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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// System calls and other sys.stuff for 386, Darwin
// See http://fxr.watson.org/fxr/source/bsd/kern/syscalls.c?v=xnu-1228
// or /usr/include/sys/syscall.h (on a Mac) for system call numbers.
#include "386/asm.h"
TEXT notok(SB),7,$0
MOVL $0xf1, 0xf1
RET
// Exit the entire program (like C exit)
TEXT exit(SB),7,$0
MOVL $1, AX
INT $0x80
CALL notok(SB)
RET
// Exit this OS thread (like pthread_exit, which eventually
// calls __bsdthread_terminate).
TEXT exit1(SB),7,$0
MOVL $361, AX
INT $0x80
JAE 2(PC)
CALL notok(SB)
RET
TEXT write(SB),7,$0
MOVL $4, AX
INT $0x80
JAE 2(PC)
CALL notok(SB)
RET
TEXT runtime·mmap(SB),7,$0
MOVL $197, AX
INT $0x80
JAE 2(PC)
CALL notok(SB)
RET
TEXT sigaction(SB),7,$0
MOVL $46, AX
INT $0x80
JAE 2(PC)
CALL notok(SB)
RET
// Sigtramp's job is to call the actual signal handler.
// It is called with the following arguments on the stack:
// 0(FP) "return address" - ignored
// 4(FP) actual handler
// 8(FP) siginfo style - ignored
// 12(FP) signal number
// 16(FP) siginfo
// 20(FP) context
TEXT sigtramp(SB),7,$40
// Darwin sets GS to 0x37 on entry.
// The original GS is at 0x70(FP).
MOVL oldgs+0x70(FP), BX
MOVW BX, GS
// g = m->gsignal
get_tls(CX)
MOVL m(CX), BP
MOVL m_gsignal(BP), BP
MOVL BP, g(CX)
MOVL handler+0(FP), DI
// 4(FP) is sigstyle
MOVL signo+8(FP), AX
MOVL siginfo+12(FP), BX
MOVL context+16(FP), CX
MOVL AX, 0(SP)
MOVL BX, 4(SP)
MOVL CX, 8(SP)
CALL DI
// g = m->curg
get_tls(CX)
MOVL m(CX), BP
MOVL m_curg(BP), BP
MOVL BP, g(CX)
MOVL context+16(FP), CX
MOVL style+4(FP), BX
MOVL $0, 0(SP) // "caller PC" - ignored
MOVL CX, 4(SP)
MOVL BX, 8(SP)
MOVL $184, AX // sigreturn(ucontext, infostyle)
INT $0x80
CALL notok(SB)
RET
TEXT sigaltstack(SB),7,$0
MOVL $53, AX
INT $0x80
JAE 2(PC)
CALL notok(SB)
RET
// void bsdthread_create(void *stk, M *m, G *g, void (*fn)(void))
// System call args are: func arg stack pthread flags.
TEXT bsdthread_create(SB),7,$32
MOVL $360, AX
// 0(SP) is where the caller PC would be; kernel skips it
MOVL func+12(FP), BX
MOVL BX, 4(SP) // func
MOVL mm+4(FP), BX
MOVL BX, 8(SP) // arg
MOVL stk+0(FP), BX
MOVL BX, 12(SP) // stack
MOVL gg+8(FP), BX
MOVL BX, 16(SP) // pthread
MOVL $0x1000000, 20(SP) // flags = PTHREAD_START_CUSTOM
INT $0x80
JAE 2(PC)
CALL notok(SB)
RET
// The thread that bsdthread_create creates starts executing here,
// because we registered this function using bsdthread_register
// at startup.
// AX = "pthread" (= g)
// BX = mach thread port
// CX = "func" (= fn)
// DX = "arg" (= m)
// DI = stack top
// SI = flags (= 0x1000000)
// SP = stack - C_32_STK_ALIGN
TEXT bsdthread_start(SB),7,$0
// set up ldt 7+id to point at m->tls.
// m->tls is at m+40. newosproc left
// the m->id in tls[0].
LEAL m_tls(DX), BP
MOVL 0(BP), DI
ADDL $7, DI // m0 is LDT#7. count up.
// setldt(tls#, &tls, sizeof tls)
PUSHAL // save registers
PUSHL $32 // sizeof tls
PUSHL BP // &tls
PUSHL DI // tls #
CALL setldt(SB)
POPL AX
POPL AX
POPL AX
POPAL
// Now segment is established. Initialize m, g.
get_tls(BP)
MOVL AX, g(BP)
MOVL DX, m(BP)
MOVL BX, m_procid(DX) // m->procid = thread port (for debuggers)
CALL stackcheck(SB) // smashes AX
CALL CX // fn()
CALL exit1(SB)
RET
// void bsdthread_register(void)
// registers callbacks for threadstart (see bsdthread_create above
// and wqthread and pthsize (not used). returns 0 on success.
