diff options
Diffstat (limited to 'arch/mn10300/kernel/head.S')
| -rw-r--r-- | arch/mn10300/kernel/head.S | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/arch/mn10300/kernel/head.S b/arch/mn10300/kernel/head.S new file mode 100644 index 00000000000..606bd8c6758 --- /dev/null +++ b/arch/mn10300/kernel/head.S @@ -0,0 +1,255 @@ +/* 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 <asm/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 |