Initial import

1 files changed, 240 insertions, 0 deletions

diff --git a/arch/m68k/68000/head.S b/arch/m68k/68000/head.S
new file mode 100644
index 000000000..536ef9616
--- /dev/null
+++ b/arch/m68k/68000/head.S
@@ -0,0 +1,240 @@
+/*
+ * head.S - Common startup code for 68000 core based CPU's
+ *
+ * 2012.10.21, Luis Alves <ljalvs@gmail.com>, Single head.S file for all
+ *             68000 core based CPU's. Based on the sources from:
+ *             Coldfire by Greg Ungerer <gerg@snapgear.com>
+ *             68328 by D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
+ *                      Kenneth Albanowski <kjahds@kjahds.com>,
+ *                      The Silver Hammer Group, Ltd.
+ *
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/asm-offsets.h>
+#include <asm/thread_info.h>
+
+
+/*****************************************************************************
+ * UCSIMM and UCDIMM use CONFIG_MEMORY_RESERVE to reserve some RAM
+ *****************************************************************************/
+#ifdef CONFIG_MEMORY_RESERVE
+#define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE)-(CONFIG_MEMORY_RESERVE*0x100000)
+#else
+#define RAMEND (CONFIG_RAMBASE+CONFIG_RAMSIZE)
+#endif
+/*****************************************************************************/
+
+.global _start
+.global _rambase
+.global _ramvec
+.global _ramstart
+.global _ramend
+
+#if defined(CONFIG_PILOT) || defined(CONFIG_INIT_LCD)
+.global bootlogo_bits
+#endif
+
+/* Defining DEBUG_HEAD_CODE, serial port in 68x328 is inited */
+/* #define DEBUG_HEAD_CODE */
+#undef DEBUG_HEAD_CODE
+
+.data
+
+/*****************************************************************************
+ * RAM setup pointers. Used by the kernel to determine RAM location and size.
+ *****************************************************************************/
+
+_rambase:
+	.long	0
+_ramvec:
+	.long	0
+_ramstart:
+	.long	0
+_ramend:
+	.long	0
+
+__HEAD
+
+/*****************************************************************************
+ * Entry point, where all begins!
+ *****************************************************************************/
+
+_start:
+
+/* Pilot need this specific signature at the start of ROM */
+#ifdef CONFIG_PILOT
+	.byte	0x4e, 0xfa, 0x00, 0x0a		/* bra opcode (jmp 10 bytes) */
+	.byte	'b', 'o', 'o', 't'
+	.word	10000
+	nop
+	moveq	#0, %d0
+	movew	%d0, 0xfffff618			/* Watchdog off */
+	movel	#0x00011f07, 0xfffff114		/* CS A1 Mask */
+#endif /* CONFIG_PILOT */
+
+	movew	#0x2700, %sr			/* disable all interrupts */
+
+/*****************************************************************************
+ * Setup PLL and wait for it to settle (in 68x328 cpu's).
+ * Also, if enabled, init serial port.
+ *****************************************************************************/
+#if defined(CONFIG_M68328) || \
+    defined(CONFIG_M68EZ328) || \
+    defined(CONFIG_M68VZ328)
+
+/* Serial port setup. Should only be needed if debugging this startup code. */
+#ifdef DEBUG_HEAD_CODE
+	movew	#0x0800, 0xfffff906		/* Ignore CTS */
+	movew	#0x010b, 0xfffff902		/* BAUD to 9600 */
+	movew	#0xe100, 0xfffff900		/* enable */
+#endif /* DEBUG_HEAD */
+
+#ifdef CONFIG_PILOT
+	movew	#0x2410, 0xfffff200		/* PLLCR */
+#else
+	movew	#0x2400, 0xfffff200		/* PLLCR */
+#endif
+	movew	#0x0123, 0xfffff202		/* PLLFSR */
+	moveq	#0, %d0
+	movew	#16384, %d0			/* PLL settle wait loop */
+_pll_settle:
+	subw	#1, %d0
+	bne	_pll_settle
+#endif /* CONFIG_M68x328 */
+
+
+/*****************************************************************************
+ * If running kernel from ROM some specific initialization has to be done.
+ * (Assuming that everything is already init'ed when running from RAM)
+ *****************************************************************************/
+#ifdef CONFIG_ROMKERNEL
+
+/*****************************************************************************
+ * Init chip registers (uCsimm specific)
+ *****************************************************************************/
+#ifdef CONFIG_UCSIMM
+	moveb	#0x00, 0xfffffb0b	/* Watchdog off */
+	moveb	#0x10, 0xfffff000	/* SCR */
+	moveb	#0x00, 0xfffff40b	/* enable chip select */
+	moveb	#0x00, 0xfffff423	/* enable /DWE */
+	moveb	#0x08, 0xfffffd0d	/* disable hardmap */
+	moveb	#0x07, 0xfffffd0e	/* level 7 interrupt clear */
+	movew	#0x8600, 0xfffff100	/* FLASH at 0x10c00000 */
+	movew	#0x018b, 0xfffff110	/* 2Meg, enable, 0ws */
+	movew	#0x8f00, 0xfffffc00	/* DRAM configuration */
+	movew	#0x9667, 0xfffffc02	/* DRAM control */
+	movew	#0x0000, 0xfffff106	/* DRAM at 0x00000000 */
+	movew	#0x068f, 0xfffff116	/* 8Meg, enable, 0ws */
+	moveb	#0x40, 0xfffff300	/* IVR */
+	movel	#0x007FFFFF, %d0	/* IMR */
+	movel	%d0, 0xfffff304
+	moveb	0xfffff42b, %d0
+	andb	#0xe0, %d0
+	moveb	%d0, 0xfffff42b
+#endif
+
+/*****************************************************************************
+ * Init LCD controller.
