m68knommu: move ColdFire head.S to its own coldfire directory

Move common ColdFire CPU head.S to common coldfire platform directory.

Currently the common ColdFire CPU family code sits in the
arch/m68knommu/platform/5307 directory. This is confusing, the files
containing this common code are in no way specific to the 5307 ColdFire.
Create an arch/m68knommu/platform/coldfire directory to contain this
common code. Other m68knommu CPU varients do not need use this code
though, so it doesn't make sense to move it to arch/m68knommu/kernel.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 222 insertions, 0 deletions

diff --git a/arch/m68knommu/platform/coldfire/head.S b/arch/m68knommu/platform/coldfire/head.S
new file mode 100644
index 000000000000..b9aa0ca29bfb
--- /dev/null
+++ b/arch/m68knommu/platform/coldfire/head.S
@@ -0,0 +1,222 @@
+/*****************************************************************************/
+
+/*
+ *	head.S -- common startup code for ColdFire CPUs.
+ *
+ *	(C) Copyright 1999-2006, Greg Ungerer <gerg@snapgear.com>.
+ */
+
+/*****************************************************************************/
+
+#include <linux/sys.h>
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/coldfire.h>
+#include <asm/mcfcache.h>
+#include <asm/mcfsim.h>
+
+/*****************************************************************************/
+
+/*
+ *	If we don't have a fixed memory size, then lets build in code
+ *	to auto detect the DRAM size. Obviously this is the prefered
+ *	method, and should work for most boards. It won't work for those
+ *	that do not have their RAM starting at address 0, and it only
+ *	works on SDRAM (not boards fitted with SRAM).
+ */
+#if CONFIG_RAMSIZE != 0
+.macro GET_MEM_SIZE
+	movel	#CONFIG_RAMSIZE,%d0	/* hard coded memory size */
+.endm
+
+#elif defined(CONFIG_M5206) || defined(CONFIG_M5206e) || \
+      defined(CONFIG_M5249) || defined(CONFIG_M527x) || \
+      defined(CONFIG_M528x) || defined(CONFIG_M5307) || \
+      defined(CONFIG_M5407)
+/*
+ *	Not all these devices have exactly the same DRAM controller,
+ *	but the DCMR register is virtually identical - give or take
+ *	a couple of bits. The only exception is the 5272 devices, their
+ *	DRAM controller is quite different.
+ */
+.macro GET_MEM_SIZE
+	movel	MCF_MBAR+MCFSIM_DMR0,%d0 /* get mask for 1st bank */
+	btst	#0,%d0			/* check if region enabled */
+	beq	1f
+	andl	#0xfffc0000,%d0
+	beq	1f
+	addl	#0x00040000,%d0		/* convert mask to size */
+1:
+	movel	MCF_MBAR+MCFSIM_DMR1,%d1 /* get mask for 2nd bank */
+	btst	#0,%d1			/* check if region enabled */
+	beq	2f
+	andl	#0xfffc0000, %d1
+	beq	2f
+	addl	#0x00040000,%d1
+	addl	%d1,%d0			/* total mem size in d0 */
+2:
+.endm
+
+#elif defined(CONFIG_M5272)
+.macro GET_MEM_SIZE
+	movel	MCF_MBAR+MCFSIM_CSOR7,%d0 /* get SDRAM address mask */
+	andil	#0xfffff000,%d0		/* mask out chip select options */
+	negl	%d0			/* negate bits */
+.endm
+
+#elif defined(CONFIG_M520x)
+.macro GET_MEM_SIZE
+	clrl	%d0
+	movel	MCF_MBAR+MCFSIM_SDCS0, %d2 /* Get SDRAM chip select 0 config */
+	andl	#0x1f, %d2		/* Get only the chip select size */
+	beq	3f			/* Check if it is enabled */
+	addql	#1, %d2			/* Form exponent */
+	moveql	#1, %d0
+	lsll	%d2, %d0		/* 2 ^ exponent */
+3:
+	movel	MCF_MBAR+MCFSIM_SDCS1, %d2 /* Get SDRAM chip select 1 config */
+	andl	#0x1f, %d2		/* Get only the chip select size */
