Patches by Kshitij, 04 Jul 2003

- added support for arm925t cpu core
- added support for TI OMAP 1510 Innovator Board

6 files changed, 1027 insertions, 0 deletions

diff --git a/cpu/arm925t/Makefile b/cpu/arm925t/Makefile
new file mode 100644
index 00000000000..a1db818a8ff
--- /dev/null
+++ b/cpu/arm925t/Makefile
@@ -0,0 +1,43 @@
+#
+# (C) Copyright 2000-2003
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+include $(TOPDIR)/config.mk
+
+LIB	= lib$(CPU).a
+
+START	= start.o
+OBJS	= interrupts.o cpu.o omap925.o
+
+all:	.depend $(START) $(LIB)
+
+$(LIB):	$(OBJS)
+	$(AR) crv $@ $(OBJS)
+
+#########################################################################
+
+.depend:	Makefile $(START:.o=.S) $(OBJS:.o=.c)
+		$(CC) -M $(CFLAGS) $(START:.o=.S) $(OBJS:.o=.c) > $@
+
+sinclude .depend
+
+#########################################################################
diff --git a/cpu/arm925t/config.mk b/cpu/arm925t/config.mk
new file mode 100644
index 00000000000..cef7d26f1cb
--- /dev/null
+++ b/cpu/arm925t/config.mk
@@ -0,0 +1,27 @@
+#
+# (C) Copyright 2002
+# Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+PLATFORM_RELFLAGS += -fno-strict-aliasing  -fno-common -ffixed-r8 \
+	-mshort-load-bytes -msoft-float
+
+PLATFORM_CPPFLAGS += -mapcs-32 -march=armv4
diff --git a/cpu/arm925t/cpu.c b/cpu/arm925t/cpu.c
new file mode 100644
index 00000000000..c55fbc7959f
--- /dev/null
+++ b/cpu/arm925t/cpu.c
@@ -0,0 +1,159 @@
+/*
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * CPU specific code
+ */
+
+#include <common.h>
+#include <command.h>
+#include <arm925t.h>
+
+/* read co-processor 15, register #1 (control register) */
+static unsigned long read_p15_c1 (void)
+{
+	unsigned long value;
+
+	__asm__ __volatile__(
+		"mrc	p15, 0, %0, c1, c0, 0   @ read control reg\n"
+		: "=r" (value)
+		:
+		: "memory");
+
+#ifdef MMU_DEBUG
+	printf ("p15/c1 is = %08lx\n", value);
+#endif
+	return value;
+}
+
+/* write to co-processor 15, register #1 (control register) */
+static void write_p15_c1 (unsigned long value)
+{
+#ifdef MMU_DEBUG
+	printf ("write %08lx to p15/c1\n", value);
+#endif
+	__asm__ __volatile__(
+		"mcr	p15, 0, %0, c1, c0, 0   @ write it back\n"
+		:
+		: "r" (value)
+		: "memory");
+
+	read_p15_c1 ();
+}
+
+static void cp_delay (void)
+{
+	volatile int i;
+
+	/* Many OMAP regs need at least 2 nops  */
+	for (i = 0; i < 100; i++);
+}
+
+/* See also ARM Ref. Man. */
+#define C1_MMU		(1<<0)		/* mmu off/on */
+#define C1_ALIGN	(1<<1)		/* alignment faults off/on */
+#define C1_DC		(1<<2)		/* dcache off/on */
+#define C1_WB		(1<<3)		/* merging write buffer on/off */
+#define C1_BIG_ENDIAN	(1<<7)	/* big endian off/on */
+#define C1_SYS_PROT	(1<<8)		/* system protection */
+#define C1_ROM_PROT	(1<<9)		/* ROM protection */
+#define C1_IC		(1<<12)		/* icache off/on */
+#define C1_HIGH_VECTORS	(1<<13)	/* location of vectors: low/high addresses */
+#define RESERVED_1	(0xf << 3)	/* must be 111b for R/W */
+
+int cpu_init (void)
+{
+	/*
+	 * setup up stack if necessary
+	 */
+#ifdef CONFIG_USE_IRQ
+	IRQ_STACK_START = _armboot_end +
+			CONFIG_STACKSIZE + CONFIG_STACKSIZE_IRQ - 4;
+	FIQ_STACK_START = IRQ_STACK_START + CONFIG_STACKSIZE_FIQ;
+	_armboot_real_end = FIQ_STACK_START + 4;
+#else
+	_armboot_real_end = _armboot_end + CONFIG_STACKSIZE;
+#endif	/* CONFIG_USE_IRQ */
+	return (0);
+}
+
+int cleanup_before_linux (void)
+{
+	/*
+	 * this function is called just before we call linux
+	 * it prepares the processor for linux
+	 *
+	 * we turn off caches etc ...
