* Patch by Rick Bronson, 16 Mar 2003:

  Add support for Atmel AT91RM9200DK w/NAND

* Patches by Robert Schwebel, 19 Mar 2003:
  - use arm-linux-gcc as default compiler for ARM
  - fix i2c fixup code
  - fix missing baudrate setting
  - added $loadaddr / CFG_LOAD_ADDR support to loadb
  - moved "ignoring trailing characters" _before_ u-boot wants to
    print out diagnostics messages; removes bogus characters at the
    end of transmission

* Patch by John Zhan, 18 Mar 2003:
  Add support for SinoVee Microsystems SC8xx boards

* Patch by Rolf Offermanns, 21 Mar 2003:
  ported the dnp1110 related changes from the current armboot cvs to
  current u-boot cvs. smc91111 does not work. problem marked in
  smc91111.c, grep for "FIXME".

* Patch by Brian Auld, 25 Mar 2003:
  Add support for STM flash chips on ebony board

 * Add PCI support for MPC8250 Boards (PM825 module)

 * Patch by Stefan Roese, 25 Mar 2003:

6 files changed, 919 insertions, 0 deletions

diff --git a/cpu/at91rm9200/Makefile b/cpu/at91rm9200/Makefile
new file mode 100644
index 0000000000..0953c9f113
--- /dev/null
+++ b/cpu/at91rm9200/Makefile
@@ -0,0 +1,43 @@
+#
+# (C) Copyright 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	= serial.o interrupts.o cpu.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/at91rm9200/config.mk b/cpu/at91rm9200/config.mk
new file mode 100644
index 0000000000..deb7f87600
--- /dev/null
+++ b/cpu/at91rm9200/config.mk
@@ -0,0 +1,27 @@
+#
+# (C) Copyright 2002
+# Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+# Marius Groeger <mgroeger@sysgo.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 -mtune=arm7tdmi
diff --git a/cpu/at91rm9200/cpu.c b/cpu/at91rm9200/cpu.c
new file mode 100644
index 0000000000..f41210b545
--- /dev/null
+++ b/cpu/at91rm9200/cpu.c
@@ -0,0 +1,177 @@
+/*
+ * (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>
+ *
+ * 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 <AT91RM9200.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");
+    /*printf("p15/c1 is = %08lx\n", value); */
+    return value;
+}
+
+/* write to co-processor 15, register #1 (control register) */
+static void write_p15_c1(unsigned long value)
+{
+    /*printf("write %08lx to p15/c1\n", value); */
+    __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;
+
+    /* copro seems to need some delay between reading and writing */
+    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_IDC		(1<<2)	/* icache and/or dcache off/on */
+#define C1_WRITE_BUFFER	(1<<3)	/* write buffer off/on */
+#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_HIGH_VECTORS	(1<<13)	/* location of vectors: low/high addresses */
+
+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
+    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 ...
+     * and we set the CPU-speed to 73 MHz - see start.S for details
+     */
+
+    disable_interrupts();
+    return 0;
+}
+
+int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+
+#ifdef CFG_SOFT_RESET
+    extern void reset_cpu(ulong addr);
+
+    disable_interrupts();
+    reset_cpu(0);
+#else
+   AT91PS_USART us = AT91C_BASE_US1;
+   AT91PS_PIO pio = AT91C_BASE_PIOA;
+
+   /*shutdown the console to avoid strange chars during reset */
+   us->US_CR = (AT91C_US_RSTRX | AT91C_US_RSTTX);
+
+   /* Clear PA19 to trigger the hard reset */
+   pio->PIO_CODR = 0x00080000;
+   pio->PIO_OER  = 0x00080000;
+   pio->PIO_PER  = 0x00080000;
+   /* Never reached */
+#endif
+   return 0;
+}
+
+void icache_enable(void)
+{
+    ulong reg;
+    reg = read_p15_c1();
