File:  [Qemu by Fabrice Bellard] / qemu / dis-asm.h
Revision 1.1.1.9 (vendor branch): download - view: text, annotated - select for diffs
Tue Apr 24 18:33:43 2018 UTC (2 years, 3 months ago) by root
Branches: qemu, MAIN
CVS tags: qemu0150, qemu0141, qemu0140, HEAD
qemu 0.14.0

    1: /* Interface between the opcode library and its callers.
    2:    Written by Cygnus Support, 1993.
    3: 
    4:    The opcode library (libopcodes.a) provides instruction decoders for
    5:    a large variety of instruction sets, callable with an identical
    6:    interface, for making instruction-processing programs more independent
    7:    of the instruction set being processed.  */
    8: 
    9: #ifndef DIS_ASM_H
   10: #define DIS_ASM_H
   11: 
   12: #include "qemu-common.h"
   13: 
   14: typedef void *PTR;
   15: typedef uint64_t bfd_vma;
   16: typedef int64_t bfd_signed_vma;
   17: typedef uint8_t bfd_byte;
   18: #define sprintf_vma(s,x) sprintf (s, "%0" PRIx64, x)
   19: #define snprintf_vma(s,ss,x) snprintf (s, ss, "%0" PRIx64, x)
   20: 
   21: #define BFD64
   22: 
   23: enum bfd_flavour {
   24:   bfd_target_unknown_flavour,
   25:   bfd_target_aout_flavour,
   26:   bfd_target_coff_flavour,
   27:   bfd_target_ecoff_flavour,
   28:   bfd_target_elf_flavour,
   29:   bfd_target_ieee_flavour,
   30:   bfd_target_nlm_flavour,
   31:   bfd_target_oasys_flavour,
   32:   bfd_target_tekhex_flavour,
   33:   bfd_target_srec_flavour,
   34:   bfd_target_ihex_flavour,
   35:   bfd_target_som_flavour,
   36:   bfd_target_os9k_flavour,
   37:   bfd_target_versados_flavour,
   38:   bfd_target_msdos_flavour,
   39:   bfd_target_evax_flavour
   40: };
   41: 
   42: enum bfd_endian { BFD_ENDIAN_BIG, BFD_ENDIAN_LITTLE, BFD_ENDIAN_UNKNOWN };
   43: 
   44: enum bfd_architecture
   45: {
   46:   bfd_arch_unknown,    /* File arch not known */
   47:   bfd_arch_obscure,    /* Arch known, not one of these */
   48:   bfd_arch_m68k,       /* Motorola 68xxx */
   49: #define bfd_mach_m68000 1
   50: #define bfd_mach_m68008 2
   51: #define bfd_mach_m68010 3
   52: #define bfd_mach_m68020 4
   53: #define bfd_mach_m68030 5
   54: #define bfd_mach_m68040 6
   55: #define bfd_mach_m68060 7
   56: #define bfd_mach_cpu32  8
   57: #define bfd_mach_mcf5200  9
   58: #define bfd_mach_mcf5206e 10
   59: #define bfd_mach_mcf5307  11
   60: #define bfd_mach_mcf5407  12
   61: #define bfd_mach_mcf528x  13
   62: #define bfd_mach_mcfv4e   14
   63: #define bfd_mach_mcf521x   15
   64: #define bfd_mach_mcf5249   16
   65: #define bfd_mach_mcf547x   17
   66: #define bfd_mach_mcf548x   18
   67:   bfd_arch_vax,        /* DEC Vax */
   68:   bfd_arch_i960,       /* Intel 960 */
   69:      /* The order of the following is important.
   70:        lower number indicates a machine type that
   71:        only accepts a subset of the instructions
   72:        available to machines with higher numbers.