+	 */
+
+	unsigned long i;
+
+	disable_interrupts ();
+
+	/* turn off I/D-cache */
+	asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));
+	i &= ~(C1_DC | C1_IC);
+	asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
+
+	/* flush I/D-cache */
+	i = 0;
+	asm ("mcr p15, 0, %0, c7, c7, 0": :"r" (i));
+	return (0);
+}
+
+int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+	extern void reset_cpu (ulong addr);
+
+	disable_interrupts ();
+	reset_cpu (0);
+	/*NOTREACHED*/
+	return (0);
+}
+
+void icache_enable (void)
+{
+	ulong reg;
+
+	reg = read_p15_c1 ();		/* get control reg. */
+	cp_delay ();
+	write_p15_c1 (reg | C1_IC);
+}
+
+void icache_disable (void)
+{
+	ulong reg;
+
+	reg = read_p15_c1 ();
+	cp_delay ();
+	write_p15_c1 (reg & ~C1_IC);
+}
+
+int icache_status (void)
+{
+	return (read_p15_c1 () & C1_IC) != 0;
+}
diff --git a/cpu/arm925t/interrupts.c b/cpu/arm925t/interrupts.c
new file mode 100644
index 00000000000..ed8a1c7718a
--- /dev/null
+++ b/cpu/arm925t/interrupts.c
@@ -0,0 +1,301 @@
+/*
+ * (C) Copyright 2003
+ * Texas Instruments, <www.ti.com>
+ *
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Alex Zuepke <azu@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <arm925t.h>
+#include <configs/omap1510.h>
+
+#include <asm/proc-armv/ptrace.h>
+
+extern void reset_cpu(ulong addr);
+#define TIMER_LOAD_VAL 0xffffffff
+
+/* macro to read the 32 bit timer */
+#define READ_TIMER (*(volatile ulong *)(CFG_TIMERBASE+8))
+
+#ifdef CONFIG_USE_IRQ
+/* enable IRQ interrupts */
+void enable_interrupts (void)
+{
+	unsigned long temp;
+	__asm__ __volatile__("mrs %0, cpsr\n"
+			     "bic %0, %0, #0x80\n"
+			     "msr cpsr_c, %0"
+			     : "=r" (temp)
+			     :
+			     : "memory");
+}
+
+
+/*
+ * disable IRQ/FIQ interrupts
+ * returns true if interrupts had been enabled before we disabled them
+ */
+int disable_interrupts (void)
+{
+	unsigned long old,temp;
+	__asm__ __volatile__("mrs %0, cpsr\n"
+			     "orr %1, %0, #0xc0\n"
+			     "msr cpsr_c, %1"
+			     : "=r" (old), "=r" (temp)
+			     :
+			     : "memory");
+	return (old & 0x80) == 0;
+}
+#else
+void enable_interrupts (void)
+{
+	return;
+}
+int disable_interrupts (void)
+{
+	return 0;
+}
+#endif
+
+
+
+void bad_mode (void)
+{
+	panic ("Resetting CPU ...\n");
+	reset_cpu (0);
+}
+
+void show_regs (struct pt_regs *regs)
+{
+	unsigned long flags;
+	const char *processor_modes[] = {
+	"USER_26",	"FIQ_26",	"IRQ_26",	"SVC_26",
+	"UK4_26",	"UK5_26",	"UK6_26",	"UK7_26",
+	"UK8_26",	"UK9_26",	"UK10_26",	"UK11_26",
+	"UK12_26",	"UK13_26",	"UK14_26",	"UK15_26",
+	"USER_32",	"FIQ_32",	"IRQ_32",	"SVC_32",
+	"UK4_32",	"UK5_32",	"UK6_32",	"ABT_32",