+	beq	4f			/* Check if it is enabled */
+	addql	#1, %d2			/* Form exponent */
+	moveql	#1, %d1
+	lsll	%d2, %d1		/* 2 ^ exponent */
+	addl	%d1, %d0		/* Total size of SDRAM in d0 */
+4:
+.endm
+
+#else
+#error "ERROR: I don't know how to probe your boards memory size?"
+#endif
+
+/*****************************************************************************/
+
+/*
+ *	Boards and platforms can do specific early hardware setup if
+ *	they need to. Most don't need this, define away if not required.
+ */
+#ifndef PLATFORM_SETUP
+#define	PLATFORM_SETUP
+#endif
+
+/*****************************************************************************/
+
+.global	_start
+.global _rambase
+.global _ramvec
+.global	_ramstart
+.global	_ramend
+
+/*****************************************************************************/
+
+.data
+
+/*
+ *	During startup we store away the RAM setup. These are not in the
+ *	bss, since their values are determined and written before the bss
+ *	has been cleared.
+ */
+_rambase:
+.long	0
+_ramvec:
+.long	0
+_ramstart:
+.long	0
+_ramend:
+.long	0
+
+/*****************************************************************************/
+
+.text
+
+/*
+ *	This is the codes first entry point. This is where it all
+ *	begins...
+ */
+
+_start:
+	nop					/* filler */
+	movew	#0x2700, %sr			/* no interrupts */
+
+	/*
+	 *	Do any platform or board specific setup now. Most boards
+	 *	don't need anything. Those exceptions are define this in
+	 *	their board specific includes.
+	 */
+	PLATFORM_SETUP
+
+	/*
+	 *	Create basic memory configuration. Set VBR accordingly,
+	 *	and size memory.
+	 */
+	movel	#CONFIG_VECTORBASE,%a7
+	movec   %a7,%VBR			/* set vectors addr */
+	movel	%a7,_ramvec
+
+	movel	#CONFIG_RAMBASE,%a7		/* mark the base of RAM */
+	movel	%a7,_rambase
+
+	GET_MEM_SIZE				/* macro code determines size */
+	addl	%a7,%d0
+	movel	%d0,_ramend			/* set end ram addr */
+
+	/*
+	 *	Now that we know what the memory is, lets enable cache
+	 *	and get things moving. This is Coldfire CPU specific.
+	 */
+	CACHE_ENABLE				/* enable CPU cache */
+
+
+#ifdef CONFIG_ROMFS_FS
+	/*
+	 *	Move ROM filesystem above bss :-)
+	 */
+	lea	_sbss,%a0			/* get start of bss */
+	lea	_ebss,%a1			/* set up destination  */
+	movel	%a0,%a2				/* copy of bss start */
+
+	movel	8(%a0),%d0			/* get size of ROMFS */
+	addql	#8,%d0				/* allow for rounding */
+	andl	#0xfffffffc, %d0		/* whole words */
+
+	addl	%d0,%a0				/* copy from end */
+	addl	%d0,%a1				/* copy from end */
+	movel	%a1,_ramstart			/* set start of ram */
+
+_copy_romfs:
+	movel	-(%a0),%d0			/* copy dword */
+	movel	%d0,-(%a1)
+	cmpl	%a0,%a2				/* check if at end */
+	bne	_copy_romfs
+
+#else /* CONFIG_ROMFS_FS */
+	lea	_ebss,%a1
+	movel	%a1,_ramstart
+#endif /* CONFIG_ROMFS_FS */
+
+
+	/*
+	 *	Zero out the bss region.
+	 */
+	lea	_sbss,%a0			/* get start of bss */
+	lea	_ebss,%a1			/* get end of bss */
+	clrl	%d0				/* set value */
+_clear_bss:
+	movel	%d0,(%a0)+			/* clear each word */
+	cmpl	%a0,%a1				/* check if at end */
+	bne	_clear_bss
+
+	/*
+	 *	Load the current task pointer and stack.
+	 */
+	lea	init_thread_union,%a0
+	lea	THREAD_SIZE(%a0),%sp
+
+	/*
+	 *	Assember start up done, start code proper.
+	 */
+	jsr	start_kernel			/* start Linux kernel */
+
+_exit:
+	jmp	_exit				/* should never get here */
+
+/*****************************************************************************/