   73:        The exception is the "ca", which is
   74:        incompatible with all other machines except
   75:        "core". */
   76: 
   77: #define bfd_mach_i960_core      1
   78: #define bfd_mach_i960_ka_sa     2
   79: #define bfd_mach_i960_kb_sb     3
   80: #define bfd_mach_i960_mc        4
   81: #define bfd_mach_i960_xa        5
   82: #define bfd_mach_i960_ca        6
   83: #define bfd_mach_i960_jx        7
   84: #define bfd_mach_i960_hx        8
   85: 
   86:   bfd_arch_a29k,       /* AMD 29000 */
   87:   bfd_arch_sparc,      /* SPARC */
   88: #define bfd_mach_sparc                 1
   89: /* The difference between v8plus and v9 is that v9 is a true 64 bit env.  */
   90: #define bfd_mach_sparc_sparclet        2
   91: #define bfd_mach_sparc_sparclite       3
   92: #define bfd_mach_sparc_v8plus          4
   93: #define bfd_mach_sparc_v8plusa         5 /* with ultrasparc add'ns.  */
   94: #define bfd_mach_sparc_sparclite_le    6
   95: #define bfd_mach_sparc_v9              7
   96: #define bfd_mach_sparc_v9a             8 /* with ultrasparc add'ns.  */
   97: #define bfd_mach_sparc_v8plusb         9 /* with cheetah add'ns.  */
   98: #define bfd_mach_sparc_v9b             10 /* with cheetah add'ns.  */
   99: /* Nonzero if MACH has the v9 instruction set.  */
  100: #define bfd_mach_sparc_v9_p(mach) \
  101:   ((mach) >= bfd_mach_sparc_v8plus && (mach) <= bfd_mach_sparc_v9b \
  102:    && (mach) != bfd_mach_sparc_sparclite_le)
  103:   bfd_arch_mips,       /* MIPS Rxxxx */
  104: #define bfd_mach_mips3000              3000
  105: #define bfd_mach_mips3900              3900
  106: #define bfd_mach_mips4000              4000
  107: #define bfd_mach_mips4010              4010
  108: #define bfd_mach_mips4100              4100
  109: #define bfd_mach_mips4300              4300
  110: #define bfd_mach_mips4400              4400
  111: #define bfd_mach_mips4600              4600
  112: #define bfd_mach_mips4650              4650
  113: #define bfd_mach_mips5000              5000
  114: #define bfd_mach_mips6000              6000
  115: #define bfd_mach_mips8000              8000
  116: #define bfd_mach_mips10000             10000
  117: #define bfd_mach_mips16                16
  118:   bfd_arch_i386,       /* Intel 386 */
  119: #define bfd_mach_i386_i386 0
  120: #define bfd_mach_i386_i8086 1
  121: #define bfd_mach_i386_i386_intel_syntax 2
  122: #define bfd_mach_x86_64 3
  123: #define bfd_mach_x86_64_intel_syntax 4
  124:   bfd_arch_we32k,      /* AT&T WE32xxx */
  125:   bfd_arch_tahoe,      /* CCI/Harris Tahoe */
  126:   bfd_arch_i860,       /* Intel 860 */
  127:   bfd_arch_romp,       /* IBM ROMP PC/RT */
  128:   bfd_arch_alliant,    /* Alliant */
  129:   bfd_arch_convex,     /* Convex */
  130:   bfd_arch_m88k,       /* Motorola 88xxx */
  131:   bfd_arch_pyramid,    /* Pyramid Technology */
  132:   bfd_arch_h8300,      /* Hitachi H8/300 */
  133: #define bfd_mach_h8300   1
  134: #define bfd_mach_h8300h  2
  135: #define bfd_mach_h8300s  3
  136:   bfd_arch_powerpc,    /* PowerPC */
  137: #define bfd_mach_ppc           0
  138: #define bfd_mach_ppc64         1
  139: #define bfd_mach_ppc_403       403
  140: #define bfd_mach_ppc_403gc     4030
  141: #define bfd_mach_ppc_e500      500
  142: #define bfd_mach_ppc_505       505
  143: #define bfd_mach_ppc_601       601
  144: #define bfd_mach_ppc_602       602
  145: #define bfd_mach_ppc_603       603
  146: #define bfd_mach_ppc_ec603e    6031
  147: #define bfd_mach_ppc_604       604
  148: #define bfd_mach_ppc_620       620
  149: #define bfd_mach_ppc_630       630
  150: #define bfd_mach_ppc_750       750
  151: #define bfd_mach_ppc_860       860
  152: #define bfd_mach_ppc_a35       35
  153: #define bfd_mach_ppc_rs64ii    642
  154: #define bfd_mach_ppc_rs64iii   643
  155: #define bfd_mach_ppc_7400      7400
  156:   bfd_arch_rs6000,     /* IBM RS/6000 */
  157:   bfd_arch_hppa,       /* HP PA RISC */
