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microblaze: Final support for statically linked DTB

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If r7 is zero at kernel boot, or does not point to a valid DTB, then
we fall back to a DTB (assumed to be) linked statically in the kernel, instead
of blindly copying bogus cruft into the kernel DTB memory region

Signed-off-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
This commit is contained in:
John Williams 2009-06-22 14:02:09 +10:00 committed by Michal Simek
parent 1170902b34
commit 909964ec89
3 changed files with 26 additions and 15 deletions
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23
arch/microblaze/include/asm/prom.h
View File

@ -16,6 +16,18 @@
#define _ASM_MICROBLAZE_PROM_H
#ifdef __KERNEL__
/* Definitions used by the flattened device tree */
#define OF_DT_HEADER 0xd00dfeed /* marker */
#define OF_DT_BEGIN_NODE 0x1 /* Start of node, full name */
#define OF_DT_END_NODE 0x2 /* End node */
#define OF_DT_PROP 0x3 /* Property: name off, size, content */
#define OF_DT_NOP 0x4 /* nop */
#define OF_DT_END 0x9
#define OF_DT_VERSION 0x10
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/platform_device.h>
@ -29,16 +41,6 @@
#define of_prop_cmp(s1, s2) strcmp((s1), (s2))
#define of_node_cmp(s1, s2) strcasecmp((s1), (s2))
/* Definitions used by the flattened device tree */
#define OF_DT_HEADER 0xd00dfeed /* marker */
#define OF_DT_BEGIN_NODE 0x1 /* Start of node, full name */
#define OF_DT_END_NODE 0x2 /* End node */
#define OF_DT_PROP 0x3 /* Property: name off, size, content */
#define OF_DT_NOP 0x4 /* nop */
#define OF_DT_END 0x9
#define OF_DT_VERSION 0x10
/*
* This is what gets passed to the kernel by prom_init or kexec
*
@ -309,5 +311,6 @@ extern void __iomem *of_iomap(struct device_node *device, int index);
*/
#include <linux/of.h>
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _ASM_MICROBLAZE_PROM_H */

15
arch/microblaze/kernel/head.S
View File

@ -31,6 +31,7 @@
#include <linux/linkage.h>
#include <asm/thread_info.h>
#include <asm/page.h>
#include <asm/prom.h> /* for OF_DT_HEADER */
#ifdef CONFIG_MMU
#include <asm/setup.h> /* COMMAND_LINE_SIZE */
@ -54,11 +55,16 @@ ENTRY(_start)
andi r1, r1, ~2
mts rmsr, r1
/* save fdt to kernel location */
/* r7 stores pointer to fdt blob */
beqi r7, no_fdt_arg
/* r7 may point to an FDT, or there may be one linked in.
if it's in r7, we've got to save it away ASAP.
We ensure r7 points to a valid FDT, just in case the bootloader
is broken or non-existent */
beqi r7, no_fdt_arg /* NULL pointer? don't copy */
lw r11, r0, r7 /* Does r7 point to a */
rsubi r11, r11, OF_DT_HEADER /* valid FDT? */
bnei r11, no_fdt_arg /* No - get out of here */
or r11, r0, r0 /* incremment */
ori r4, r0, TOPHYS(_fdt_start) /* save bram context */
ori r4, r0, TOPHYS(_fdt_start)
ori r3, r0, (0x4000 - 4)
_copy_fdt:
lw r12, r7, r11 /* r12 = r7 + r11 */
@ -67,6 +73,7 @@ _copy_fdt:
bgtid r3, _copy_fdt /* loop for all entries */
addik r3, r3, -4 /* descrement loop */
no_fdt_arg:
add r7, r0, r0 /* Clear r7, just to be sure */
#ifdef CONFIG_MMU

3
arch/microblaze/kernel/setup.c
View File

@ -139,7 +139,8 @@ void __init machine_early_init(const char *cmdline, unsigned int ram,
#endif
early_printk("Ramdisk addr 0x%08x, FDT 0x%08x\n", ram, fdt);
printk(KERN_NOTICE "Found FDT at 0x%08x\n", fdt);
if(fdt)
printk(KERN_NOTICE "Found FDT at 0x%08x\n", fdt);
#ifdef CONFIG_MTD_UCLINUX
early_printk("Found romfs @ 0x%08x (0x%08x)\n",