src/smm.c

   1 /*
   2  * smm.c
   3  * SMM support for BIOS.
   4  *
   5  * Copyright (C) 2002  MandrakeSoft S.A.
   6  * Copyright (C) 2008  Nguyen Anh Quynh <aquynh@gmail.com>
   7  *
   8  * This file may be distributed under the terms of the GNU GPLv3 license.
   9  */
  10
  11 #include "types.h"
  12 #include "pci.h"
  13 #include "smm.h" // smm_init
  14 #include "config.h" // CONFIG_*
  15 #include "util.h" // memcpy
  16
  17 #ifdef CONFIG_SMM
  18
  19 asm (
  20 "    .global smm_relocation_start                               \n"
  21 "    .global smm_relocation_end                                 \n"
  22 "    .global smm_code_start                                     \n"
  23 "    .global smm_code_end                                       \n"
  24 "                                                               \n"
  25 "    .code16                                                    \n"
  26 "    /* code to relocate SMBASE to 0xa0000 */                   \n"
  27 "smm_relocation_start:                                          \n"
  28 "    movl $0x38000 + 0x7efc, %ebx                               \n"
  29 "    /* revision ID to see if x86_64 or x86 */                  \n"
  30 "    mov (%ebx), %al                                            \n"
  31 "    cmpb $0x64, %al                                            \n"
  32 "    je 1f                                                      \n"
  33 "    movl $0x38000 + 0x7ef8, %ebx                               \n"
  34 "    jmp 2f                                                     \n"
  35 "1:                                                             \n"
  36 "    movl $0x38000 + 0x7f00, %ebx                               \n"
  37 "2:                                                             \n"
  38 "    movl $0xa0000, %eax                                        \n"
  39 "    movl %eax, (%ebx)                                          \n"
  40 "    /* indicate to the BIOS that the SMM code was executed */  \n"
  41 "    mov $0x00, %al                                             \n"
  42 "    movw $0xb3, %dx                                            \n"
  43 "    outb %al, %dx                                              \n"
  44 "    rsm                                                        \n"
  45 "smm_relocation_end:                                            \n"
  46 "                                                               \n"
  47 "    /* minimal SMM code to enable or disable ACPI */           \n"
  48 "smm_code_start:                                                \n"
  49 "    movw $0xb2, %dx                                            \n"
  50 "    inb %dx, %al                                               \n"
  51 "    cmp $0xf0, %al                                             \n"
  52 "    jne 1f                                                     \n"
  53 "                                                               \n"
  54 "    /* ACPI disable */                                         \n"
  55 "    //mov $PM_IO_BASE + 0x04, %dx /* PMCNTRL */                \n"
  56 "    mov $0xb000 + 0x04, %dx /* PMCNTRL */                      \n"
  57 "    inw %dx, %ax                                               \n"
  58 "    andw $~1, %ax                                              \n"
  59 "    outw %ax, %dx                                              \n"
  60 "                                                               \n"
  61 "    jmp 2f                                                     \n"
  62 "1:                                                             \n"
  63 "    cmp $0xf1, %al                                             \n"
  64 "    jne 2f                                                     \n"
  65 "                                                               \n"
  66 "    /* ACPI enable */                                          \n"
  67 "    //mov $PM_IO_BASE + 0x04, %dx /* PMCNTRL */                \n"
  68 "    mov $0xb000 + 0x04, %dx /* PMCNTRL */                      \n"
  69 "    inw %dx, %ax                                               \n"
  70 "    orw $1, %ax                                                \n"
  71 "    outw %ax, %dx                                              \n"
  72 "                                                               \n"
  73 "2:                                                             \n"
  74 "    rsm                                                        \n"
  75 "smm_code_end:                                                  \n"
  76 "    .code32                                                    \n"
  77     );
  78
  79 extern u8 smm_relocation_start, smm_relocation_end;
  80 extern u8 smm_code_start, smm_code_end;
  81
  82 void
  83 smm_init(PCIDevice *d)
  84 {
  85     u32 value;
  86
  87     /* check if SMM init is already done */
  88     value = pci_config_readl(d, 0x58);
  89     if ((value & (1 << 25)) == 0) {
  90         /* copy the SMM relocation code */
  91         memcpy((void *)0x38000, &smm_relocation_start,
  92                &smm_relocation_end - &smm_relocation_start);
  93
  94         /* enable SMI generation when writing to the APMC register */
  95         pci_config_writel(d, 0x58, value | (1 << 25));
  96
  97         /* init APM status port */
  98         outb(0x01, 0xb3);
  99
 100         /* raise an SMI interrupt */
 101         outb(0x00, 0xb2);
 102
 103         /* wait until SMM code executed */
 104         while (inb(0xb3) != 0x00);
 105
 106         /* enable the SMM memory window */
 107         pci_config_writeb(&i440_pcidev, 0x72, 0x02 | 0x48);
 108
 109         /* copy the SMM code */
 110         memcpy((void *)0xa8000, &smm_code_start,
 111                &smm_code_end - &smm_code_start);
 112         wbinvd();
 113
 114         /* close the SMM memory window and enable normal SMM */
 115         pci_config_writeb(&i440_pcidev, 0x72, 0x02 | 0x08);
 116     }
 117 }
 118 #endif