  158: #define bfd_mach_hppa10        10
  159: #define bfd_mach_hppa11        11
  160: #define bfd_mach_hppa20        20
  161: #define bfd_mach_hppa20w       25
  162:   bfd_arch_d10v,       /* Mitsubishi D10V */
  163:   bfd_arch_z8k,        /* Zilog Z8000 */
  164: #define bfd_mach_z8001         1
  165: #define bfd_mach_z8002         2
  166:   bfd_arch_h8500,      /* Hitachi H8/500 */
  167:   bfd_arch_sh,         /* Hitachi SH */
  168: #define bfd_mach_sh            1
  169: #define bfd_mach_sh2        0x20
  170: #define bfd_mach_sh_dsp     0x2d
  171: #define bfd_mach_sh2a       0x2a
  172: #define bfd_mach_sh2a_nofpu 0x2b
  173: #define bfd_mach_sh2e       0x2e
  174: #define bfd_mach_sh3        0x30
  175: #define bfd_mach_sh3_nommu  0x31
  176: #define bfd_mach_sh3_dsp    0x3d
  177: #define bfd_mach_sh3e       0x3e
  178: #define bfd_mach_sh4        0x40
  179: #define bfd_mach_sh4_nofpu  0x41
  180: #define bfd_mach_sh4_nommu_nofpu  0x42
  181: #define bfd_mach_sh4a       0x4a
  182: #define bfd_mach_sh4a_nofpu 0x4b
  183: #define bfd_mach_sh4al_dsp  0x4d
  184: #define bfd_mach_sh5        0x50
  185:   bfd_arch_alpha,      /* Dec Alpha */
  186: #define bfd_mach_alpha 1
  187:   bfd_arch_arm,        /* Advanced Risc Machines ARM */
  188: #define bfd_mach_arm_unknown	0
  189: #define bfd_mach_arm_2		1
  190: #define bfd_mach_arm_2a		2
  191: #define bfd_mach_arm_3		3
  192: #define bfd_mach_arm_3M 	4
  193: #define bfd_mach_arm_4 		5
  194: #define bfd_mach_arm_4T 	6
  195: #define bfd_mach_arm_5 		7
  196: #define bfd_mach_arm_5T		8
  197: #define bfd_mach_arm_5TE	9
  198: #define bfd_mach_arm_XScale	10
  199: #define bfd_mach_arm_ep9312	11
  200: #define bfd_mach_arm_iWMMXt	12
  201: #define bfd_mach_arm_iWMMXt2	13
  202:   bfd_arch_ns32k,      /* National Semiconductors ns32000 */
  203:   bfd_arch_w65,        /* WDC 65816 */
  204:   bfd_arch_tic30,      /* Texas Instruments TMS320C30 */
  205:   bfd_arch_v850,       /* NEC V850 */
  206: #define bfd_mach_v850          0
  207:   bfd_arch_arc,        /* Argonaut RISC Core */
  208: #define bfd_mach_arc_base 0
  209:   bfd_arch_m32r,       /* Mitsubishi M32R/D */
  210: #define bfd_mach_m32r          0  /* backwards compatibility */
  211:   bfd_arch_mn10200,    /* Matsushita MN10200 */
  212:   bfd_arch_mn10300,    /* Matsushita MN10300 */
  213:   bfd_arch_cris,       /* Axis CRIS */
  214: #define bfd_mach_cris_v0_v10   255
  215: #define bfd_mach_cris_v32      32
  216: #define bfd_mach_cris_v10_v32  1032
  217:   bfd_arch_microblaze, /* Xilinx MicroBlaze.  */
  218:   bfd_arch_ia64,      /* HP/Intel ia64 */
  219: #define bfd_mach_ia64_elf64    64
  220: #define bfd_mach_ia64_elf32    32
  221:   bfd_arch_last
  222:   };
  223: #define bfd_mach_s390_31 31
  224: #define bfd_mach_s390_64 64
  225: 
  226: typedef struct symbol_cache_entry
  227: {
  228:     const char *name;
  229:     union
  230:     {
  231:         PTR p;
  232:         bfd_vma i;
  233:     } udata;
  234: } asymbol;
  235: 
  236: enum dis_insn_type {
  237:   dis_noninsn,			/* Not a valid instruction */
  238:   dis_nonbranch,		/* Not a branch instruction */
  239:   dis_branch,			/* Unconditional branch */
  240:   dis_condbranch,		/* Conditional branch */
  241:   dis_jsr,			/* Jump to subroutine */
  242:   dis_condjsr,			/* Conditional jump to subroutine */
  243:   dis_dref,			/* Data reference instruction */
  244:   dis_dref2			/* Two data references in instruction */
  245: };
  246: 
  247: /* This struct is passed into the instruction decoding routine,
  248:    and is passed back out into each callback.  The various fields are used
  249:    for conveying information from your main routine into your callbacks,
  250:    for passing information into the instruction decoders (such as the
  251:    addresses of the callback functions), or for passing information
  252:    back from the instruction decoders to their callers.
