arch/h8300/kernel/head_ram.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #include <linux/sys.h>
   4 #include <linux/init.h>
   5 #include <asm/unistd.h>
   6 #include <asm/setup.h>
   7 #include <asm/segment.h>
   8 #include <asm/linkage.h>
   9 #include <asm/asm-offsets.h>
  10 #include <asm/thread_info.h>
  11 #include <asm/errno.h>
  12
  13 #if defined(CONFIG_CPU_H8300H)
  14         .h8300h
  15 #define SYSCR 0xfee012
  16 #define IRAMTOP 0xffff20
  17 #endif
  18 #if defined(CONFIG_CPU_H8S)
  19         .h8300s
  20 #define INTCR 0xffff31
  21 #define IRAMTOP 0xffc000
  22 #endif
  23
  24         __HEAD
  25         .global _start
  26 _start:
  27         mov.l   #IRAMTOP,sp
  28         /* .bss clear */
  29         mov.l   #_sbss,er5
  30         mov.l   #_ebss,er4
  31         sub.l   er5,er4
  32         shlr    er4
  33         shlr    er4
  34         sub.l   er2,er2
  35 1:
  36         mov.l   er2,@er5
  37         adds    #4,er5
  38         dec.l   #1,er4
  39         bne     1b
  40         jsr     @h8300_fdt_init
  41
  42         /* linux kernel start */
  43 #if defined(CONFIG_CPU_H8300H)
  44         ldc     #0xd0,ccr       /* running kernel */
  45         mov.l   #SYSCR,er0
  46         bclr    #3,@er0
  47 #endif
  48 #if defined(CONFIG_CPU_H8S)
  49         ldc     #0x07,exr
  50         bclr    #4,@INTCR:8
  51         bset    #5,@INTCR:8     /* Interrupt mode 2 */
  52         ldc     #0x90,ccr       /* running kernel */
  53 #endif
  54         mov.l   #init_thread_union,sp
  55         add.l   #0x2000,sp
  56         jsr     @start_kernel
  57
  58 1:
  59         bra     1b
  60
  61         .end