boot_loader_openfirmware: Implement real_time_clock_usecs()

Partially revert r38465 and move the code from system_time() into a new
real_time_clock_usecs() function. The system_time() implementation was correct
in relying on of_milliseconds(), as pointed out by Axel. Add the correct
function for the desired functionality.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@38481 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/boot/platform/openfirmware/real_time_clock.cpp

@@ -15,7 +15,7 @@
 #include <platform/openfirmware/openfirmware.h>
 
 
-int gRTC = OF_FAILED;
+static int sHandle = OF_FAILED;
 
 
 status_t
@@ -30,8 +30,8 @@ init_real_time_clock(void)
 		return B_ERROR;
 	}
 
-	gRTC = of_open(gKernelArgs.platform_args.rtc_path);
+	sHandle = of_open(gKernelArgs.platform_args.rtc_path);
-	if (gRTC == OF_FAILED) {
+	if (sHandle == OF_FAILED) {
 		printf("%s(): Could not open RTC device!\n", __func__);
 		return B_ERROR;
 	}
@@ -39,3 +39,19 @@ init_real_time_clock(void)
 	return B_OK;
 }
 
+
+bigtime_t
+real_time_clock_usecs(void)
+{
+	if (sHandle == OF_FAILED)
+		return OF_FAILED;
+	int second, minute, hour, day, month, year;
+	if (of_call_method(sHandle, "get-time", 0, 6, &year, &month, &day,
+			&hour, &minute, &second) == OF_FAILED)
+		return OF_FAILED;
+	int days = day;
+		// TODO: Apply algorithm from kernel
+		// to assure monotonically increasing date.
+	return (((days * 24 + hour) * 60ULL + minute) * 60ULL + second)
+		* 1000000ULL;
+}

src/system/boot/platform/openfirmware/real_time_clock.h

@@ -14,9 +14,8 @@
 extern "C" {
 #endif
 
-extern int gRTC;
-
 status_t init_real_time_clock(void);
+bigtime_t real_time_clock_usecs(void);
 
 #ifdef __cplusplus
 }   // extern "C"

src/system/boot/platform/openfirmware/support.cpp

@@ -1,6 +1,5 @@
 /*
  * Copyright 2005, Ingo Weinhold <[email protected]>.
- * Copyright 2010, Andreas Färber <[email protected]>
  * All rights reserved. Distributed under the terms of the MIT License.
  */
 
@@ -9,27 +8,10 @@
 
 #include <platform/openfirmware/openfirmware.h>
 
-#include "real_time_clock.h"
-
 
 bigtime_t
 system_time(void)
 {
-	int milliseconds = of_milliseconds();
+	int result = of_milliseconds();
-	if (milliseconds == OF_FAILED)
+	return (result == OF_FAILED ? 0 : bigtime_t(result) * 1000);
-		milliseconds = 0;
-	bigtime_t result = milliseconds;
-	int second, minute, hour, day, month, year;
-	if (gRTC != OF_FAILED) {
-		if (of_call_method(gRTC, "get-time", 0, 6, &year, &month, &day,
- 				&hour, &minute, &second) != OF_FAILED) {
- 			result %= 1000;
- 			int days = day;
-				// TODO: Apply algorithm from kernel
-				// to assure monotonically increasing date.
- 			result += (((days * 24 + hour) * 60ULL + minute) * 60ULL + second)
-				* 1000ULL;
-		}
-	}
-	return result * 1000;
 }