  253: 
  254:    It must be initialized before it is first passed; this can be done
  255:    by hand, or using one of the initialization macros below.  */
  256: 
  257: typedef struct disassemble_info {
  258:   fprintf_function fprintf_func;
  259:   FILE *stream;
  260:   PTR application_data;
  261: 
  262:   /* Target description.  We could replace this with a pointer to the bfd,
  263:      but that would require one.  There currently isn't any such requirement
  264:      so to avoid introducing one we record these explicitly.  */
  265:   /* The bfd_flavour.  This can be bfd_target_unknown_flavour.  */
  266:   enum bfd_flavour flavour;
  267:   /* The bfd_arch value.  */
  268:   enum bfd_architecture arch;
  269:   /* The bfd_mach value.  */
  270:   unsigned long mach;
  271:   /* Endianness (for bi-endian cpus).  Mono-endian cpus can ignore this.  */
  272:   enum bfd_endian endian;
  273: 
  274:   /* An array of pointers to symbols either at the location being disassembled
  275:      or at the start of the function being disassembled.  The array is sorted
  276:      so that the first symbol is intended to be the one used.  The others are
  277:      present for any misc. purposes.  This is not set reliably, but if it is
  278:      not NULL, it is correct.  */
  279:   asymbol **symbols;
  280:   /* Number of symbols in array.  */
  281:   int num_symbols;
  282: 
  283:   /* For use by the disassembler.
  284:      The top 16 bits are reserved for public use (and are documented here).
  285:      The bottom 16 bits are for the internal use of the disassembler.  */
  286:   unsigned long flags;
  287: #define INSN_HAS_RELOC	0x80000000
  288:   PTR private_data;
  289: 
  290:   /* Function used to get bytes to disassemble.  MEMADDR is the
  291:      address of the stuff to be disassembled, MYADDR is the address to
  292:      put the bytes in, and LENGTH is the number of bytes to read.
  293:      INFO is a pointer to this struct.
  294:      Returns an errno value or 0 for success.  */
  295:   int (*read_memory_func)
  296:     (bfd_vma memaddr, bfd_byte *myaddr, int length,
  297: 	     struct disassemble_info *info);
  298: 
  299:   /* Function which should be called if we get an error that we can't
  300:      recover from.  STATUS is the errno value from read_memory_func and
  301:      MEMADDR is the address that we were trying to read.  INFO is a
  302:      pointer to this struct.  */
  303:   void (*memory_error_func)
  304:     (int status, bfd_vma memaddr, struct disassemble_info *info);
  305: 
  306:   /* Function called to print ADDR.  */
  307:   void (*print_address_func)
  308:     (bfd_vma addr, struct disassemble_info *info);
  309: 
  310:   /* Function called to determine if there is a symbol at the given ADDR.
  311:      If there is, the function returns 1, otherwise it returns 0.
