/* Boot entry point for MN10300 kernel
*
* Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/threads.h>
#include <linux/linkage.h>
#include <linux/serial_reg.h>
#include <asm/thread_info.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/frame.inc>
#include <asm/param.h>
#include <unit/serial.h>
.section .text.head,"ax"
###############################################################################
#
# bootloader entry point
#
###############################################################################
.globl _start
.type _start,@function
_start:
# save commandline pointer
mov d0,a3
# preload the PGD pointer register
mov swapper_pg_dir,d0
mov d0,(PTBR)
# turn on the TLBs
mov MMUCTR_IIV|MMUCTR_DIV,d0
mov d0,(MMUCTR)
mov MMUCTR_ITE|MMUCTR_DTE|MMUCTR_CE,d0
mov d0,(MMUCTR)
# turn on AM33v2 exception handling mode and set the trap table base
movhu (CPUP),d0
or CPUP_EXM_AM33V2,d0
movhu d0,(CPUP)
mov CONFIG_INTERRUPT_VECTOR_BASE,d0
mov d0,(TBR)
# invalidate and enable both of the caches
mov CHCTR,a0
clr d0
movhu d0,(a0) # turn off first
mov CHCTR_ICINV|CHCTR_DCINV,d0
movhu d0,(a0)
setlb
mov (a0),d0
btst CHCTR_ICBUSY|CHCTR_DCBUSY,d0 # wait till not busy
lne
#ifndef CONFIG_MN10300_CACHE_DISABLED
#ifdef CONFIG_MN10300_CACHE_WBACK
#ifndef CONFIG_MN10300_CACHE_WBACK_NOWRALLOC
mov CHCTR_ICEN|CHCTR_DCEN|CHCTR_DCWTMD_WRBACK,d0
#else
mov CHCTR_ICEN|CHCTR_DCEN|CHCTR_DCWTMD_WRBACK|CHCTR_DCALMD,d0
#endif /* CACHE_DISABLED */
#else
mov CHCTR_ICEN|CHCTR_DCEN|CHCTR_DCWTMD_WRTHROUGH,d0
#endif /* WBACK */
movhu d0,(a0) # enable
#endif /* NOWRALLOC */
# turn on RTS on the debug serial port if applicable
#ifdef CONFIG_MN10300_UNIT_ASB2305
bset UART_MCR_RTS,(ASB2305_DEBUG_MCR)
#endif
# clear the BSS area
mov __bss_start,a0
mov __bss_stop,a1
clr d0
bssclear:
cmp a1,a0
bge bssclear_end
mov d0,(a0)
inc4 a0
bra bssclear
bssclear_end:
# retrieve the parameters (including command line) before we overwrite
# them
cmp 0xabadcafe,d1
bne __no_parameters
__copy_parameters:
mov redboot_command_line,a0
mov a0,a1
add COMMAND_LINE_SIZE,a1
1:
movbu (a3),d0
inc a3
movbu d0,(a0)
inc a0
cmp a1,a0
blt 1b
mov redboot_platform_name,a0
mov a0,a1
add COMMAND_LINE_SIZE,a1
mov d2,a3
1:
movbu (a3),d0
inc a3
movbu d0,(a0)
inc a0
cmp a1,a0
blt 1b
__no_parameters:
# set up the registers with recognisable rubbish in them
mov init_thread_union+THREAD_SIZE-12,sp
mov 0xea01eaea,d0
mov d0,(4,sp) # EPSW save area
mov 0xea02eaea,d0
mov d0,(8,sp) # PC save area
mov 0xeb0060ed,d0
mov d0,mdr
mov 0xeb0061ed,d0
mov d0,mdrq
mov 0xeb0062ed,d0
mov d0,mcrh
mov 0xeb0063ed,d0
mov d0,mcrl
mov 0xeb0064ed,d0
mov d0,mcvf
mov 0xed0065ed,a3
mov a3,usp
mov 0xed00e0ed,e0
mov 0xed00e1ed,e1
mov 0xed00e2ed,e2
mov 0xed00e3ed,e3
mov 0xed00e4ed,e4
mov 0xed00e5ed,e5
mov 0xed00e6ed,e6
mov 0xed00e7ed,e7
mov 0xed00d0ed,d0
mov 0xed00d1ed,d1
mov 0xed00d2ed,d2
mov 0xed00d3ed,d3
mov 0xed00a0ed,a0
mov 0xed00a1ed,a1
mov 0xed00a2ed,a2
mov 0,a3
# set up the initial kernel stack
SAVE_ALL
mov 0xffffffff,d0
mov d0,(REG_ORIG_D0,fp)
# put different recognisable rubbish in the regs
mov 0xfb0060ed,d0
mov d0,mdr
mov 0xfb0061ed,d0
mov d0,mdrq
mov 0xfb0062ed,d0
mov d0,mcrh
mov 0xfb0063ed,d0
mov d0,mcrl
mov 0xfb0064ed,d0
mov d0,mcvf
mov 0xfd0065ed,a0
mov a0,usp
mov 0xfd00e0ed,e0
mov 0xfd00e1ed,e1
mov 0xfd00e2ed,e2
mov 0xfd00e3ed,e3
mov 0xfd00e4ed,e4
mov 0xfd00e5ed,e5
mov 0xfd00e6ed,e6
mov 0xfd00e7ed,e7
mov 0xfd00d0ed,d0
mov 0xfd00d1ed,d1
mov 0xfd00d2ed,d2
mov 0xfd00d3ed,d3
mov 0xfd00a0ed,a0
mov 0xfd00a1ed,a1
mov 0xfd00a2ed,a2
# we may be holding current in E2
#ifdef CONFIG_MN10300_CURRENT_IN_E2
mov init_task,e2
#endif
# initialise the processor and the unit
call processor_init[],0
call unit_init[],0
#ifdef CONFIG_GDBSTUB
call gdbstub_init[],0
#ifdef CONFIG_GDBSTUB_IMMEDIATE
.globl __gdbstub_pause
__gdbstub_pause:
bra __gdbstub_pause
#endif
#endif
jmp start_kernel
.size _start, _start-.
ENTRY(__head_end)
/*
* This is initialized to disallow all access to the low 2G region
* - the high 2G region is managed directly by the MMU
* - range 0x70000000-0x7C000000 are initialised for use by VMALLOC
*/
.section .bss
.balign PAGE_SIZE
ENTRY(swapper_pg_dir)
.space PTRS_PER_PGD*4
/*
* The page tables are initialized to only 8MB here - the final page
* tables are set up later depending on memory size.
*/
.balign PAGE_SIZE
ENTRY(empty_zero_page)
.space PAGE_SIZE
.balign PAGE_SIZE
ENTRY(empty_bad_page)
.space PAGE_SIZE
.balign PAGE_SIZE
ENTRY(empty_bad_pte_table)
.space PAGE_SIZE
.balign PAGE_SIZE
ENTRY(large_page_table)
.space PAGE_SIZE
.balign PAGE_SIZE
ENTRY(kernel_vmalloc_ptes)
.space ((VMALLOC_END-VMALLOC_START)/PAGE_SIZE)*4
