/*-
 * Copyright (c) 2005, Kohsuke Ohtani
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * head.S - low level platform support
 *
 * This file contains the code from crt0.S which is released under
 * public domain by Jeff Frohwein.
 */

/*
 * I know that I'm a bit slacky, but this is the memory map for cats.
 * GXemul> device list
 * 0:                       ram @ 0x00041000000, len = 0x40000 (DYNTRANS R+W)
 * 1:                footbridge @ 0x00042000000, len = 0x400
 * 2:                       ram @ 0x00050000000, len = 0x10000 (DYNTRANS R+W)
 * 3:            footbridge_isa @ 0x00079000000, len = 0x8
 * 4:            footbridge_pci @ 0x0007b000000, len = 0x1000000
 * 5:                      8259 @ 0x0007c000020, len = 0x2
 * 6:                      8253 @ 0x0007c000040, len = 0x4
 * 7:                     pckbc @ 0x0007c000060, len = 0x10
 * 8:                    pccmos @ 0x0007c000070, len = 0x4
 * 9:          8259 [secondary] @ 0x0007c0000a0, len = 0x2
 * 10:            ns16550 [tty1] @ 0x0007c0002f8, len = 0x8
 * 11:                 lpt [lpt] @ 0x0007c000378, len = 0x3
 * 12:                  vga_ctrl @ 0x0007c0003c0, len = 0x20
 * 13:            ns16550 [tty0] @ 0x0007c0003f8, len = 0x8
 * 14: dec21143 [10:20:30:00:00:10] @ 0x0007c010000, len = 0x100
 * 15:                       ram @ 0x00080000000, len = 0x1000 (DYNTRANS R+W)
 * 16:              ram [mirror] @ 0x00080010000, len = 0x100 ()
 * 17:                   vga_gfx @ 0x000800a0000, len = 0x18000 ()
 * 18:             vga_charcells @ 0x000800b8000, len = 0x8000 (DYNTRANS R+W)
 * 19:              ram [mirror] @ 0x000c0000000, len = 0x20000000 (DYNTRANS R+W)
 * 20:              ram [mirror] @ 0x000f0000000, len = 0x1000000 (DYNTRANS R+W)
 * 21:                  fb [VGA] @ 0x01c00000000, len = 0xbb800 (DYNTRANS R+W)
 * 22:                  mc146818 @ 0x01d00000000, len = 0x2
 *
 * Firmware loads us at 0xf0000000 with MMU on and TTB @0x006f8000.
 */

#include <conf/config.h>
#include <platform.h>

#define ENTRY(x) .global x; .align; x##:

	.section ".text","ax"
	.code 32
/*
 * Kernel start point
 */
ENTRY(boot_entry)
	b	start_vector

stack_end:	.word	BOOT_STACK+0xf00
ENTRY(ebsabootaddr)
	.word	0

start_vector:
	mov	r1, #0xd3		/* Enter SVC mode, Disable IRQ,FIQ */
	msr	cpsr_c, r1

	mrc p15, 0, r1, c1, c0
	bic r1, r1, #1	/* disable MMU */
	mcr p15, 0, r1, c1, c0

	/* setup bootldr stack */
	ldr	sp, stack_end

	/* grab firmware bootinfo */
	ldr	r1, =ebsabootaddr
	str r0, [r1]

	/* initialize boot console */
	bl	bootcons_init

	ldr	r0, =loader_main
	bx	r0		/* Change to ARM mode */

/*
 * Start kernel
 */
ENTRY(start_kernel)
	/*
	 * XXX Copy kernel vectors and their displacement constants
	 * XXX to the beginning of physical memory.
	 * NOTE: it shouldn't hurt if we replace first 15 words of ourselfes.
	 */
	mov r2, #0	/* counter */
	mov r3, #15	/* num. of current insn */
	mov r4, #0	/* save addr */
	mov r5, r0	/* load addr */
	mov r6, #0	/* data */

copy_insn:	
	ldr r6, [r5], #4	/* load insn */
	str r6, [r4], #4	/* save insn */
	add r2, r2, #1		/* increment counter */
	tst r2, r3
	bne copy_insn

	bx	r0

		.section .tail,"ax"
dummy:
	.byte	0xff

.end