+	"UK8_32",	"UK9_32",	"UK10_32",	"UND_32",
+	"UK12_32",	"UK13_32",	"UK14_32",	"SYS_32",
+	};
+
+	flags = condition_codes (regs);
+
+	printf ("pc : [<%08lx>]    lr : [<%08lx>]\n"
+		"sp : %08lx  ip : %08lx  fp : %08lx\n",
+		instruction_pointer (regs),
+		regs->ARM_lr, regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
+	printf ("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
+		regs->ARM_r10, regs->ARM_r9, regs->ARM_r8);
+	printf ("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
+		regs->ARM_r7, regs->ARM_r6, regs->ARM_r5, regs->ARM_r4);
+	printf ("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
+		regs->ARM_r3, regs->ARM_r2, regs->ARM_r1, regs->ARM_r0);
+	printf ("Flags: %c%c%c%c",
+		flags & CC_N_BIT ? 'N' : 'n',
+		flags & CC_Z_BIT ? 'Z' : 'z',
+		flags & CC_C_BIT ? 'C' : 'c', flags & CC_V_BIT ? 'V' : 'v');
+	printf ("  IRQs %s  FIQs %s  Mode %s%s\n",
+		interrupts_enabled (regs) ? "on" : "off",
+		fast_interrupts_enabled (regs) ? "on" : "off",
+		processor_modes[processor_mode (regs)],
+		thumb_mode (regs) ? " (T)" : "");
+}
+
+void do_undefined_instruction (struct pt_regs *pt_regs)
+{
+	printf ("undefined instruction\n");
+	show_regs (pt_regs);
+	bad_mode ();
+}
+
+void do_software_interrupt (struct pt_regs *pt_regs)
+{
+	printf ("software interrupt\n");
+	show_regs (pt_regs);
+	bad_mode ();
+}
+
+void do_prefetch_abort (struct pt_regs *pt_regs)
+{
+	printf ("prefetch abort\n");
+	show_regs (pt_regs);
+	bad_mode ();
+}
+
+void do_data_abort (struct pt_regs *pt_regs)
+{
+	printf ("data abort\n");
+	show_regs (pt_regs);
+	bad_mode ();
+}
+
+void do_not_used (struct pt_regs *pt_regs)
+{
+	printf ("not used\n");
+	show_regs (pt_regs);
+	bad_mode ();
+}
+
+void do_fiq (struct pt_regs *pt_regs)
+{
+	printf ("fast interrupt request\n");
+	show_regs (pt_regs);
+	bad_mode ();
+}
+
+void do_irq (struct pt_regs *pt_regs)
+{
+	printf ("interrupt request\n");
+	show_regs (pt_regs);
+	bad_mode ();
+}
+
+static ulong timestamp;
+static ulong lastdec;
+
+/* nothing really to do with interrupts, just starts up a counter. */
+int interrupt_init (void)
+{
+	int32_t val;
+
+	*((int32_t *) (CFG_TIMERBASE + LOAD_TIM)) = TIMER_LOAD_VAL;
+	val = MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE | (CFG_PVT << MPUTIM_PTV_BIT);
+	*((int32_t *) (CFG_TIMERBASE + CNTL_TIMER)) = val;
+	return (0);
+}
+
+/*
+ * timer without interrupts
+ */
+
+void reset_timer (void)
+{
+	reset_timer_masked ();
+}
+
+ulong get_timer (ulong base)
+{
+	return get_timer_masked () - base;
+}
+
+void set_timer (ulong t)
+{
+	timestamp = t;
+}
+
+/* very rough timer... */
+void udelay (unsigned long usec)
+{