TEXT bsdthread_register(SB),7,$40
MOVL $366, AX
// 0(SP) is where kernel expects caller PC; ignored
MOVL $bsdthread_start(SB), 4(SP) // threadstart
MOVL $0, 8(SP) // wqthread, not used by us
MOVL $0, 12(SP) // pthsize, not used by us
MOVL $0, 16(SP) // paranoia
MOVL $0, 20(SP)
MOVL $0, 24(SP)
INT $0x80
JAE 2(PC)
CALL notok(SB)
RET
// Invoke Mach system call.
// Assumes system call number in AX,
// caller PC on stack, caller's caller PC next,
// and then the system call arguments.
//
// Can be used for BSD too, but we don't,
// because if you use this interface the BSD
// system call numbers need an extra field
// in the high 16 bits that seems to be the
// argument count in bytes but is not always.
// INT $0x80 works fine for those.
TEXT sysenter(SB),7,$0
POPL DX
MOVL SP, CX
BYTE $0x0F; BYTE $0x34; // SYSENTER
// returns to DX with SP set to CX
TEXT mach_msg_trap(SB),7,$0
MOVL $-31, AX
CALL sysenter(SB)
RET
TEXT mach_reply_port(SB),7,$0
MOVL $-26, AX
CALL sysenter(SB)
RET
TEXT mach_task_self(SB),7,$0
MOVL $-28, AX
CALL sysenter(SB)
RET
// Mach provides trap versions of the semaphore ops,
// instead of requiring the use of RPC.
// uint32 mach_semaphore_wait(uint32)
TEXT mach_semaphore_wait(SB),7,$0
MOVL $-36, AX
CALL sysenter(SB)
RET
// uint32 mach_semaphore_timedwait(uint32, uint32, uint32)
TEXT mach_semaphore_timedwait(SB),7,$0
MOVL $-38, AX
CALL sysenter(SB)
RET
// uint32 mach_semaphore_signal(uint32)
TEXT mach_semaphore_signal(SB),7,$0
MOVL $-33, AX
CALL sysenter(SB)
RET
// uint32 mach_semaphore_signal_all(uint32)
TEXT mach_semaphore_signal_all(SB),7,$0
MOVL $-34, AX
CALL sysenter(SB)
RET
/*
descriptor entry format for system call
is the native machine format, ugly as it is:
2-byte limit
3-byte base
1-byte: 0x80=present, 0x60=dpl<<5, 0x1F=type
1-byte: 0x80=limit is *4k, 0x40=32-bit operand size,
0x0F=4 more bits of limit
1 byte: 8 more bits of base
int i386_get_ldt(int, union ldt_entry *, int);
int i386_set_ldt(int, const union ldt_entry *, int);
*/
// setldt(int entry, int address, int limit)
TEXT setldt(SB),7,$32
MOVL address+4(FP), BX // aka base
MOVL limit+8(FP), CX
/*
* When linking against the system libraries,
* we use its pthread_create and let it set up %gs
* for us. When we do that, the private storage
* we get is not at 0(GS) but at 0x468(GS).
* To insulate the rest of the tool chain from this ugliness,
* 8l rewrites 0(GS) into 0x468(GS) for us.
* To accommodate that rewrite, we translate the
* address and limit here so that 0x468(GS) maps to 0(address).
*
* See ../../../../libcgo/darwin_386.c for the derivation
* of the constant.
*/
SUBL $0x468, BX
ADDL $0x468, CX
// set up data_desc
LEAL 16(SP), AX // struct data_desc
MOVL $0, 0(AX)
MOVL $0, 4(AX)
MOVW BX, 2(AX)
SHRL $16, BX
MOVB BX, 4(AX)
SHRL $8, BX
MOVB BX, 7(AX)
MOVW CX, 0(AX)
SHRL $16, CX
ANDL $0x0F, CX
ORL $0x40, CX // 32-bit operand size
MOVB CX, 6(AX)
MOVB $0xF2, 5(AX) // r/w data descriptor, dpl=3, present
// call i386_set_ldt(entry, desc, 1)
MOVL $0xffffffff, 0(SP) // auto-allocate entry and return in AX
MOVL AX, 4(SP)
MOVL $1, 8(SP)
CALL i386_set_ldt(SB)
// compute segment selector - (entry*8+7)
SHLL $3, AX
ADDL $7, AX
MOVW AX, GS
RET
TEXT i386_set_ldt(SB),7,$0
MOVL $5, AX
INT $0x82 // sic
JAE 2(PC)
CALL notok(SB)
RET
GLOBL tlsoffset(SB),$4
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