| 1 | /* Real-mode interface
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| 2 | */
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| 3 |
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| 4 | #ifndef ASSEMBLY
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| 5 |
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| 6 | #include "etherboot.h"
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| 7 | #include "segoff.h"
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| 8 |
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| 9 | typedef union {
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| 10 | struct {
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| 11 | union {
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| 12 | uint8_t l;
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| 13 | uint8_t byte;
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| 14 | };
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| 15 | uint8_t h;
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| 16 | } PACKED;
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| 17 | uint16_t word;
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| 18 | } PACKED reg16_t;
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| 19 |
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| 20 | typedef union {
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| 21 | reg16_t w;
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| 22 | uint32_t dword;
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| 23 | } PACKED reg32_t;
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| 24 |
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| 25 | /* Macros to help with defining inline real-mode trampoline fragments.
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| 26 | */
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| 27 | #ifdef VBOX
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| 28 | #ifdef __WIN32__
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| 29 | /* Switching to previous section is only supported with ELF format. */
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| 30 | #define RM_SWITCH_PREV_SEGMENT ".section .text"
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| 31 | #else /* __WIN32__ */
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| 32 | #define RM_SWITCH_PREV_SEGMENT ".previous"
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| 33 | #endif /* __WIN32__ */
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| 34 | #else /* !VBOX */
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| 35 | #define RM_XSTR(x) #x /* Macro hackery needed to stringify */
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| 36 | #define RM_STR(x) RM_XSTR(x)
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| 37 | #endif /* !VBOX */
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| 38 | #ifdef VBOX
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| 39 | #define RM_FRAGMENT(name, asm_code_str) \
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| 40 | extern void name ( void ); \
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| 41 | extern void name ## _end (void); \
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| 42 | __asm__( \
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| 43 | ".section .text16\n\t" \
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| 44 | ".code16\n\t" \
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| 45 | ".arch i386\n\t" \
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| 46 | ".globl " STRINGIFY(GSYM(name)) " \n\t" \
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| 47 | STRINGIFY(GSYM(name)) ":\n\t" \
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| 48 | asm_code_str "\n\t" \
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| 49 | ".globl " STRINGIFY(GSYM(name ## _end)) "\n\t" \
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| 50 | STRINGIFY(GSYM(name ## _end)) ":\n\t" \
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| 51 | ".code32\n\t" \
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| 52 | RM_SWITCH_PREV_SEGMENT "\n\t" \
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| 53 | )
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| 54 | #else /* !VBOX */
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| 55 | #define RM_FRAGMENT(name, asm_code_str) \
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| 56 | extern void name ( void ); \
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| 57 | extern void name ## _end (void); \
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| 58 | __asm__( \
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| 59 | ".section \".text16\"\n\t" \
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| 60 | ".code16\n\t" \
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| 61 | ".arch i386\n\t" \
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| 62 | ".globl " #name " \n\t" \
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| 63 | #name ":\n\t" \
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| 64 | asm_code_str "\n\t" \
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| 65 | ".globl " #name "_end\n\t" \
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| 66 | #name "_end:\n\t" \
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| 67 | ".code32\n\t" \
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| 68 | ".previous\n\t" \
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| 69 | )
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| 70 | #endif /* !VBOX */
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| 71 |
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| 72 | #define FRAGMENT_SIZE(fragment) ( (size_t) ( ( (void*) fragment ## _end )\
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| 73 | - ( (void*) (fragment) ) ) )
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| 74 |
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| 75 | /* Data structures in _prot_to_real and _real_to_prot. These
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| 76 | * structures are accessed by assembly code as well as C code.
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| 77 | */
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| 78 | typedef struct {
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| 79 | uint32_t esp;
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| 80 | uint16_t cs;
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| 81 | uint16_t ss;
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| 82 | uint32_t r2p_params;
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| 83 | } PACKED prot_to_real_params_t;
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| 84 |
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| 85 | typedef struct {
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| 86 | uint32_t ret_addr;
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| 87 | uint32_t esp;
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| 88 | uint32_t ebx;
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| 89 | uint32_t esi;
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| 90 | uint32_t edi;
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| 91 | uint32_t ebp;
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| 92 | uint32_t out_stack;
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| 93 | uint32_t out_stack_len;
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| 94 | } PACKED real_to_prot_params_t;
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| 95 |
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| 96 | /* Function prototypes: realmode.c
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| 97 | */
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| 98 | #define real_call( fragment, in_stack, out_stack ) \
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| 99 | _real_call ( fragment, FRAGMENT_SIZE(fragment), \
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| 100 | (void*)(in_stack), \
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| 101 | ( (in_stack) == NULL ? 0 : sizeof(*(in_stack)) ), \
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| 102 | (void*)(out_stack), \
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| 103 | ( (out_stack) == NULL ? 0 : sizeof(*(out_stack)) ) )
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| 104 | extern uint16_t _real_call ( void *fragment, int fragment_len,
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| 105 | void *in_stack, int in_stack_len,
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| 106 | void *out_stack, int out_stack_len );
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| 107 | /* Function prototypes: realmode_asm.S
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| 108 | */
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| 109 | extern void rm_callback_interface;
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| 110 | extern uint16_t rm_callback_interface_size;
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| 111 | extern uint32_t rm_etherboot_location;
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| 112 | extern void _rm_in_call ( void );
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| 113 | extern void _rm_in_call_far ( void );
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| 114 |
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| 115 | extern void _prot_to_real_prefix ( void );
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| 116 | extern void _prot_to_real_prefix_end ( void );
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| 117 | extern uint16_t prot_to_real_prefix_size;
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| 118 |
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| 119 | extern void _real_to_prot_suffix ( void );
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| 120 | extern void _real_to_prot_suffix_end ( void );
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| 121 | extern uint16_t real_to_prot_suffix_size;
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| 122 |
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| 123 | /* PXE assembler bits */
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| 124 | extern void pxe_callback_interface;
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| 125 | extern uint16_t pxe_callback_interface_size;
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| 126 | extern void _pxe_in_call_far ( void );
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| 127 | extern void _pxenv_in_call_far ( void );
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| 128 | extern void _pxe_intercept_int1a ( void );
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| 129 | extern segoff_t _pxe_intercepted_int1a;
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| 130 | extern segoff_t _pxe_pxenv_location;
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| 131 |
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| 132 | /* Global variables
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| 133 | */
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| 134 | extern uint32_t real_mode_stack;
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| 135 | extern size_t real_mode_stack_size;
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| 136 | extern int lock_real_mode_stack;
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| 137 |
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| 138 |
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| 139 | /* Function prototypes from basemem.c
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| 140 | */
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| 141 | #ifdef LINUXBIOS
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| 142 | /* A silly hard code that let's the code compile and work.
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| 143 | * When this becomes a problem feel free to implement
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| 144 | * something better.
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| 145 | */
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| 146 | static inline void allot_real_mode_stack(void) { real_mode_stack = 0x7c00; }
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| 147 | #else
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| 148 | void allot_real_mode_stack(void);
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| 149 | #endif
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| 150 |
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| 151 | #endif /* ASSEMBLY */
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