Implemented console output for x86 boot loader.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@7029 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kernel/boot/platform/bios_ia32/console.cpp

@@ -0,0 +1,106 @@
+/*
+** Copyright 2004, Axel Dörfler, [email protected]. All rights reserved.
+** Distributed under the terms of the OpenBeOS License.
+*/
+
+
+#include <SupportDefs.h>
+#include <string.h>
+#include <util/kernel_cpp.h>
+
+#include "console.h"
+
+
+class Console : public ConsoleNode {
+	public:
+		Console();
+
+		virtual ssize_t ReadAt(void *cookie, off_t pos, void *buffer, size_t bufferSize);
+		virtual ssize_t WriteAt(void *cookie, off_t pos, const void *buffer, size_t bufferSize);
+};
+
+static uint16 *sScreenBase = (uint16 *)0xb8000;
+static uint32 sScreenWidth = 80;
+static uint32 sScreenHeight = 24;
+static uint32 sScreenOffset = 0;
+
+static Console sInput, sOutput;
+FILE *stdin, *stdout, *stderr;
+
+
+static void
+clear_screen()
+{
+	for (uint32 i = 0; i < sScreenWidth * sScreenHeight; i++)
+		sScreenBase[i] = 0xf20;
+}
+
+
+static void
+scroll_up()
+{
+	memcpy(sScreenBase, sScreenBase + sScreenWidth,
+		sScreenWidth * sScreenHeight * 2 - sScreenWidth * 2);
+	sScreenOffset = (sScreenHeight - 1) * sScreenWidth;
+
+	for (uint32 i = 0; i < sScreenWidth; i++)
+		sScreenBase[sScreenOffset + i] = 0x0720;
+}
+
+
+//	#pragma mark -
+
+
+Console::Console()
+	: ConsoleNode()
+{
+}
+
+
+ssize_t
+Console::ReadAt(void *cookie, off_t pos, void *buffer, size_t bufferSize)
+{
+	// don't seek in character devices
+	// not implemented (and not yet? needed)
+	return B_ERROR;
+}
+
+
+ssize_t
+Console::WriteAt(void *cookie, off_t /*pos*/, const void *buffer, size_t bufferSize)
+{
+	const char *string = (const char *)buffer;
+
+	for (uint32 i = 0; i < bufferSize; i++) {
+		if (string[0] == '\n')
+			sScreenOffset += sScreenWidth - (sScreenOffset % sScreenWidth);
+		else
+			sScreenBase[sScreenOffset++] = 0xf00 | string[0];
+
+		if (sScreenOffset >= sScreenWidth * sScreenHeight)
+			scroll_up();
+
+		string++;
+	}
+	return bufferSize;
+}
+
+
+//	#pragma mark -
+
+
+status_t
+console_init(void)
+{
+	// ToDo: make screen size changeable via stage2_args
+
+	clear_screen();
+
+	// enable stdio functionality
+	stdin = (FILE *)&sInput;
+	stdout = stderr = (FILE *)&sOutput;
+
+	return B_OK;
+}
+
+

src/kernel/boot/platform/bios_ia32/console.h

@@ -0,0 +1,22 @@
+/*
+** Copyright 2004, Axel Dörfler, [email protected]. All rights reserved.
+** Distributed under the terms of the OpenBeOS License.
+*/
+#ifndef CONSOLE_H
+#define CONSOLE_H
+
+
+#include <boot/vfs.h>
+#include <boot/stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern status_t console_init(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* CONSOLE_H */