static inline void* getirqstack(void)
 #define sys0(sys_n) asm volatile("svc #" syscall_h_expand_and_quote(sys_n) ::: "r0", "r1", "r2", "r3");
 #define sys1(sys_n,arg0) asm volatile("svc #" syscall_h_expand_and_quote(sys_n) ::[r0]"r"(arg0): "r0", "r1", "r2", "r3");
 
+__attribute__((always_inline)) static inline unsigned long long get_sys_time(void)
+{
+	union {
+		struct {
+			unsigned long lo;
+			unsigned long hi;
+		}s;
+		unsigned long long llv;
+	}t;
+	asm volatile("svc #1\nmov %0, r0\nmov %0, r1" : "=r"(t.s.lo), "=r"(t.s.hi));
+	return t.llv;
+}
+
 #define SYS_SCHED 2
+#define SYS_TIME  1
 
 #endif
diff --git a/src/cpu/irq.c b/src/cpu/irq.c
index 24a809c..612b6d8 100644
--- a/src/cpu/irq.c
+++ b/src/cpu/irq.c
@@ -11,6 +11,7 @@
 #include <util/status.h>
 #include <util/time.h>
 
+void utime(void);
 void testfxn(void);
 void handle_data(unsigned char);
 
@@ -109,6 +110,8 @@ void handle_data(unsigned char data)
 		add_thread(uart_scheduler, 0, 2);
 	} else if (data == 0x63) {
 		add_thread(heap_info, 0, 2);
+	} else if (data == 0x64) {
+		add_thread(utime, 0, 2);
 	} else {
 	}
 	g_Drawer.x = 0;
@@ -120,6 +123,16 @@ void handle_data(unsigned char data)
 	write_string(&g_Drawer, "> ");
 }
 
+void utime(void)
+{
+	unsigned long thi, tlo;
+	unsigned long long t = get_sys_time();
+	thi = t >> 32;
+	tlo = t;
+	uart_hex(thi);
+	uart_hexn(tlo);
+}
+
 void testfxn2(void)
 {
 	uart_string("Ran testfxn2\n");
diff --git a/src/exceptions/svc.S b/src/exceptions/svc.S
index d1fcbc0..51c6479 100644
--- a/src/exceptions/svc.S
+++ b/src/exceptions/svc.S
@@ -18,6 +18,12 @@ svc_000000:
 	cps #0x13
 	b svc_exit
 svc_000001:
+	mov r2, #0x3004
+	movt r2, #0x3F00
+	ldr r0, [r2, #4] // <- SYS_TIMER_CLO
+	ldr r1, [r2, #0] // <- SYS_TIMER_CHI
+	str r0, [sp]	 // Return value
+	str r1, [sp, #4] // Return value hi
 	b svc_exit
 svc_000002:
 	ldmfd sp!, {r0-r12,lr}