+    cp_delay();
+    write_p15_c1(reg | C1_IDC);
+}
+
+void icache_disable(void)
+{
+    ulong reg;
+    reg = read_p15_c1();
+    cp_delay();
+    write_p15_c1(reg & ~C1_IDC);
+}
+
+int icache_status(void)
+{
+    return (read_p15_c1() & C1_IDC) != 0;
+    return 0;
+}
+
+void dcache_enable(void)
+{
+    ulong reg;
+    reg = read_p15_c1();
+    cp_delay();
+    write_p15_c1(reg | C1_IDC);
+}
+
+void dcache_disable(void)
+{
+    ulong reg;
+    reg = read_p15_c1();
+    cp_delay();
+    write_p15_c1(reg & ~C1_IDC);
+}
+
+int dcache_status(void)
+{
+    return (read_p15_c1() & C1_IDC) != 0;
+    return 0;
+}
diff --git a/cpu/at91rm9200/interrupts.c b/cpu/at91rm9200/interrupts.c
new file mode 100644
index 0000000000..a14ef81d0c
--- /dev/null
+++ b/cpu/at91rm9200/interrupts.c
@@ -0,0 +1,236 @@
+/*
+ * (C) Copyright 2002
+ * Lineo, Inc. <www.lineo.com>
+ * Bernhard Kuhn <bkuhn@lineo.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>
+ *
+ * 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 <AT91RM9200.h>
+#include <asm/proc-armv/ptrace.h>
+
+extern void reset_cpu(ulong addr);
+
+/* we always count down the max. */
+#define TIMER_LOAD_VAL 0xffff
+
+/* macro to read the 16 bit timer */
+#define READ_TIMER (tmr->TC_CV)
+AT91PS_TC tmr;
+
+
+
+void enable_interrupts (void)
+{
+    return;
+}
+int disable_interrupts (void)
+{
+    return 0;
+}
+
+
+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 lastinc;
+
+int interrupt_init (void)
+{
+
+    tmr = AT91C_BASE_TC0;
+
+    /* enables TC1.0 clock */
+    *AT91C_PMC_PCER = 1 << AT91C_ID_TC0;  /* enable clock */
+
+    *AT91C_TCB0_BCR = 0;
+    *AT91C_TCB0_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_NONE | AT91C_TCB_TC2XC2S_NONE;
+    tmr->TC_CCR = AT91C_TC_CLKDIS;
+    tmr->TC_CMR = AT91C_TC_TIMER_DIV1_CLOCK;  /* set to MCLK/2 */
+
+    tmr->TC_IDR = ~0ul;
+    tmr->TC_RC = TIMER_LOAD_VAL;
+    lastinc = TIMER_LOAD_VAL;
+    tmr->TC_CCR = AT91C_TC_SWTRG | AT91C_TC_CLKEN;
+    timestamp = 0;
+    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;
+}
+
+void udelay(unsigned long usec)
+{
+    udelay_masked(usec);
+}
+
+void reset_timer_masked(void)
+{
+    /* reset time */
+    lastinc = READ_TIMER;
+    timestamp = 0;
+}
+
+ulong get_timer_masked(void)
+{
+    ulong now = READ_TIMER;
+    if (now >= lastinc)
+    {
+        /* normal mode */
+        timestamp += now - lastinc;
+    } else {
+        /* we have an overflow ... */
+        timestamp += now + TIMER_LOAD_VAL - lastinc;
+    }
+    lastinc = now;
+
+    return timestamp;
+}
+
+void udelay_masked(unsigned long usec)
+{
+    ulong tmo;
+
+    tmo = usec / 1000;
+    tmo *= CFG_HZ;
+    tmo /= 1000;
+
+    reset_timer_masked();
+
+    while(get_timer_masked() < tmo);
+      /*NOP*/;
+}
+
+
diff --git a/cpu/at91rm9200/serial.c b/cpu/at91rm9200/serial.c
new file mode 100644
index 0000000000..565cd3da8b
--- /dev/null
+++ b/cpu/at91rm9200/serial.c
@@ -0,0 +1,89 @@
+/*
+ * (C) Copyright 2002
+ * Lineo, Inc <www.lineo.com>
+ * Bernhard Kuhn <bkuhn@lineo.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>
+ *
+ * Copyright (C) 1999 2000 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl)
+ *
+ * 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 <AT91RM9200.h>
+
+/* ggi thunder */
+AT91PS_USART us = (AT91PS_USART) AT91C_BASE_DBGU;
+
+void serial_setbrg(void)
+  {
+  DECLARE_GLOBAL_DATA_PTR;
+  int baudrate;
+
+  if ((baudrate = gd->bd->bi_baudrate) <= 0)
+    baudrate = CONFIG_BAUDRATE;
+  us->US_BRGR = 33 /* AT91C_MASTER_CLOCK / baudrate / 16 */; /* hardcode so no __divsi3 */
