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 000000000000..606bd8c6758d
--- /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