src/arch/i386/include/comboot.h

   1 #ifndef COMBOOT_H
   2 #define COMBOOT_H
   3
   4 /**
   5  * @file
   6  *
   7  * SYSLINUX COMBOOT
   8  */
   9
  10 FILE_LICENCE ( GPL2_OR_LATER );
  11
  12 #include <stdint.h>
  13 #include <setjmp.h>
  14 #include <gpxe/in.h>
  15
  16 /** Descriptor in a 32-bit IDT */
  17 struct idt_descriptor {
  18         uint16_t offset_low;
  19         uint16_t selector;
  20         uint16_t flags;
  21         uint16_t offset_high;
  22 } __attribute__ (( packed ));
  23
  24 /** Operand for the LIDT instruction */
  25 struct idt_register {
  26         uint16_t limit;
  27         uint32_t base;
  28 } __attribute__ (( packed ));
  29
  30 /** Entry in the interrupt jump buffer */
  31 struct ijb_entry {
  32         uint8_t pusha_instruction;
  33         uint8_t mov_instruction;
  34         uint8_t mov_value;
  35         uint8_t jump_instruction;
  36         uint32_t jump_destination;
  37 } __attribute__ (( packed ));
  38
  39 /** The x86 opcode for "pushal" */
  40 #define IJB_PUSHA 0x60
  41
  42 /** The x86 opcode for "movb $imm8,%al" */
  43 #define IJB_MOV_AL_IMM8 0xB0
  44
  45 /** The x86 opcode for "jmp rel32" */
  46 #define IJB_JMP_REL32 0xE9
  47
  48 /** Flags that specify a 32-bit interrupt gate with DPL=0 */
  49 #define IDT_INTERRUPT_GATE_FLAGS 0x8E00
  50
  51 /** Address of COM32 interrupt descriptor table */
  52 #define COM32_IDT 0x100000
  53
  54 /** Number of entries in a fully populated IDT */
  55 #define COM32_NUM_IDT_ENTRIES 256
  56
  57 /** Address of COM32 interrupt jump buffer */
  58 #define COM32_IJB 0x100800
  59
  60 /** Segment used for COMBOOT PSP and image */
  61 #define COMBOOT_PSP_SEG 0x07C0
  62
  63 /** Entry point address of COM32 images */
  64 #define COM32_START_PHYS 0x101000
  65
  66 /** COM32 bounce buffer segment */
  67 #define COM32_BOUNCE_SEG 0x07C0
  68
  69 /** Size of SYSLINUX file block in bytes */
  70 #define COMBOOT_FILE_BLOCKSZ 512
  71
  72 /** COMBOOT feature flags (INT 22h AX=15h) */
  73 #define COMBOOT_FEATURE_LOCAL_BOOT (1 << 0)
  74 #define COMBOOT_FEATURE_IDLE_LOOP  (1 << 1)
  75
  76 /** Maximum number of shuffle descriptors for
  77  * shuffle and boot functions
  78  * (INT 22h AX=0012h, 001Ah, 001Bh)
  79  */
  80 #define COMBOOT_MAX_SHUFFLE_DESCRIPTORS 682
  81
  82 typedef union {
  83         uint32_t l;
  84         uint16_t w[2];
  85         uint8_t  b[4];
  86 } com32_reg32_t;
  87
  88 typedef struct {
  89         uint16_t gs;                /* Offset  0 */
  90         uint16_t fs;                /* Offset  2 */
  91         uint16_t es;                /* Offset  4 */
  92         uint16_t ds;                /* Offset  6 */
  93
  94         com32_reg32_t edi;          /* Offset  8 */
  95         com32_reg32_t esi;          /* Offset 12 */
  96         com32_reg32_t ebp;          /* Offset 16 */
  97         com32_reg32_t _unused_esp;  /* Offset 20 */
  98         com32_reg32_t ebx;          /* Offset 24 */
  99         com32_reg32_t edx;          /* Offset 28 */
 100         com32_reg32_t ecx;          /* Offset 32 */
 101         com32_reg32_t eax;          /* Offset 36 */
 102
 103         com32_reg32_t eflags;       /* Offset 40 */
 104 } com32sys_t;
 105
 106 typedef struct {
 107         uint32_t eax;               /* Offset  0 */
 108         uint32_t ecx;               /* Offset  4 */
 109         uint32_t edx;               /* Offset  8 */
 110         uint32_t ebx;               /* Offset 12 */
 111         uint32_t esp;               /* Offset 16 */
 112         uint32_t ebp;               /* Offset 20 */
 113         uint32_t esi;               /* Offset 24 */
 114         uint32_t edi;               /* Offset 28 */
 115
 116         uint32_t eip;               /* Offset 32 */
 117 } syslinux_pm_regs;
 118
 119 typedef struct {
 120         uint16_t es;                /* Offset  0 */
 121         uint16_t _unused_cs;        /* Offset  2 */
 122         uint16_t ds;                /* Offset  4 */
 123         uint16_t ss;                /* Offset  6 */
 124         uint16_t fs;                /* Offset  8 */
 125         uint16_t gs;                /* Offset 10 */
 126
 127         uint32_t eax;                /* Offset 12 */
 128         uint32_t ecx;                /* Offset 16 */
 129         uint32_t edx;                /* Offset 20 */
 130         uint32_t ebx;                /* Offset 24 */
 131         uint32_t esp;                /* Offset 28 */
 132         uint32_t ebp;                /* Offset 32 */
 133         uint32_t esi;                /* Offset 36 */
 134         uint32_t edi;                /* Offset 40 */
 135
 136         uint16_t ip;                /* Offset 44 */
 137         uint16_t cs;                /* Offset 46 */
 138 } syslinux_rm_regs;
 139
 140 typedef struct {
 141         uint32_t dest;
 142         uint32_t src;
 143         uint32_t len;
 144 } comboot_shuffle_descriptor;
 145
 146 extern void hook_comboot_interrupts ( );
 147 extern void unhook_comboot_interrupts ( );
 148
 149 /* These are not the correct prototypes, but it doens't matter,
 150  * as we only ever get the address of these functions;
 151  * they are only called from COM32 code running in PHYS_CODE
 152  */
 153 extern void com32_intcall_wrapper ( );
 154 extern void com32_farcall_wrapper ( );
 155 extern void com32_cfarcall_wrapper ( );
 156 extern void com32_irq_wrapper ( );
 157
 158 /* Resolve a hostname to an (IPv4) address */
 159 extern int comboot_resolv ( const char *name, struct in_addr *address );
 160
 161 /* setjmp/longjmp context buffer used to return after loading an image */
 162 extern rmjmp_buf comboot_return;
 163
 164 /* Replacement image when exiting with COMBOOT_EXIT_RUN_KERNEL */
 165 extern struct image *comboot_replacement_image;
 166
 167 extern void *com32_external_esp;
 168
 169 #define COMBOOT_EXIT 1
 170 #define COMBOOT_EXIT_RUN_KERNEL 2
 171 #define COMBOOT_EXIT_COMMAND 3
 172
 173 extern void comboot_force_text_mode ( void );
 174
 175 #define COMBOOT_VIDEO_GRAPHICS    0x01
 176 #define COMBOOT_VIDEO_NONSTANDARD 0x02
 177 #define COMBOOT_VIDEO_VESA        0x04
 178 #define COMBOOT_VIDEO_NOTEXT      0x08
 179
 180 #endif