mirror of
https://github.com/jart/cosmopolitan.git
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284 lines
9.5 KiB
C
284 lines
9.5 KiB
C
/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
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│vi: set et ft=asm ts=8 sw=8 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#ifndef APE_MACROS_H_
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#define APE_MACROS_H_
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#include "libc/macros.internal.h"
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#ifdef __ASSEMBLER__
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/* clang-format off */
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/**
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* @fileoverview Macros relevant to αcτµαlly pδrταblε εxεcµταblε.
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*/
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// Calls near (i.e. pc+pcrel<64kB) FUNCTION.
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// @mode long,legacy,real
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// @cost 9 bytes overhead
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.macro rlcall function:req
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.byte 0x50 # push %[er]ax
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.byte 0xb8,0,0 # mov $?,%[e]ax
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jmp 911f
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.byte 0x58 # pop %[er]ax
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.byte 0xe8 # call Jvds
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.long \function\()-.-4
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jmp 912f
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911: .byte 0x58 # pop %[er]ax
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.byte 0xe8 # call Jvds
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.short \function\()-.-2
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912:
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.endm
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// Loads far (i.e. <1mb) abs constexpr ADDRESS into ES:DI+EDX+RDX.
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// @mode long,legacy,real
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.macro movesdi address:req
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.byte 0xbf # mov $0x????xxxx,%[e]di
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.short \address>>4
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.byte 0x8e,0xc7 # mov %di,%es
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.byte 0xbf # mov $0x????xxxx,%[e]di
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.short \address&0xf
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jmp 297f
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.byte 0xbf # mov $0x????xxxx,%edi
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.long \address
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297:
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.endm
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// Loads 16-bit CONSTEXPR into Qw-register w/ optional zero-extend.
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// @mode long,legacy,real
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.macro bbmov constexpr:req abcd abcd.hi:req abcd.lo:req
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.ifnb \abcd
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.if (\constexpr)<128 && (\constexpr)>=0
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pushpop \constexpr,\abcd
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.exitm
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.endif
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.endif
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movb $(\constexpr)>>8&0xff,\abcd.hi
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movb $(\constexpr)&0xff,\abcd.lo
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.endm
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// Compares 16-bit CONSTEXPR with Qw-register.
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// @mode long,legacy,real
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.macro bbcmp constexpr:req abcd.hi:req abcd.lo:req
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cmpb $(\constexpr)>>8&0xff,\abcd.hi
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jnz 387f
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cmpb $(\constexpr)&0xff,\abcd.lo
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387:
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.endm
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// Adds 16-bit CONSTEXPR to Qw-register.
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// @mode long,legacy,real
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.macro bbadd constexpr:req abcd.hi:req abcd.lo:req
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addb $(\constexpr)&0xff,\abcd.lo
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.if (\constexpr) != 0
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adcb $(\constexpr)>>8&0xff,\abcd.hi
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.endif
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.endm
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// Subtracts 16-bit CONSTEXPR from Qw-register.
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// @mode long,legacy,real
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.macro bbsub constexpr:req abcd.hi:req abcd.lo:req
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subb $(\constexpr)&0xff,\abcd.lo
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.if (\constexpr) != 0
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sbbb $(\constexpr)>>8&0xff,\abcd.hi
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.endif
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.endm
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// Ands Qw-register with 16-bit CONSTEXPR.
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// @mode long,legacy,real
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.macro bband constexpr:req abcd.hi:req abcd.lo:req
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.if ((\constexpr)&0xff) != 0xff || ((\constexpr)>>8&0xff) == 0xff
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andb $(\constexpr)&0xff,\abcd.lo
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.endif
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.if ((\constexpr)>>8&0xff) != 0xff
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andb $(\constexpr)>>8&0xff,\abcd.hi
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.endif
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.endm
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// Ors Qw-register with 16-bit CONSTEXPR.
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// @mode long,legacy,real
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.macro bbor constexpr:req abcd.hi:req abcd.lo:req
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.if ((\constexpr)&0xff) != 0 || ((\constexpr)>>8&0xff) != 0
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orb $(\constexpr)&0xff,\abcd.lo
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.endif
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.if ((\constexpr)>>8&0xff) != 0
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orb $(\constexpr)>>8&0xff,\abcd.hi
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.endif
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.endm
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// Performs ACTION only if in real mode.
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// @mode long,legacy,real
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.macro rlo clobber:req action:vararg
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990: mov $0,\clobber
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.if .-990b!=3
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.error "bad clobber or assembler mode"
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.endif
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991: \action
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.rept 2-(.-991b)
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nop
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.endr
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.if .-991b!=2
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.error "ACTION must be 1-2 bytes"
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.endif
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.endm
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// Initializes real mode stack.
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// The most holiest of holy code.
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// @mode real
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// @see www.pcjs.org/pubs/pc/reference/intel/8086/
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.macro rlstack seg:req addr:req
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cli
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mov \seg,%ss
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mov \addr,%sp
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sti
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.endm
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// Symbolic Linker-Defined Binary Content.
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.macro .stub name:req kind:req default type=@object
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.ifnb \default
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.equ \name,\default
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.endif
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.\kind \name
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.type \name,\type
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.weak \name
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.hidden \name
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.endm
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// Symbolic Linker-Defined Binary-Encoded-Bourne Content.
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// @param units is the number of encoded 32-bit values to insert,
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// e.g. \000 can be encoded as 0x3030305c.
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.macro .shstub name:req num:req
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ss \name,0
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.if \num>1
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ss \name,1
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.if \num>2
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ss \name,2
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ss \name,3
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.if \num>4
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ss \name,4
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ss \name,5
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ss \name,6
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ss \name,7
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.endif
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.endif
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.endif
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.endm
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.macro ss name n
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.stub \name\()_bcs\n,long
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.endm
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// Task State Segment Descriptor Entries.
