metag: Boot

Add boot code for metag. Due to the multi-threaded nature of Meta it is
not uncommon for an RTOS or bare metal application to be started on
other hardware threads by the bootloader. Since there is a single MMU
switch which affects all threads, the MMU is traditionally configured by
the bootloader prior to starting Linux. The bootloader passes a
structure to Linux which among other things contains information about
memory regions which have been mapped. Linux then assumes control of the
local heap memory region.

A kernel arguments string pointer or a flattened device tree pointer can
be provided in the third argument.

Signed-off-by: James Hogan <james.hogan@imgtec.com>

2 files changed, 90 insertions, 0 deletions

diff --git a/arch/metag/include/asm/mach/arch.h b/arch/metag/include/asm/mach/arch.h
new file mode 100644
index 0000000..6845d80
--- /dev/null
+++ b/arch/metag/include/asm/mach/arch.h
@@ -0,0 +1,82 @@
+/*
+ * arch/metag/include/asm/mach/arch.h
+ *
+ * Copyright (C) 2012 Imagination Technologies Ltd.
+ *
+ * based on the ARM version:
+ *  Copyright (C) 2000 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _METAG_MACH_ARCH_H_
+#define _METAG_MACH_ARCH_H_
+
+#include <linux/stddef.h>
+
+/**
+ * struct machine_desc - Describes a board controlled by a Meta.
+ * @name:		Board/SoC name.
+ * @dt_compat:		Array of device tree 'compatible' strings.
+ *
+ * @nr_irqs:		Maximum number of IRQs.
+ *			If 0, defaults to NR_IRQS in asm-generic/irq.h.
+ *
+ * @init_early:		Early init callback.
+ * @init_irq:		IRQ init callback for setting up IRQ controllers.
+ * @init_machine:	Arch init callback for setting up devices.
+ * @init_late:		Late init callback.
+ *
+ * This structure is provided by each board which can be controlled by a Meta.
+ * It is chosen by matching the compatible strings in the device tree provided
+ * by the bootloader with the strings in @dt_compat, and sets up any aspects of
+ * the machine that aren't configured with device tree (yet).
+ */
+struct machine_desc {
+	const char		*name;
+	const char		**dt_compat;
+
+	unsigned int		nr_irqs;
+
+	void			(*init_early)(void);
+	void			(*init_irq)(void);
+	void			(*init_machine)(void);
+	void			(*init_late)(void);
+};
+
+/*
+ * Current machine - only accessible during boot.
+ */
+extern struct machine_desc *machine_desc;
+
+/*
+ * Machine type table - also only accessible during boot
+ */
+extern struct machine_desc __arch_info_begin[], __arch_info_end[];
+#define for_each_machine_desc(p)			\
+	for (p = __arch_info_begin; p < __arch_info_end; p++)
+
+static inline struct machine_desc *default_machine_desc(void)
+{
+	/* the default machine is the last one linked in */
+	if (__arch_info_end - 1 < __arch_info_begin)
+		return NULL;
+	return __arch_info_end - 1;
+}
+
+/*
+ * Set of macros to define architecture features.  This is built into
+ * a table by the linker.
+ */
+#define MACHINE_START(_type, _name)			\
+static const struct machine_desc __mach_desc_##_type	\
+__used							\
+__attribute__((__section__(".arch.info.init"))) = {	\
+	.name		= _name,
+
+#define MACHINE_END				\
+};
+
+#endif /* _METAG_MACH_ARCH_H_ */
diff --git a/arch/metag/include/asm/setup.h b/arch/metag/include/asm/setup.h
new file mode 100644
index 0000000..e13083b
--- /dev/null
+++ b/arch/metag/include/asm/setup.h
@@ -0,0 +1,8 @@
+#ifndef _ASM_METAG_SETUP_H
+#define _ASM_METAG_SETUP_H
+
+#include <uapi/asm/setup.h>
+
+void per_cpu_trap_init(unsigned long);
+extern void __init dump_machine_table(void);
+#endif /* _ASM_METAG_SETUP_H */