+ * (Assuming that LCD controller is already init'ed when running from RAM)
+ *****************************************************************************/
+#ifdef CONFIG_INIT_LCD
+#ifdef CONFIG_PILOT
+	moveb	#0, 0xfffffA27			/* LCKCON */
+	movel	#_start, 0xfffffA00		/* LSSA */
+	moveb	#0xa, 0xfffffA05		/* LVPW */
+	movew	#0x9f, 0xFFFFFa08		/* LXMAX */
+	movew	#0x9f, 0xFFFFFa0a		/* LYMAX */
+	moveb	#9, 0xfffffa29			/* LBAR */
+	moveb	#0, 0xfffffa25			/* LPXCD */
+	moveb	#0x04, 0xFFFFFa20		/* LPICF */
+	moveb	#0x58, 0xfffffA27		/* LCKCON */
+	moveb	#0x85, 0xfffff429		/* PFDATA */
+	moveb	#0xd8, 0xfffffA27		/* LCKCON */
+	moveb	#0xc5, 0xfffff429		/* PFDATA */
+	moveb	#0xd5, 0xfffff429		/* PFDATA */
+	movel	#bootlogo_bits, 0xFFFFFA00	/* LSSA */
+	moveb	#10, 0xFFFFFA05			/* LVPW */
+	movew	#160, 0xFFFFFA08		/* LXMAX */
+	movew	#160, 0xFFFFFA0A		/* LYMAX */
+#else /* CONFIG_PILOT */
+	movel	#bootlogo_bits, 0xfffffA00	/* LSSA */
+	moveb	#0x28, 0xfffffA05		/* LVPW */
+	movew	#0x280, 0xFFFFFa08		/* LXMAX */
+	movew	#0x1df, 0xFFFFFa0a		/* LYMAX */
+	moveb	#0, 0xfffffa29			/* LBAR */
+	moveb	#0, 0xfffffa25			/* LPXCD */
+	moveb	#0x08, 0xFFFFFa20		/* LPICF */
+	moveb	#0x01, 0xFFFFFA21		/* -ve pol */
+	moveb	#0x81, 0xfffffA27		/* LCKCON */
+	movew	#0xff00, 0xfffff412		/* LCD pins */
+#endif /* CONFIG_PILOT */
+#endif /* CONFIG_INIT_LCD */
+
+/*****************************************************************************
+ * Kernel is running from FLASH/ROM (XIP)
+ * Copy init text & data to RAM
+ *****************************************************************************/
+	moveal	#_etext, %a0
+	moveal	#_sdata, %a1
+	moveal	#__bss_start, %a2
+_copy_initmem:
+	movel	%a0@+, %a1@+
+	cmpal	%a1, %a2
+	bhi	_copy_initmem
+#endif /* CONFIG_ROMKERNEL */
+
+/*****************************************************************************
+ * Setup basic memory information for kernel
+ *****************************************************************************/
+	movel	#CONFIG_VECTORBASE,_ramvec	/* set vector base location */
+	movel	#CONFIG_RAMBASE,_rambase	/* set the base of RAM */
+	movel	#RAMEND, _ramend		/* set end ram addr */
+	lea	__bss_stop,%a1
+	movel	%a1,_ramstart
+
+/*****************************************************************************
+ * If the kernel is in RAM, move romfs to right above bss and
+ * adjust _ramstart to where romfs ends.
+ *
+ * (Do this only if CONFIG_MTD_UCLINUX is true)
+ *****************************************************************************/
+
+#if defined(CONFIG_ROMFS_FS) && defined(CONFIG_RAMKERNEL) && \
+    defined(CONFIG_MTD_UCLINUX)
+	lea	__bss_start, %a0		/* get start of bss */
+	lea	__bss_stop, %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), -(%a1)			/* copy dword */
+	cmpl	%a0, %a2			/* check if at end */
+	bne	_copy_romfs
+#endif /* CONFIG_ROMFS_FS && CONFIG_RAMKERNEL && CONFIG_MTD_UCLINUX */
+
+/*****************************************************************************
+ * Clear bss region
+ *****************************************************************************/
+	lea	__bss_start, %a0		/* get start of bss */
+	lea	__bss_stop, %a1			/* get end of bss */
+_clear_bss:
+	movel	#0, (%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
+	jsr	start_kernel			/* start Linux kernel */
+_exit:
+	jmp	_exit				/* should never get here */