  312:      This is used by ports which support an overlay manager where
  313:      the overlay number is held in the top part of an address.  In
  314:      some circumstances we want to include the overlay number in the
  315:      address, (normally because there is a symbol associated with
  316:      that address), but sometimes we want to mask out the overlay bits.  */
  317:   int (* symbol_at_address_func)
  318:     (bfd_vma addr, struct disassemble_info * info);
  319: 
  320:   /* These are for buffer_read_memory.  */
  321:   bfd_byte *buffer;
  322:   bfd_vma buffer_vma;
  323:   int buffer_length;
  324: 
  325:   /* This variable may be set by the instruction decoder.  It suggests
  326:       the number of bytes objdump should display on a single line.  If
  327:       the instruction decoder sets this, it should always set it to
  328:       the same value in order to get reasonable looking output.  */
  329:   int bytes_per_line;
  330: 
  331:   /* the next two variables control the way objdump displays the raw data */
  332:   /* For example, if bytes_per_line is 8 and bytes_per_chunk is 4, the */
  333:   /* output will look like this:
  334:      00:   00000000 00000000
  335:      with the chunks displayed according to "display_endian". */
  336:   int bytes_per_chunk;
  337:   enum bfd_endian display_endian;
  338: 
  339:   /* Results from instruction decoders.  Not all decoders yet support
  340:      this information.  This info is set each time an instruction is
  341:      decoded, and is only valid for the last such instruction.
  342: 
  343:      To determine whether this decoder supports this information, set
  344:      insn_info_valid to 0, decode an instruction, then check it.  */
  345: 
  346:   char insn_info_valid;		/* Branch info has been set. */
  347:   char branch_delay_insns;	/* How many sequential insn's will run before
  348: 				   a branch takes effect.  (0 = normal) */
  349:   char data_size;		/* Size of data reference in insn, in bytes */
  350:   enum dis_insn_type insn_type;	/* Type of instruction */
  351:   bfd_vma target;		/* Target address of branch or dref, if known;
  352: 				   zero if unknown.  */
  353:   bfd_vma target2;		/* Second target address for dref2 */
  354: 
  355:   /* Command line options specific to the target disassembler.  */
  356:   char * disassembler_options;
  357: 
  358: } disassemble_info;
  359: 
  360: 
  361: /* Standard disassemblers.  Disassemble one instruction at the given
  362:    target address.  Return number of bytes processed.  */
  363: typedef int (*disassembler_ftype) (bfd_vma, disassemble_info *);
  364: 
  365: int print_insn_big_mips         (bfd_vma, disassemble_info*);
  366: int print_insn_little_mips      (bfd_vma, disassemble_info*);
  367: int print_insn_i386             (bfd_vma, disassemble_info*);
  368: int print_insn_m68k             (bfd_vma, disassemble_info*);
  369: int print_insn_z8001            (bfd_vma, disassemble_info*);
  370: int print_insn_z8002            (bfd_vma, disassemble_info*);
  371: int print_insn_h8300            (bfd_vma, disassemble_info*);
  372: int print_insn_h8300h           (bfd_vma, disassemble_info*);
  373: int print_insn_h8300s           (bfd_vma, disassemble_info*);
  374: int print_insn_h8500            (bfd_vma, disassemble_info*);
  375: int print_insn_alpha            (bfd_vma, disassemble_info*);
  376: disassembler_ftype arc_get_disassembler (int, int);
  377: int print_insn_arm              (bfd_vma, disassemble_info*);
  378: int print_insn_sparc            (bfd_vma, disassemble_info*);
  379: int print_insn_big_a29k         (bfd_vma, disassemble_info*);
  380: int print_insn_little_a29k      (bfd_vma, disassemble_info*);
  381: int print_insn_i960             (bfd_vma, disassemble_info*);
  382: int print_insn_sh               (bfd_vma, disassemble_info*);
  383: int print_insn_shl              (bfd_vma, disassemble_info*);
  384: int print_insn_hppa             (bfd_vma, disassemble_info*);
  385: int print_insn_m32r             (bfd_vma, disassemble_info*);
  386: int print_insn_m88k             (bfd_vma, disassemble_info*);
  387: int print_insn_mn10200          (bfd_vma, disassemble_info*);
  388: int print_insn_mn10300          (bfd_vma, disassemble_info*);
  389: int print_insn_ns32k            (bfd_vma, disassemble_info*);
  390: int print_insn_big_powerpc      (bfd_vma, disassemble_info*);
  391: int print_insn_little_powerpc   (bfd_vma, disassemble_info*);
  392: int print_insn_rs6000           (bfd_vma, disassemble_info*);
  393: int print_insn_w65              (bfd_vma, disassemble_info*);
  394: int print_insn_d10v             (bfd_vma, disassemble_info*);
  395: int print_insn_v850             (bfd_vma, disassemble_info*);
  396: int print_insn_tic30            (bfd_vma, disassemble_info*);
  397: int print_insn_ppc              (bfd_vma, disassemble_info*);
  398: int print_insn_s390             (bfd_vma, disassemble_info*);
  399: int print_insn_crisv32          (bfd_vma, disassemble_info*);
  400: int print_insn_crisv10          (bfd_vma, disassemble_info*);
  401: int print_insn_microblaze       (bfd_vma, disassemble_info*);
  402: int print_insn_ia64             (bfd_vma, disassemble_info*);
  403: 
  404: #if 0
  405: /* Fetch the disassembler for a given BFD, if that support is available.  */
  406: disassembler_ftype disassembler(bfd *);
  407: #endif
  408: 
  409: 
  410: /* This block of definitions is for particular callers who read instructions
  411:    into a buffer before calling the instruction decoder.  */
  412: 
  413: /* Here is a function which callers may wish to use for read_memory_func.
