From 909964ec89ba466d75d53250d5738d1891cc1a3d Mon Sep 17 00:00:00 2001 From: John Williams Date: Mon, 22 Jun 2009 14:02:09 +1000 Subject: [PATCH] microblaze: Final support for statically linked DTB 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 Signed-off-by: Michal Simek --- arch/microblaze/include/asm/prom.h | 23 +++++++++++++---------- arch/microblaze/kernel/head.S | 15 +++++++++++---- arch/microblaze/kernel/setup.c | 3 ++- 3 files changed, 26 insertions(+), 15 deletions(-) diff --git a/arch/microblaze/include/asm/prom.h b/arch/microblaze/include/asm/prom.h index 20f7b3a926e8..37e6f305a68e 100644 --- a/arch/microblaze/include/asm/prom.h +++ b/arch/microblaze/include/asm/prom.h @@ -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 #include #include @@ -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 +#endif /* __ASSEMBLY__ */ #endif /* __KERNEL__ */ #endif /* _ASM_MICROBLAZE_PROM_H */ diff --git a/arch/microblaze/kernel/head.S b/arch/microblaze/kernel/head.S index e568d6ec621b..815bcaae99c3 100644 --- a/arch/microblaze/kernel/head.S +++ b/arch/microblaze/kernel/head.S @@ -31,6 +31,7 @@ #include #include #include +#include /* for OF_DT_HEADER */ #ifdef CONFIG_MMU #include /* 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 diff --git a/arch/microblaze/kernel/setup.c b/arch/microblaze/kernel/setup.c index 8709bea09604..59a383621b22 100644 --- a/arch/microblaze/kernel/setup.c +++ b/arch/microblaze/kernel/setup.c @@ -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", -- 2.20.1