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authorGrant Likely <grant.likely@secretlab.ca>2011-04-28 14:27:21 -0600
committerGrant Likely <grant.likely@secretlab.ca>2011-05-23 09:30:20 -0600
commit93c02ab40ae6e06cb24d14845d9f008fdd24f43d (patch)
treea8caf072ce7409eceb8178e952b7536bbd289460 /arch/arm/kernel/setup.c
parent6291319d4864848efc7b5d81389e2404fb478cb9 (diff)
downloadtalos-obmc-linux-93c02ab40ae6e06cb24d14845d9f008fdd24f43d.tar.gz
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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>
Diffstat (limited to 'arch/arm/kernel/setup.c')
-rw-r--r--arch/arm/kernel/setup.c23
1 files changed, 19 insertions, 4 deletions
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 42c2f0cedf1b..05db25ef3dd5 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -20,6 +20,7 @@
#include <linux/screen_info.h>
#include <linux/init.h>
#include <linux/kexec.h>
+#include <linux/of_fdt.h>
#include <linux/crash_dump.h>
#include <linux/root_dev.h>
#include <linux/cpu.h>
@@ -42,6 +43,7 @@
#include <asm/cachetype.h>
#include <asm/tlbflush.h>
+#include <asm/prom.h>
#include <asm/mach/arch.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
@@ -309,7 +311,7 @@ static void __init cacheid_init(void)
*/
extern struct proc_info_list *lookup_processor_type(unsigned int);
-static void __init early_print(const char *str, ...)
+void __init early_print(const char *str, ...)
{
extern void printascii(const char *);
char buf[256];
@@ -439,7 +441,7 @@ void cpu_init(void)
: "r14");
}
-static void __init dump_machine_table(void)
+void __init dump_machine_table(void)
{
struct machine_desc *p;
@@ -837,8 +839,17 @@ static struct machine_desc * __init setup_machine_tags(unsigned int nr)
if (tags->hdr.tag != ATAG_CORE)
convert_to_tag_list(tags);
#endif
- if (tags->hdr.tag != ATAG_CORE)
+
+ if (tags->hdr.tag != ATAG_CORE) {
+#if defined(CONFIG_OF)
+ /*
+ * If CONFIG_OF is set, then assume this is a reasonably
+ * modern system that should pass boot parameters
+ */
+ early_print("Warning: Neither atags nor dtb found\n");
+#endif
tags = (struct tag *)&init_tags;
+ }
if (mdesc->fixup)
mdesc->fixup(mdesc, tags, &from, &meminfo);
@@ -864,7 +875,9 @@ void __init setup_arch(char **cmdline_p)
unwind_init();
setup_processor();
- mdesc = setup_machine_tags(machine_arch_type);
+ mdesc = setup_machine_fdt(__atags_pointer);
+ if (!mdesc)
+ mdesc = setup_machine_tags(machine_arch_type);
machine_desc = mdesc;
machine_name = mdesc->name;
@@ -887,6 +900,8 @@ void __init setup_arch(char **cmdline_p)
paging_init(mdesc);
request_standard_resources(mdesc);
+ unflatten_device_tree();
+
#ifdef CONFIG_SMP
if (is_smp())
smp_init_cpus();
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