  414:    It gets bytes from a buffer.  */
  415: int buffer_read_memory(bfd_vma, bfd_byte *, int, struct disassemble_info *);
  416: 
  417: /* This function goes with buffer_read_memory.
  418:    It prints a message using info->fprintf_func and info->stream.  */
  419: void perror_memory(int, bfd_vma, struct disassemble_info *);
  420: 
  421: 
  422: /* Just print the address in hex.  This is included for completeness even
  423:    though both GDB and objdump provide their own (to print symbolic
  424:    addresses).  */
  425: void generic_print_address(bfd_vma, struct disassemble_info *);
  426: 
  427: /* Always true.  */
  428: int generic_symbol_at_address(bfd_vma, struct disassemble_info *);
  429: 
  430: /* Macro to initialize a disassemble_info struct.  This should be called
  431:    by all applications creating such a struct.  */
  432: #define INIT_DISASSEMBLE_INFO(INFO, STREAM, FPRINTF_FUNC) \
  433:   (INFO).flavour = bfd_target_unknown_flavour, \
  434:   (INFO).arch = bfd_arch_unknown, \
  435:   (INFO).mach = 0, \
  436:   (INFO).endian = BFD_ENDIAN_UNKNOWN, \
  437:   INIT_DISASSEMBLE_INFO_NO_ARCH(INFO, STREAM, FPRINTF_FUNC)
  438: 
  439: /* Call this macro to initialize only the internal variables for the
  440:    disassembler.  Architecture dependent things such as byte order, or machine
  441:    variant are not touched by this macro.  This makes things much easier for
  442:    GDB which must initialize these things separately.  */
  443: 
  444: #define INIT_DISASSEMBLE_INFO_NO_ARCH(INFO, STREAM, FPRINTF_FUNC) \
  445:   (INFO).fprintf_func = (FPRINTF_FUNC), \
  446:   (INFO).stream = (STREAM), \
  447:   (INFO).symbols = NULL, \
  448:   (INFO).num_symbols = 0, \
  449:   (INFO).private_data = NULL, \
  450:   (INFO).buffer = NULL, \
  451:   (INFO).buffer_vma = 0, \
  452:   (INFO).buffer_length = 0, \
  453:   (INFO).read_memory_func = buffer_read_memory, \
  454:   (INFO).memory_error_func = perror_memory, \
  455:   (INFO).print_address_func = generic_print_address, \
  456:   (INFO).symbol_at_address_func = generic_symbol_at_address, \
  457:   (INFO).flags = 0, \
  458:   (INFO).bytes_per_line = 0, \
  459:   (INFO).bytes_per_chunk = 0, \
  460:   (INFO).display_endian = BFD_ENDIAN_UNKNOWN, \
  461:   (INFO).disassembler_options = NULL, \
  462:   (INFO).insn_info_valid = 0
  463: 
  464: #define _(x) x
  465: #define ATTRIBUTE_UNUSED __attribute__((unused))
  466: 
  467: /* from libbfd */
  468: 
  469: bfd_vma bfd_getl64 (const bfd_byte *addr);
  470: bfd_vma bfd_getl32 (const bfd_byte *addr);
  471: bfd_vma bfd_getb32 (const bfd_byte *addr);
  472: bfd_vma bfd_getl16 (const bfd_byte *addr);
  473: bfd_vma bfd_getb16 (const bfd_byte *addr);
  474: typedef bool bfd_boolean;
  475: 
  476: #endif /* ! defined (DIS_ASM_H) */

unix.superglobalmegacorp.com