+#ifdef CONFIG_INNOVATOROMAP1510
+#define LOOPS_PER_MSEC 60		/* tuned on omap1510 */
+	volatile int i, time_remaining = LOOPS_PER_MSEC * usec;
+
+	for (i = time_remaining; i > 0; i--) {
+	}
+#else
+
+	ulong tmo;
+
+	tmo = usec / 1000;
+	tmo *= CFG_HZ;
+	tmo /= 1000;
+
+	tmo += get_timer (0);
+
+	while (get_timer_masked () < tmo)
+		/*NOP*/;
+#endif
+}
+
+void reset_timer_masked (void)
+{
+	/* reset time */
+	lastdec = READ_TIMER;
+	timestamp = 0;
+}
+
+ulong get_timer_masked (void)
+{
+	ulong now = READ_TIMER;           /* current tick value */
+
+	if (lastdec >= now) {             /* did I roll (rem decrementer) */
+		/* normal mode */
+		timestamp += lastdec - now;   /* record amount of time since last check */
+	} else {
+		/* we have an overflow ... */
+		timestamp += lastdec + TIMER_LOAD_VAL - now;
+	}
+	lastdec = now;
+
+	return timestamp;
+}
+
+void udelay_masked (unsigned long usec)
+{
+#ifdef CONFIG_INNOVATOROMAP1510
+	#define LOOPS_PER_MSEC 60 /* tuned on omap1510 */
+	volatile int i, time_remaining = LOOPS_PER_MSEC*usec;
+    for (i=time_remaining; i>0; i--) { }
+#else
+
+	ulong tmo;
+
+	tmo = usec / 1000;
+	tmo *= CFG_HZ;
+	tmo /= 1000;
+
+	reset_timer_masked ();
+
+	while (get_timer_masked () < tmo)
+		/*NOP*/;
+#endif
+}
+
+/*
+ * This function is derived from PowerPC code (read timebase as long long).
+ * On ARM it just returns the timer value.
+ */
+unsigned long long get_ticks(void)
+{
+	return get_timer(0);
+}
+
+/*
+ * This function is derived from PowerPC code (timebase clock frequency).
+ * On ARM it returns the number of timer ticks per second.
+ */
+ulong get_tbclk (void)
+{	/* poor timer, may need to improve especiall for bootp. */
+	ulong tbclk;
+
+	tbclk = CFG_HZ;
+	return tbclk;
+}
diff --git a/cpu/arm925t/omap925.c b/cpu/arm925t/omap925.c
new file mode 100644
index 00000000000..1166ca695f6
--- /dev/null
+++ b/cpu/arm925t/omap925.c
@@ -0,0 +1,73 @@
+/*
+ * (C) Copyright 2003
+ * Texas Instruments <www.ti.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <command.h>
+#include <arm925t.h>
+
+ushort gpioreserved;
+
+void gpioreserve(ushort mask)
+{
+	gpioreserved |= mask;
+}
+
+void gpiosetdir(ushort mask, ushort in)
+{
+	*(ushort *)GPIO_DIR_CONTROL_REG = (*(ushort *)GPIO_DIR_CONTROL_REG & ~mask) | (in & mask);
+}
+
+
+void gpiosetout(ushort mask, ushort out)
+{
+	ushort *r_ptr, r_val;
+	
+	r_ptr = (ushort *)GPIO_DATA_OUTPUT_REG;	/* set pointer */
+	r_val = *r_ptr & ~mask;		/* get previous val, clear bits we want to change */
+	r_val |= (out & mask);		/* set specified bits in value + plus origional ones */
+	*r_ptr = r_val;			/* write it out */	
+/* 
+ * gcc screwed this one up :(.
