From 60a463c6739ca7240f62f0b5f697c081cfdf6f9c Mon Sep 17 00:00:00 2001
From: Ingo Weinhold <ingo_weinhold@gmx.de>
Date: Sat, 15 Jan 2005 21:36:50 +0000
Subject: [PATCH] Added /dev/dprintf driver. It's probably quite different from
 R5's, but nevertheless useful for debugging.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@10757 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/add-ons/kernel/drivers/common/Jamfile     |   4 +
 src/add-ons/kernel/drivers/common/dprintf.cpp | 168 ++++++++++++++++++
 2 files changed, 172 insertions(+)
 create mode 100644 src/add-ons/kernel/drivers/common/dprintf.cpp

diff --git a/src/add-ons/kernel/drivers/common/Jamfile b/src/add-ons/kernel/drivers/common/Jamfile
index 2e2291d9f0..27e0a3255a 100644
--- a/src/add-ons/kernel/drivers/common/Jamfile
+++ b/src/add-ons/kernel/drivers/common/Jamfile
@@ -1,5 +1,9 @@
 SubDir OBOS_TOP src add-ons kernel drivers common ;
 
+KernelAddon dprintf : kernel drivers dev :
+	dprintf.cpp
+	;
+
 KernelAddon null : kernel drivers dev :
 	null.c
 	;
diff --git a/src/add-ons/kernel/drivers/common/dprintf.cpp b/src/add-ons/kernel/drivers/common/dprintf.cpp
new file mode 100644
index 0000000000..b8756383f4
--- /dev/null
+++ b/src/add-ons/kernel/drivers/common/dprintf.cpp
@@ -0,0 +1,168 @@
+/*
+ * Copyright 2005, Haiku Inc. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ *
+ * Author(s):
+ *   Ingo Weinhold <bonefish@users.sourceforge.net>
+ *
+ * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
+ * Distributed under the terms of the NewOS License.
+ */
+
+
+#include <string.h>
+
+#include <debug.h>
+
+#include <Drivers.h>
+#include <KernelExport.h>
+
+
+
+#define DEVICE_NAME "dprintf"
+
+int32 api_version = B_CUR_DRIVER_API_VERSION;
+
+
+static status_t
+dprintf_open(const char *name, uint32 flags, void **cookie)
+{
+	*cookie = NULL;
+	return B_OK;
+}
+
+
+static status_t
+dprintf_close(void *cookie)
+{
+	return B_OK;
+}
+
+
+static status_t
+dprintf_freecookie(void *cookie)
+{
+	return B_OK;
+}
+
+
+static status_t
+dprintf_ioctl(void *cookie, uint32 op, void *buffer, size_t length)
+{
+	return EPERM;
+}
+
+
+static status_t
+dprintf_read(void *cookie, off_t pos, void *buffer, size_t *length)
+{
+	*length = 0;
+	return B_OK;
+}
+
+
+static status_t
+dprintf_write(void *cookie, off_t pos, const void *buffer, size_t *_length)
+{
+	const char *str = (const char*)buffer;
+
+	int bytesLeft = *_length;
+	while (bytesLeft > 0) {
+		int chunkSize = strnlen(str, bytesLeft);
+		if (chunkSize == 0) {
+			// null bytes -- skip
+			str++;
+			bytesLeft--;
+			continue;
+		}
+
+		if (chunkSize == bytesLeft) {
+			// no null-byte in the remainder of the buffer
+			// we need to copy to a local buffer and null-terminate
+			while (bytesLeft > 0) {
+				chunkSize = bytesLeft;
+
+				char localBuffer[512];
+				if (bytesLeft > (int)sizeof(localBuffer) - 1)
+					chunkSize = (int)sizeof(localBuffer) - 1;
+				memcpy(localBuffer, str, chunkSize);
+				localBuffer[chunkSize] = '\0';
+
+				dbg_puts(localBuffer);
+
+				str += chunkSize;
+				bytesLeft -= chunkSize;
+			}
+		} else {
+			// null-terminated chunk -- just write it
+			dbg_puts(str);
+
+			str += chunkSize + 1;
+			bytesLeft -= chunkSize + 1;
+		}
+	}
+
+	return B_OK;
+}
+
+
+//	#pragma mark -
+
+
+status_t
+init_hardware(void)
+{
+	return B_OK;
+}
+
+
+const char **
+publish_devices(void)
+{
+	static const char *devices[] = {
+		DEVICE_NAME, 
+		NULL
+	};
+
+	return devices;
+}
+
+
+device_hooks *
+find_device(const char *name)
+{
+	static device_hooks hooks = {
+		&dprintf_open,
+		&dprintf_close,
+		&dprintf_freecookie,
+		&dprintf_ioctl,
+		&dprintf_read,
+		&dprintf_write,
+		/* Leave select/deselect/readv/writev undefined. The kernel will
+		 * use its own default implementation. The basic hooks above this
+		 * line MUST be defined, however. */
+		NULL,
+		NULL,
+		NULL,
+		NULL
+	};
+
+	if (!strcmp(name, DEVICE_NAME))
+		return &hooks;
+
+	return NULL;
+}
+
+
+status_t
+init_driver(void)
+{
+	return B_OK;
+}
+
+
+void
+uninit_driver(void)
+{
+}
+