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.macro .tssdescstub name:req
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.stub \name\()_desc_ent0,quad
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.stub \name\()_desc_ent1,quad
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.endm
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/* clang-format on */
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#elif defined(__LINKER__)
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#define BCX_NIBBLE(X) ((((X)&0xf) > 0x9) ? ((X)&0xf) + 0x37 : ((X)&0xf) + 0x30)
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#define BCX_OCTET(X) ((BCX_NIBBLE((X) >> 4) << 8) | (BCX_NIBBLE((X) >> 0) << 0))
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#define BCX_INT16(X) ((BCX_OCTET((X) >> 8) << 16) | (BCX_OCTET((X) >> 0) << 0))
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#define BCXSTUB(SYM, X) \
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HIDDEN(SYM##_bcx0 = BCX_INT16((X) >> 48)); \
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HIDDEN(SYM##_bcx1 = BCX_INT16((X) >> 32)); \
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HIDDEN(SYM##_bcx2 = BCX_INT16((X) >> 16)); \
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HIDDEN(SYM##_bcx3 = BCX_INT16((X) >> 0))
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/**
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* Binary coded backslash octet support.
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*
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* <p>This allows linker scripts to generate printf commands.
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*/
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#define BCO_OCTET(X) (((X)&0x7) + 0x30)
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#define BCOB_UNIT(X) \
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((BCO_OCTET((X) >> 0) << 24) | (BCO_OCTET((X) >> 3) << 16) | \
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(BCO_OCTET(((X)&0xff) >> 6) << 8) | 0x5c)
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#define PFBYTE(SYM, X, I) HIDDEN(SYM##_bcs##I = BCOB_UNIT((X) >> ((I)*8)))
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#define PFSTUB2(SYM, X) \
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HIDDEN(SYM = (X)); \
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PFBYTE(SYM, X, 0); \
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PFBYTE(SYM, X, 1)
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#define PFSTUB4(SYM, X) \
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PFSTUB2(SYM, X); \
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PFBYTE(SYM, X, 2); \
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PFBYTE(SYM, X, 3)
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#define PFSTUB8(SYM, X) \
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PFSTUB4(SYM, X); \
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PFBYTE(SYM, X, 4); \
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PFBYTE(SYM, X, 5); \
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PFBYTE(SYM, X, 6); \
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PFBYTE(SYM, X, 7)
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/**
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* Binary coded decimal support.
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*
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* <p>This allows linker scripts to generate dd commands, e.g. ape.lds.
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* There are a few ways to pad each number to the necessary 8 bytes.
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* Spaces cannot be prepended because busybox refuses to parse them.
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* Zeros cannot be prepended because Mac will take numbers as octal.
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* That leaves appending spaces. The user's shell ought to treat any
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* unquoted run of spaces as if there was only one, so this is safe.
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*/
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#define SHSTUB2(SYM, X) \
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HIDDEN(SYM##_bcs0 = BCD_LEFT(X)); \
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HIDDEN(SYM##_bcs1 = BCD_RIGHT(X))
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#define BCD_SMEAR(X) ((X) + (X) * 10000)
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#define BCD_LEFT(X) \
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(((X)) < 10000 ? BCD_RIGHT(BCD_SMEAR(X)) | 0x10 \
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: (X) < 100000 ? BCD_RIGHT(BCD_SMEAR((X) / 10)) \
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: (X) < 1000000 ? BCD_RIGHT(BCD_SMEAR((X) / 100)) \
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: (X) < 10000000 ? BCD_RIGHT(BCD_SMEAR((X) / 1000)) \
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: (X) < 100000000 ? BCD_RIGHT(BCD_SMEAR((X) / 10000)) \
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: 0xffffffffffffffff)
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#define BCD_RIGHT(X) \
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(((X)) < 10000 ? 0x20202020 \
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: (X) < 100000 ? 0x20202030 + \
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(X) % 10 \
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: (X) < 1000000 ? 0x20203030 + \
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((X) / 10) % 10 + \
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(X) % 10 * 0x100 \
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: (X) < 10000000 ? 0x20303030 + \
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((X) / 100) % 10 + \
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((X) / 10) % 10 * 0x100 + \
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(X) % 10 * 0x10000 \
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: (X) < 100000000 ? 0x30303030 + \
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((X) / 1000) % 10 + \
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((X) / 100) % 10 * 0x100 + \
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((X) / 10) % 10 * 0x10000 + \
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(X) % 10 * 0x1000000 \
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: 0xffffffffffffffff)
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/**
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* Laying out the GDT entries for a TSS for bare metal operation.
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*/
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#define TSSDESCSTUB2(SYM, BASE, LIM) \
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HIDDEN(SYM##_desc_ent0 = TSSDESC_ENT0(BASE, LIM)); \
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HIDDEN(SYM##_desc_ent1 = TSSDESC_ENT1(BASE)); \
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ASSERT((LIM) >= 0 && (LIM) <= 0xffff, "bare metal TSS is suspiciously fat")
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#define TSSDESC_ENT0(BASE, LIM) \
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(((LIM) << 0 & 0x000000000000ffff) | \
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((BASE) << 16 & 0x000000ffffff0000) | \
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0x89 << 40 | \
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((LIM) >> 16 << 48 & 0x000f000000000000) | \
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0x2 << 52 | \
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((BASE) >> 24 << 56 & 0xff00000000000000))
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#define TSSDESC_ENT1(BASE) \
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((BASE) >> 32 << 0 & 0x00000000ffffffff)
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#endif /* __ASSEMBLER__ */
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#endif /* APE_MACROS_H_ */
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