+  }
+
+int serial_init(void)
+  {
+  /* make any port initializations specific to this port */
+  *AT91C_PIOA_PDR = AT91C_PA31_DTXD | AT91C_PA30_DRXD;  /* PA 31 & 30 */
+  *AT91C_PMC_PCER = 1 << AT91C_ID_SYS;  /* enable clock */
+  serial_setbrg();
+
+  us->US_CR = AT91C_US_RSTRX | AT91C_US_RSTTX;
+  us->US_CR = AT91C_US_RXEN | AT91C_US_TXEN;
+  us->US_MR = ( AT91C_US_CLKS_CLOCK | AT91C_US_CHRL_8_BITS | AT91C_US_PAR_NONE | AT91C_US_NBSTOP_1_BIT );
+  us->US_IMR = ~0ul;
+  return (0);
+  }
+
+void serial_putc(const char c)
+  {
+  if (c == '\n')
+    serial_putc('\r');
+  while( (us->US_CSR & AT91C_US_TXRDY) == 0 )
+    ;
+  us->US_THR=c;
+  }
+
+void
+serial_puts (const char *s)
+  {
+  while (*s)
+    {
+    serial_putc (*s++);
+    }
+  }
+
+int serial_getc(void)
+  {
+  while( (us->US_CSR & AT91C_US_RXRDY) == 0 );
+  return us->US_RHR;
+  }
+
+int serial_tstc(void)
+  {
+  return ((us->US_CSR & AT91C_US_RXRDY) == AT91C_US_RXRDY);
+  }
diff --git a/cpu/at91rm9200/start.S b/cpu/at91rm9200/start.S
new file mode 100644
index 0000000000..9b3e7aa0fd
--- /dev/null
+++ b/cpu/at91rm9200/start.S
@@ -0,0 +1,347 @@
+/*
+ *  armboot - Startup Code for ARM720 CPU-core
+ *
+ *  Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
+ *  Copyright (c) 2002	Alex Züpke <azu@sysgo.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 "config.h"
+#include "version.h"
+
+
+/*
+ *************************************************************************
+ *
+ * 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!
+ * relocate armboot to ram
+ * setup stack
+ * jump to second stage
+ *
+ *************************************************************************
+ */
+
+/*
+ * 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
+/*
+ * Note: armboot_end is defined by the (board-dependent) linker script
+ */
+.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,#0x13
+        msr     cpsr,r0
+
+	/*
+	 * relocate exeception table
+	 */
+	ldr	r0, =_start
+	ldr	r1, =0x0
+	mov	r2, #16
+copyex:
+	subs	r2, r2, #1
+	ldr	r3, [r0], #4
+	str	r3, [r1], #4
+	bne	copyex
+
+	/*
+         * we do sys-critical inits only at reboot,
+         * not when booting from ram!
+         */
+#ifdef CONFIG_INIT_CRITICAL
+        bl      cpu_init_crit
+#endif
+
+        /* 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
+ *
+ *************************************************************************
+ */
+
+cpu_init_crit:
+	# actually do nothing for now!
+	mov	pc, lr
+
+
+
+
+/*
+ *************************************************************************
+ *
+ * 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
+	stmia	sp, {r0 - r12}			@ Calling r0-r12
+	add     r8, sp, #S_PC
+
+	ldr	r2, _armboot_end
+	add	r2, r2, #CONFIG_STACKSIZE
+	sub	r2, r2, #8
+	ldmia	r2, {r2 - r4}                   @ get pc, cpsr, old_r0
+	add	r0, sp, #S_FRAME_SIZE		@ restore sp_SVC
+
+	add	r5, sp, #S_SP
+	mov	r1, lr
+	stmia	r5, {r0 - r4}                   @ save sp_SVC, lr_SVC, pc, cpsr, old_r
+	mov	r0, sp
+	.endm
+
+	.macro	irq_save_user_regs
+	sub	sp, sp, #S_FRAME_SIZE
+	stmia	sp, {r0 - r12}			@ Calling r0-r12
+	add     r8, sp, #S_PC
+	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		@ setup our mode stack
+	add	r13, r13, #CONFIG_STACKSIZE	@ resides at top of normal stack
+	sub	r13, r13, #8
+
+	str	lr, [r13]			@ save caller lr / spsr
+	mrs	lr, spsr
+	str     lr, [r13, #4]
+
+	mov	r13, #MODE_SVC			@ prepare SVC-Mode
+	msr	spsr_c, r13
+	mov	lr, pc
+	movs	pc, lr
+	.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:
+	mov     pc, r0