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      1 /////////////////////////////////////////////////////////////////////////
      2 // $Id$
      3 /////////////////////////////////////////////////////////////////////////
      4 //
      5 //  32 bit Bochs BIOS init code
      6 //  Copyright (C) 2006 Fabrice Bellard
      7 //
      8 //  This library is free software; you can redistribute it and/or
      9 //  modify it under the terms of the GNU Lesser General Public
     10 //  License as published by the Free Software Foundation; either
     11 //  version 2 of the License, or (at your option) any later version.
     12 //
     13 //  This library is distributed in the hope that it will be useful,
     14 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
     15 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     16 //  Lesser General Public License for more details.
     17 //
     18 //  You should have received a copy of the GNU Lesser General Public
     19 //  License along with this library; if not, write to the Free Software
     20 //  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
     21 #include "rombios.h"
     22 
     23 .globl _start
     24 .globl smp_ap_boot_code_start
     25 .globl smp_ap_boot_code_end
     26 .global smm_relocation_start
     27 .global smm_relocation_end
     28 .global smm_code_start
     29 .global smm_code_end
     30 
     31 _start:
     32   /* clear bss section */
     33   xor %eax, %eax
     34   mov $__bss_start, %edi
     35   mov $__bss_end, %ecx
     36   sub %edi, %ecx
     37   rep stosb
     38 
     39   /* copy data section */
     40   mov $_end, %esi
     41   mov $__data_start, %edi
     42   mov $__data_end, %ecx
     43   sub %edi, %ecx
     44   rep movsb
     45 
     46   jmp rombios32_init
     47 
     48   .code16
     49 smp_ap_boot_code_start:
     50   cli
     51   xor %ax, %ax
     52   mov %ax, %ds
     53 
     54   mov $SMP_MSR_ADDR, %ebx
     55 11:
     56   mov 0(%ebx), %ecx
     57   test %ecx, %ecx
     58   jz 12f
     59   mov 4(%ebx), %eax
     60   mov 8(%ebx), %edx
     61   wrmsr
     62   add $12, %ebx
     63   jmp 11b
     64 12:
     65 
     66   lock incw smp_cpus
     67 1:
     68   hlt
     69   jmp 1b
     70 smp_ap_boot_code_end:
     71 
     72 /* code to relocate SMBASE to 0xa0000 */
     73 smm_relocation_start:
     74   mov $0x38000 + 0x7efc, %ebx
     75   addr32 mov (%ebx), %al  /* revision ID to see if x86_64 or x86 */
     76   cmp $0x64, %al
     77   je 1f
     78   mov $0x38000 + 0x7ef8, %ebx
     79   jmp 2f
     80 1:
     81   mov $0x38000 + 0x7f00, %ebx
     82 2:
     83   movl $0xa0000, %eax
     84   addr32 movl %eax, (%ebx)
     85   /* indicate to the BIOS that the SMM code was executed */
     86   mov $0x00, %al
     87   movw $0xb3, %dx
     88   outb %al, %dx
     89   rsm
     90 smm_relocation_end:
     91 
     92 /* minimal SMM code to enable or disable ACPI */
     93 smm_code_start:
     94   movw $0xb2, %dx
     95   inb %dx, %al
     96   cmp $0xf0, %al
     97   jne 1f
     98 
     99   /* ACPI disable */
    100   mov $PM_IO_BASE + 0x04, %dx /* PMCNTRL */
    101   inw %dx, %ax
    102   andw $~1, %ax
    103   outw %ax, %dx
    104 
    105   jmp 2f
    106 
    107 1:
    108   cmp $0xf1, %al
    109   jne 2f
    110 
    111   /* ACPI enable */
    112   mov $PM_IO_BASE + 0x04, %dx /* PMCNTRL */
    113   inw %dx, %ax
    114   orw $1, %ax
    115   outw %ax, %dx
    116 
    117 2:
    118   rsm
    119 smm_code_end:
    120