m68k/atari: Initial ARAnyM support

Add improved support for running under the ARAnyM emulator
(Atari Running on Any Machine - http://aranym.org/).

[michael, geert: Cleanups and updates]
Signed-off-by: Petr Stehlik <pstehlik@sophics.cz>
Signed-off-by: Michael Schmitz <schmitz@debian.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/Kconfig

@@ -240,6 +240,13 @@ config SUN3
 
 	  If you don't want to compile a kernel exclusively for a Sun 3, say N.
 
+config NATFEAT
+	bool "ARAnyM emulator support"
+	depends on ATARI
+	help
+	  This option enables support for ARAnyM native features, such as
+	  access to a disk image as /dev/hda.
+
 comment "Processor type"
 
 config M68020

arch/m68k/Makefile

@@ -76,6 +76,7 @@ core-$(CONFIG_MVME16x)		+= arch/m68k/mvme16x/
 core-$(CONFIG_BVME6000)		+= arch/m68k/bvme6000/
 core-$(CONFIG_SUN3X)		+= arch/m68k/sun3x/	arch/m68k/sun3/
 core-$(CONFIG_SUN3)		+= arch/m68k/sun3/	arch/m68k/sun3/prom/
+core-$(CONFIG_NATFEAT)		+= arch/m68k/emu/
 core-$(CONFIG_M68040)		+= arch/m68k/fpsp040/
 core-$(CONFIG_M68060)		+= arch/m68k/ifpsp060/
 core-$(CONFIG_M68KFPU_EMU)	+= arch/m68k/math-emu/

arch/m68k/emu/Makefile

+#
+# Makefile for Linux arch/m68k/emu source directory
+#
+
+obj-y			+= natfeat.o

arch/m68k/emu/natfeat.c

+/*
+ * natfeat.c - ARAnyM hardware support via Native Features (natfeats)
+ *
+ * Copyright (c) 2005 Petr Stehlik of ARAnyM dev team
+ *
+ * Reworked for Linux by Roman Zippel <zippel@linux-m68k.org>
+ *
+ * This software may be used and distributed according to the terms of
+ * the GNU General Public License (GPL), incorporated herein by reference.
+ */
+
+#include <linux/types.h>
+#include <linux/console.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <asm/machdep.h>
+#include <asm/natfeat.h>
+
+asm("\n"
+"	.global nf_get_id,nf_call\n"
+"nf_get_id:\n"
+"	.short	0x7300\n"
+"	rts\n"
+"nf_call:\n"
+"	.short	0x7301\n"
+"	rts\n"
+"1:	moveq.l	#0,%d0\n"
+"	rts\n"
+"	.section __ex_table,\"a\"\n"
+"	.long	nf_get_id,1b\n"
+"	.long	nf_call,1b\n"
+"	.previous");
+EXPORT_SYMBOL_GPL(nf_get_id);
+EXPORT_SYMBOL_GPL(nf_call);
+
+static int stderr_id;
+
+static void nf_write(struct console *co, const char *str, unsigned int count)
+{
+	char buf[68];
+
+	buf[64] = 0;
+	while (count > 64) {
+		memcpy(buf, str, 64);
+		nf_call(stderr_id, buf);
+		str += 64;
+		count -= 64;
+	}
+	memcpy(buf, str, count);
+	buf[count] = 0;
+	nf_call(stderr_id, buf);
+}
+
+void nfprint(const char *fmt, ...)
+{
+	static char buf[256];
+	va_list ap;
+	int n;
+
+	va_start(ap, fmt);
+	n = vsnprintf(buf, 256, fmt, ap);
+	nf_call(nf_get_id("NF_STDERR"), buf);
+	va_end(ap);
+}
+
+static struct console nf_console_driver = {
+	.name	= "debug",
+	.write	= nf_write,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+};
+
+static int __init nf_debug_setup(char *arg)
+{
+	if (strcmp(arg, "emu"))
+		return 0;
+
+	stderr_id = nf_get_id("NF_STDERR");
+	if (stderr_id)
+		register_console(&nf_console_driver);
+	return 0;
+}
+
+early_param("debug", nf_debug_setup);
+
+static void nf_poweroff(void)
+{
+	long id = nf_get_id("NF_SHUTDOWN");
+
+	if (id)
+		nf_call(id);
+}
+
+void nf_init(void)
+{
+	unsigned long id, version;
+	char buf[256];
+
+	id = nf_get_id("NF_VERSION");
+	if (!id)
+		return;
+	version = nf_call(id);
+
+	id = nf_get_id("NF_NAME");
+	if (!id)
+		return;
+	nf_call(id, buf, 256);
+	buf[255] = 0;
+
+	pr_info("NatFeats found (%s, %lu.%lu)\n", buf, version >> 16,
+		version & 0xffff);
+
+	mach_power_off = nf_poweroff;
+}

arch/m68k/include/asm/natfeat.h

+/*
+ * ARAnyM hardware support via Native Features (natfeats)
+ *
+ * Copyright (c) 2005 Petr Stehlik of ARAnyM dev team
+ *
+ * This software may be used and distributed according to the terms of
+ * the GNU General Public License (GPL), incorporated herein by reference.
+ */
+
+#ifndef _NATFEAT_H
+#define _NATFEAT_H
+
+long nf_get_id(const char *feature_name);
+long nf_call(long id, ...);
+
+void nf_init(void);
+void nf_shutdown(void);
+
+void nfprint(const char *fmt, ...)
+	__attribute__ ((format (printf, 1, 2)));
+
+# endif /* _NATFEAT_H */

arch/m68k/kernel/setup.c

@@ -42,6 +42,7 @@
 #ifdef CONFIG_SUN3X
 #include <asm/dvma.h>
 #endif
+#include <asm/natfeat.h>
 
 #if !FPSTATESIZE || !NR_IRQS
 #warning No CPU/platform type selected, your kernel will not work!
@@ -324,6 +325,10 @@ void __init setup_arch(char **cmdline_p)
 		panic("No configuration setup");
 	}
 
+#ifdef CONFIG_NATFEAT
+	nf_init();
+#endif
+
 	paging_init();
 
 #ifndef CONFIG_SUN3