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#

# Copyright (c) 2006 Martin Decky

# All rights reserved.

#

# Redistribution and use in source and binary forms, with or without

# modification, are permitted provided that the following conditions

# are met:

#

# - Redistributions of source code must retain the above copyright

#   notice, this list of conditions and the following disclaimer.

# - 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.

# - The name of the author may not be used to endorse or promote products

#   derived from this software without specific prior written permission.

#

# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.

#

#include "asm.h"

#include "regname.h"

.text

.global halt

.global memcpy

.global jump_to_kernel

halt:

	b halt

memcpy:

	srwi. r7, r5, 3

	addi r6, r3, -4

	addi r4, r4, -4

	beq	2f

	andi. r0, r6, 3

	mtctr r7

	bne 5f

	1:

	lwz r7, 4(r4)

	lwzu r8, 8(r4)

	stw r7, 4(r6)

	stwu r8, 8(r6)

	bdnz 1b

	andi. r5, r5, 7

	2:

	cmplwi 0, r5, 4

	blt 3f

	lwzu r0, 4(r4)

	addi r5, r5, -4

	stwu r0, 4(r6)

	3:

	cmpwi 0, r5, 0

	beqlr

	mtctr r5

	addi r4, r4, 3

	addi r6, r6, 3

	4:

	lbzu r0, 1(r4)

	stbu r0, 1(r6)

	bdnz 4b

	blr

	5:

	subfic r0, r0, 4

	mtctr r0

	6:

	lbz r7, 4(r4)

	addi r4, r4, 1

	stb r7, 4(r6)

	addi r6, r6, 1

	bdnz 6b

	subf r5, r0, r5

	rlwinm. r7, r5, 32-3, 3, 31

	beq 2b

	mtctr r7

	b 1b

jump_to_kernel:

	# r3 = bootinfo (pa)

	# r4 = bootinfo_size

	# r5 = trans (pa)

	# r6 = bytes to copy

	# r7 = real_mode (pa)

	# r8 = framebuffer (pa)

	# r9 = scanline

	# disable interrupts

	mfmsr r31

	rlwinm r31, r31, 0, 17, 15

	mtmsr r31

	# set real_mode meeting point address

	mtspr srr0, r7

	# jumps to real_mode

	mfmsr r31

	lis r30, ~0@h

	ori r30, r30, ~(msr_ir | msr_dr)@l

	and r31, r31, r30

	mtspr srr1, r31

	sync

	isync

	rfid

.section REALMODE, "ax"

.align PAGE_WIDTH

.global real_mode

real_mode:

	# copy kernel to proper location

	#

	# r5 = trans (pa)

	# r6 = bytes to copy

	# r8 = framebuffer (pa)

	# r9 = scanline

	li r31, PAGE_SIZE >> 2

	li r30, 0

	page_copy:

		cmpwi r6, 0

		beq copy_end

		# copy page

		mtctr r31

		lwz r29, 0(r5)

		copy_loop:

			lwz r28, 0(r29)

			stw r28, 0(r30)

			addi r29, r29, 4

			addi r30, r30, 4

			subi r6, r6, 4

			cmpwi r6, 0

			beq copy_end

			bdnz copy_loop

		addi r5, r5, 4

		b page_copy

	copy_end:

	# initially fill segment registers

	li r31, 0

	li r29, 8

	mtctr r29

	li r30, 0                     # ASID 0 (VSIDs 0 .. 7)

	seg_fill_uspace:

		mtsrin r30, r31

		addi r30, r30, 1

		addis r31, r31, 0x1000    # move to next SR

		bdnz seg_fill_uspace

	li r29, 8

	mtctr r29

	lis r30, 0x4000               # priviledged access only

	ori r30, r30, 8               # ASID 0 (VSIDs 8 .. 15)

	seg_fill_kernel:

		mtsrin r30, r31

		addi r30, r30, 1

		addis r31, r31, 0x1000    # move to next SR

		bdnz seg_fill_kernel

	# create empty Page Hash Table

	# on top of memory, size 64 KB

	lwz r31, 0(r3)                # r31 = memory size

	lis r30, 65536@h

	ori r30, r30, 65536@l         # r30 = 65536

	subi r29, r30, 1              # r29 = 65535

	sub r31, r31, r30

	andc r31, r31, r29            # pht = ALIGN_DOWN(memory_size - 65536, 65536)

	mtsdr1 r31

	li r29, 2

	srw r30, r30, r29             # r30 = 16384

	li r29, 0

	pht_clear:

		# write zeroes

		stw r29, 0(r31)

		addi r31, r31, 4

		subi r30, r30, 4

		cmpwi r30, 0

		beq clear_end

		bdnz pht_clear

	clear_end:

	tlbsync

	# start the kernel

	#

	# pc = KERNEL_START_ADDR

	# r3 = bootinfo (pa)

	# sprg0 = KA2PA(KERNEL_START_ADDR)

	# sprg3 = physical memory size

	# sp = 0 (pa)

	lis r31, KERNEL_START_ADDR@ha

	addi r31, r31, KERNEL_START_ADDR@l

	mtspr srr0, r31

	subis r31, r31, 0x8000

	mtsprg0 r31

	lwz r31, 0(r3)

	mtsprg3 r31

	li sp, 0

	mfmsr r31

	ori r31, r31, (msr_ir | msr_dr)@l

	mtspr srr1, r31

	sync

	isync

	rfid

.align PAGE_WIDTH

.global trans

trans:

	.space (TRANS_SIZE * TRANS_ITEM_SIZE)