alistair23-linux/arch/arm/include/asm/prom.h
Grant Likely 93c02ab40a arm/dt: probe for platforms via the device tree
If a dtb is passed to the kernel then the kernel needs to iterate
through compiled-in mdescs looking for one that matches and move the
dtb data to a safe location before it gets accidentally overwritten by
the kernel.

This patch creates a new function, setup_machine_fdt() which is
analogous to the setup_machine_atags() created in the previous patch.
It does all the early setup needed to use a device tree machine
description.

v5: - Print warning with neither dtb nor atags are passed to the kernel
    - Fix bug in setting of __machine_arch_type to the selected machine,
      not just the last machine in the list.
      Reported-by: Tixy <tixy@yxit.co.uk>
    - Copy command line directly into boot_command_line instead of cmd_line
v4: - Dump some output when a matching machine_desc cannot be found
v3: - Added processing of reserved list.
    - Backed out the v2 change that copied instead of reserved the
      dtb.  dtb is reserved again and the real problem was fixed by
      using alloc_bootmem_align() for early allocation of RAM for
      unflattening the tree.
    - Moved cmd_line and initrd changes to earlier patch to make series
      bisectable.
v2: Changed to save the dtb by copying into an allocated buffer.
    - Since the dtb will very likely be passed in the first 16k of ram
      where the interrupt vectors live, memblock_reserve() is
      insufficient to protect the dtb data.

[based on work originally written by Jeremy Kerr <jeremy.kerr@canonical.com>]
Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-23 09:30:20 -06:00

38 lines
819 B
C

/*
* arch/arm/include/asm/prom.h
*
* Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
*
* 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 __ASMARM_PROM_H
#define __ASMARM_PROM_H
#ifdef CONFIG_OF
#include <asm/setup.h>
#include <asm/irq.h>
static inline void irq_dispose_mapping(unsigned int virq)
{
return;
}
extern struct machine_desc *setup_machine_fdt(unsigned int dt_phys);
extern void arm_dt_memblock_reserve(void);
#else /* CONFIG_OF */
static inline struct machine_desc *setup_machine_fdt(unsigned int dt_phys)
{
return NULL;
}
static inline void arm_dt_memblock_reserve(void) { }
#endif /* CONFIG_OF */
#endif /* ASMARM_PROM_H */