+ * 
+ * *(ushort *)GPIO_DATA_OUTPUT_REG = (*(ushort *)GPIO_DATA_OUTPUT_REG & ~mask) | (out & mask);
+ */
+
+}
+
+void gpioinit(void)
+{
+}
+
+
+#define MIF_CONFIG_REG 0xFFFECC0C
+#define FLASH_GLOBAL_CTRL_NWP 1
+
+void archflashwp (void *archdata, int wp)
+{
+	ulong *fgc = (ulong *) MIF_CONFIG_REG;
+
+	if (wp == 1)
+		*fgc &= ~FLASH_GLOBAL_CTRL_NWP;
+	else
+		*fgc |= FLASH_GLOBAL_CTRL_NWP;
+}
diff --git a/cpu/arm925t/start.S b/cpu/arm925t/start.S
new file mode 100644
index 00000000000..2115fb30e9a
--- /dev/null
+++ b/cpu/arm925t/start.S
@@ -0,0 +1,424 @@
+/*
+ *  armboot - Startup Code for ARM925 CPU-core
+ *
+ *  Copyright (c) 2003  Texas Instruments
+ *
+ *  ----- Adapted for OMAP1510 from ARM920 code ------
+ *
+ *  Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
+ *  Copyright (c) 2002	Alex Züpke <azu@sysgo.de>
+ *  Copyright (c) 2002	Gary Jennejohn <gj@denx.de>
+ *  Copyright (c) 2003	Richard Woodruff <r-woodruff2@ti.com>
+ *  Copyright (c) 2003	Kshitij 	 <kshitij@ti.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+
+
+#include <config.h>
+#include <version.h>
+
+#if defined(CONFIG_OMAP1510)
+#include <./configs/omap1510.h>
+#endif
+
+/*
+ *************************************************************************
+ *
+ * Jump vector table as in table 3.1 in [1]
+ *
+ *************************************************************************
+ */
+
+
+.globl _start
+_start:	b       reset
+	ldr	pc, _undefined_instruction
+	ldr	pc, _software_interrupt
+	ldr	pc, _prefetch_abort
+	ldr	pc, _data_abort
+	ldr	pc, _not_used
+	ldr	pc, _irq
+	ldr	pc, _fiq
+
+_undefined_instruction:	.word undefined_instruction
+_software_interrupt:	.word software_interrupt
+_prefetch_abort:	.word prefetch_abort
+_data_abort:		.word data_abort
+_not_used:		.word not_used
+_irq:			.word irq
+_fiq:			.word fiq
+
+	.balignl 16,0xdeadbeef
+
+
+/*
+ *************************************************************************
+ *
+ * Startup Code (reset vector)
+ *
+ * do important init only if we don't start from memory!
+ * setup Memory and board specific bits prior to relocation.
+ * relocate armboot to ram
+ * setup stack
+ *
+ *************************************************************************
+ */
+
+/*
+ * CFG_MEM_END is in the board dependent config-file (configs/config_BOARD.h)
+ */
+_TEXT_BASE:
+	.word	TEXT_BASE
+
+.globl _armboot_start
+_armboot_start:
+	.word _start
+
+/*
+ * Note: _armboot_end_data and _armboot_end are defined
+ * by the (board-dependent) linker script.
+ * _armboot_end_data is the first usable FLASH address after armboot
+ */
+.globl _armboot_end_data
+_armboot_end_data:
+	.word armboot_end_data
+.globl _armboot_end
+_armboot_end:
+	.word armboot_end
+
+/*
+ * _armboot_real_end is the first usable RAM address behind armboot
+ * and the various stacks
+ */
+.globl _armboot_real_end
+_armboot_real_end:
+	.word 0x0badc0de
+
+#ifdef CONFIG_USE_IRQ
+/* IRQ stack memory (calculated at run-time) */
+.globl IRQ_STACK_START
+IRQ_STACK_START:
+	.word	0x0badc0de
+
+/* IRQ stack memory (calculated at run-time) */
+.globl FIQ_STACK_START
+FIQ_STACK_START:
+	.word 0x0badc0de
+#endif
+
+
+/*
+ * the actual reset code
+ */
+
+reset:
+	/*
