sh: Make PAGE_OFFSET configurable.

nommu needs to be able to shift PAGE_OFFSET, so we switch it to a
non-user-visible CONFIG_PAGE_OFFSET and use that in the few places
where it matters.

Signed-off-by: Paul Mundt <[e-mail]>

arch/sh/Kconfig

···
 
 source "arch/sh/mm/Kconfig"
 
-config MEMORY_START
-	hex "Physical memory start address"
-	default "0x08000000"
-	---help---
-	  Computers built with Hitachi SuperH processors always
-	  map the ROM starting at address zero.  But the processor
-	  does not specify the range that RAM takes.
-
-	  The physical memory (RAM) start address will be automatically
-	  set to 08000000. Other platforms, such as the Solution Engine
-	  boards typically map RAM at 0C000000.
-
-	  Tweak this only when porting to a new machine which does not
-	  already have a defconfig. Changing it from the known correct
-	  value on any of the known systems will only lead to disaster.
-
-config MEMORY_SIZE
-	hex "Physical memory size"
-	default "0x00400000"
-	help
-	  This sets the default memory size assumed by your SH kernel. It can
-	  be overridden as normal by the 'mem=' argument on the kernel command
-	  line. If unsure, consult your board specifications or just leave it
-	  as 0x00400000 which was the default value before this became
-	  configurable.
-
 config CF_ENABLER
 	bool "Compact Flash Enabler support"
 	depends on SH_ADX || SH_SOLUTION_ENGINE || SH_UNKNOWN || SH_CAT68701 || SH_SH03

arch/sh/boot/compressed/Makefile

···
 # Assign dummy values if these 2 variables are not defined,
 # in order to suppress error message.
 #
+CONFIG_PAGE_OFFSET	?= 0x80000000
 CONFIG_MEMORY_START     ?= 0x0c000000
 CONFIG_BOOT_LINK_OFFSET ?= 0x00800000
-IMAGE_OFFSET := $(shell printf "0x%8x" $$[0x80000000+$(CONFIG_MEMORY_START)+$(CONFIG_BOOT_LINK_OFFSET)])
+IMAGE_OFFSET := $(shell printf "0x%8x" $$[$(CONFIG_PAGE_OFFSET)+$(CONFIG_MEMORY_START)+$(CONFIG_BOOT_LINK_OFFSET)])
 
 LDFLAGS_vmlinux := -Ttext $(IMAGE_OFFSET) -e startup -T $(obj)/../../kernel/vmlinux.lds
 

arch/sh/kernel/vmlinux.lds.S

···
 ENTRY(_start)
 SECTIONS
 {
-  . = 0x80000000 + CONFIG_MEMORY_START + CONFIG_ZERO_PAGE_OFFSET;
+  . = CONFIG_PAGE_OFFSET + CONFIG_MEMORY_START + CONFIG_ZERO_PAGE_OFFSET;
   _text = .;			/* Text and read-only data */
   text = .;			/* Text and read-only data */
   .empty_zero_page : {

arch/sh/mm/Kconfig

···
 	  turning this off will boot the kernel on these machines with the
 	  MMU implicitly switched off.
 
+config PAGE_OFFSET
+	hex
+	default "0x80000000" if MMU
+	default "0x00000000"
+
+config MEMORY_START
+	hex "Physical memory start address"
+	default "0x08000000"
+	---help---
+	  Computers built with Hitachi SuperH processors always
+	  map the ROM starting at address zero.  But the processor
+	  does not specify the range that RAM takes.
+
+	  The physical memory (RAM) start address will be automatically
+	  set to 08000000. Other platforms, such as the Solution Engine
+	  boards typically map RAM at 0C000000.
+
+	  Tweak this only when porting to a new machine which does not
+	  already have a defconfig. Changing it from the known correct
+	  value on any of the known systems will only lead to disaster.
+
+config MEMORY_SIZE
+	hex "Physical memory size"
+	default "0x00400000"
+	help
+	  This sets the default memory size assumed by your SH kernel. It can
+	  be overridden as normal by the 'mem=' argument on the kernel command
+	  line. If unsure, consult your board specifications or just leave it
+	  as 0x00400000 which was the default value before this became
+	  configurable.
+
 config 32BIT
 	bool "Support 32-bit physical addressing through PMB"
 	depends on CPU_SH4A

include/asm-sh/page.h

···
 #define __MEMORY_START		CONFIG_MEMORY_START
 #define __MEMORY_SIZE		CONFIG_MEMORY_SIZE
 
-#define PAGE_OFFSET		(0x80000000UL)
+#define PAGE_OFFSET		CONFIG_PAGE_OFFSET
 #define __pa(x)			((unsigned long)(x)-PAGE_OFFSET)
 #define __va(x)			((void *)((unsigned long)(x)+PAGE_OFFSET))