+	 * set the cpu to SVC32 mode
+	 */
+	mrs	r0,cpsr
+	bic	r0,r0,#0x1f
+	orr	r0,r0,#0xd3
+	msr	cpsr,r0
+	
+	/*
+	 * Set up 925T mode
+	 */
+	mov r1, #0x81               /* Set ARM925T configuration. */
+	mcr p15, 0, r1, c15, c1, 0  /* Write ARM925T configuration register. */
+
+	/* 
+	 * turn off the watchdog, unlock/diable sequence
+	 */
+	mov  r1, #0xF5
+	ldr  r0, =WDTIM_MODE
+	strh r1, [r0]
+	mov  r1, #0xA0
+	strh r1, [r0]
+
+	/*
+	 * mask all IRQs by setting all bits in the INTMR - default
+	 */
+	mov r1, #0xffffffff
+	ldr r0, =REG_IHL1_MIR
+	str r1, [r0]
+	ldr r0, =REG_IHL2_MIR
+	str r1, [r0]
+
+	/* 
+	 * wait for dpll to lock
+	 */       
+	ldr  r0, =CK_DPLL1
+	mov  r1, #0x10
+	strh r1, [r0]
+poll1:
+	ldrh r1, [r0]
+	ands r1, r1, #0x01
+	beq poll1
+	bl  cpu_init_crit
+
+relocate:
+	/*
+	 * relocate armboot to RAM
+	 */
+	adr	r0, _start		/* r0 <- current position of code */
+	ldr	r2, _armboot_start
+	ldr	r3, _armboot_end
+	sub	r2, r3, r2		/* r2 <- size of armboot */
+	ldr	r1, _TEXT_BASE		/* r1 <- destination address */
+	add	r2, r0, r2		/* r2 <- source end address */
+
+	/*
+	 * r0 = source address
+	 * r1 = target address
+	 * r2 = source end address
+	 */
+copy_loop:
+	ldmia	r0!, {r3-r10}
+	stmia	r1!, {r3-r10}
+	cmp	r0, r2
+	ble	copy_loop
+
+	/* set up the stack */
+	ldr	r0, _armboot_end
+	add	r0, r0, #CONFIG_STACKSIZE
+	sub	sp, r0, #12		/* leave 3 words for abort-stack */
+
+	ldr	pc, _start_armboot
+
+_start_armboot:	.word start_armboot
+
+
+/*
+ *************************************************************************
+ *
+ * CPU_init_critical registers
+ *
+ * setup important registers
+ * setup memory timing
+ *
+ *************************************************************************
+ */
+
+
+cpu_init_crit:
+	/*
+	 * flush v4 I/D caches
+	 */
+	mov	r0, #0
+	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
+	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
+
+	/*
+	 * disable MMU stuff and caches
+	 */
+	mrc	p15, 0, r0, c1, c0, 0
+	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
+	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
+	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
+	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
+	mcr	p15, 0, r0, c1, c0, 0
+
+	/*
+	 * Go setup Memory and board specific bits prior to relocation.
+	 */
+	mov	ip, lr          /* perserve link reg across call */
+	bl	platformsetup   /* go setup pll,mux,memory */
+	mov	lr, ip          /* restore link */
+	mov	pc, lr          /* back to my caller */
+/*
+ *************************************************************************
+ *
+ * Interrupt handling
+ *
+ *************************************************************************
+ */
+
+@
+@ IRQ stack frame.
+@
+#define S_FRAME_SIZE	72
+
+#define S_OLD_R0	68
+#define S_PSR		64
+#define S_PC		60
+#define S_LR		56
+#define S_SP		52
+
+#define S_IP		48
+#define S_FP		44
+#define S_R10		40
+#define S_R9		36
+#define S_R8		32
+#define S_R7		28
+#define S_R6		24
+#define S_R5		20
+#define S_R4		16
+#define S_R3		12
+#define S_R2		8
+#define S_R1		4
+#define S_R0		0
+
+#define MODE_SVC 0x13
+#define I_BIT	 0x80
+
+/*
+ * use bad_save_user_regs for abort/prefetch/undef/swi ...
+ * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
+ */
+
+	.macro	bad_save_user_regs
+	sub	sp, sp, #S_FRAME_SIZE           @ carve out a frame on current user stack
+	stmia	sp, {r0 - r12}			@ Save user registers (now in svc mode) r0-r12
+
+	ldr	r2, _armboot_end                @ find top of stack
+	add	r2, r2, #CONFIG_STACKSIZE       @ find base of normal stack
+	sub	r2, r2, #8                      @ set base 2 words into abort stack
+	ldmia	r2, {r2 - r3}                   @ get values for "aborted" pc and cpsr (into parm regs)
+	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
+
+	add	r5, sp, #S_SP
+	mov	r1, lr
+	stmia	r5, {r0 - r3}                   @ save sp_SVC, lr_SVC, pc, cpsr
+	mov	r0, sp                          @ save current stack into r0 (param register)
+	.endm
+
+	.macro	irq_save_user_regs
+	sub	sp, sp, #S_FRAME_SIZE
+	stmia	sp, {r0 - r12}			@ Calling r0-r12
+	add     r8, sp, #S_PC                   @ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
+	stmdb   r8, {sp, lr}^                   @ Calling SP, LR
+	str     lr, [r8, #0]                    @ Save calling PC
+	mrs     r6, spsr
+	str     r6, [r8, #4]                    @ Save CPSR
+	str     r0, [r8, #8]                    @ Save OLD_R0
+	mov	r0, sp
+	.endm
+
+	.macro	irq_restore_user_regs
+	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
+	mov	r0, r0
+	ldr	lr, [sp, #S_PC]			@ Get PC
+	add	sp, sp, #S_FRAME_SIZE
+	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
+	.endm
+
+	.macro get_bad_stack
+	ldr	r13, _armboot_end		@ get bottom of stack (into sp by by user stack pointer).
+	add	r13, r13, #CONFIG_STACKSIZE	@ head to reserved words at the top of the stack
+	sub	r13, r13, #8                    @ reserved a couple spots in abort stack
+
+	str	lr, [r13]			@ save caller lr in position 0 of saved stack
+	mrs	lr, spsr                        @ get the spsr
+	str     lr, [r13, #4]                   @ save spsr in position 1 of saved stack
+
+	mov	r13, #MODE_SVC			@ prepare SVC-Mode
+	@ msr	spsr_c, r13
+	msr	spsr, r13                       @ switch modes, make sure moves will execute
+	mov	lr, pc                          @ capture return pc
+	movs	pc, lr                          @ jump to next instruction & switch modes.
+	.endm
+
+	.macro get_irq_stack			@ setup IRQ stack
+	ldr	sp, IRQ_STACK_START
+	.endm
+
+	.macro get_fiq_stack			@ setup FIQ stack
+	ldr	sp, FIQ_STACK_START
+	.endm
+
+/*
+ * exception handlers
+ */
+	.align  5
+undefined_instruction:
+	get_bad_stack
+	bad_save_user_regs
+	bl 	do_undefined_instruction
+
+	.align	5
+software_interrupt:
+	get_bad_stack
+	bad_save_user_regs
+	bl 	do_software_interrupt
+
+	.align	5
+prefetch_abort:
+	get_bad_stack
+	bad_save_user_regs
+	bl 	do_prefetch_abort
+
+	.align	5
+data_abort:
+	get_bad_stack
+	bad_save_user_regs
+	bl 	do_data_abort
+
+	.align	5
+not_used:
+	get_bad_stack
+	bad_save_user_regs
+	bl 	do_not_used
+
+#ifdef CONFIG_USE_IRQ
+
+	.align	5
+irq:
+	get_irq_stack
+	irq_save_user_regs
+	bl 	do_irq
+	irq_restore_user_regs
+
+	.align	5
+fiq:
+	get_fiq_stack
+	/* someone ought to write a more effiction fiq_save_user_regs */
+	irq_save_user_regs
+	bl 	do_fiq
+	irq_restore_user_regs
+
+#else
+
+	.align	5
+irq:
+	get_bad_stack
+	bad_save_user_regs
+	bl 	do_irq
+
+	.align	5
+fiq:
+	get_bad_stack
+	bad_save_user_regs
+	bl 	do_fiq
+
+#endif
+
+	.align	5
+.globl reset_cpu
+reset_cpu:
+	ldr	r1, rstctl1     /* get clkm1 reset ctl */
+	mov     r3, #0x0        
+	strh	r3, [r1]        /* clear it */
+	mov     r3, #0x8
+	strh    r3, [r1]        /* force dsp+arm reset */
+_loop_forever:
+	b	_loop_forever
+rstctl1:
+	.word	0xfffece10