l.s

著名操作系统Plan 9的第三版的部分核心源代码。现在很难找到了。Plan 9是bell实验室开发的Unix后继者。

TEXT fprestore(SB), $0				/* enable and restore state */
	FPON
	MOVL	p+0(FP), AX
	FRSTOR	0(AX)
	WAIT
	RET

TEXT fpstatus(SB), $0				/* get floating point status */
	FSTSW	AX
	RET

TEXT fpenv(SB), $0				/* save state without waiting */
	MOVL	p+0(FP), AX
	FSTENV	0(AX)
	RET

/*
 */
TEXT splhi(SB), $0
	MOVL	$(MACHADDR+0x04), AX 		/* save PC in m->splpc */
	MOVL	(SP), BX
	MOVL	BX, (AX)

	PUSHFL
	POPL	AX
	CLI
	RET

TEXT spllo(SB), $0
	PUSHFL
	POPL	AX
	STI
	RET

TEXT splx(SB), $0
	MOVL	$(MACHADDR+0x04), AX 		/* save PC in m->splpc */
	MOVL	(SP), BX
	MOVL	BX, (AX)

TEXT splxpc(SB), $0				/* for iunlock */
	MOVL	s+0(FP), AX
	PUSHL	AX
	POPFL
	RET

TEXT spldone(SB), $0
	RET

TEXT islo(SB), $0
	PUSHFL
	POPL	AX
	ANDL	$0x200, AX			/* interrupt enable flag */
	RET

/*
 * Test-And-Set
 */
TEXT tas(SB), $0
	MOVL	$0xDEADDEAD, AX
	MOVL	lock+0(FP), BX
	XCHGL	AX, (BX)			/* lock->key */
	RET

TEXT wbflush(SB), $0
	CPUID
	RET

TEXT xchgw(SB), $0
	MOVL	v+4(FP), AX
	MOVL	p+0(FP), BX
	XCHGW	AX, (BX)
	RET

/*
TEXT xchgl(SB), $0
	MOVL	v+4(FP), AX
	MOVL	p+0(FP), BX
	XCHGL	AX, (BX)
	RET
 */

/*
 *  label consists of a stack pointer and a PC
 */
TEXT gotolabel(SB), $0
	MOVL	label+0(FP), AX
	MOVL	0(AX), SP			/* restore sp */
	MOVL	4(AX), AX			/* put return pc on the stack */
	MOVL	AX, 0(SP)
	MOVL	$1, AX				/* return 1 */
	RET

TEXT setlabel(SB), $0
	MOVL	label+0(FP), AX
	MOVL	SP, 0(AX)			/* store sp */
	MOVL	0(SP), BX			/* store return pc */
	MOVL	BX, 4(AX)
	MOVL	$0, AX				/* return 0 */
	RET

/*
 * Interrupt/exception handling.
 * Each entry in the vector table calls either _strayintr or _strayintrx depending
 * on whether an error code has been automatically pushed onto the stack
 * (_strayintrx) or not, in which case a dummy entry must be pushed before retrieving
 * the trap type from the vector table entry and placing it on the stack as part
 * of the Ureg structure.
 * The size of each entry in the vector table (6 bytes) is known in trapinit().
 */
TEXT _strayintr(SB), $0
	PUSHL	AX			/* save AX */
	MOVL	4(SP), AX		/* return PC from vectortable(SB) */
	JMP	intrcommon

TEXT _strayintrx(SB), $0
	XCHGL	AX, (SP)		/* swap AX with vectortable CALL PC */
intrcommon:
	PUSHL	DS			/* save DS */
	PUSHL	$(KDSEL)
	POPL	DS			/* fix up DS */
	MOVBLZX	(AX), AX		/* trap type -> AX */
	XCHGL	AX, 4(SP)		/* exchange trap type with saved AX */

	PUSHL	ES			/* save ES */
	PUSHL	$(KDSEL)
	POPL	ES			/* fix up ES */

	PUSHL	FS			/* save the rest of the Ureg struct */
	PUSHL	GS
	PUSHAL

	PUSHL	SP			/* Ureg* argument to trap */
	CALL	trap(SB)

TEXT forkret(SB), $0
	POPL	AX
	POPAL
	POPL	GS
	POPL	FS
	POPL	ES
	POPL	DS
	ADDL	$8, SP				/* pop error code and trap type */
	IRETL

TEXT vectortable(SB), $0
	CALL _strayintr(SB); BYTE $0x00		/* divide error */
	CALL _strayintr(SB); BYTE $0x01		/* debug exception */
	CALL _strayintr(SB); BYTE $0x02		/* NMI interrupt */
	CALL _strayintr(SB); BYTE $0x03		/* breakpoint */
	CALL _strayintr(SB); BYTE $0x04		/* overflow */
	CALL _strayintr(SB); BYTE $0x05		/* bound */
	CALL _strayintr(SB); BYTE $0x06		/* invalid opcode */
	CALL _strayintr(SB); BYTE $0x07		/* no coprocessor available */
	CALL _strayintrx(SB); BYTE $0x08	/* double fault */
	CALL _strayintr(SB); BYTE $0x09		/* coprocessor segment overflow */
	CALL _strayintrx(SB); BYTE $0x0A	/* invalid TSS */
	CALL _strayintrx(SB); BYTE $0x0B	/* segment not available */
	CALL _strayintrx(SB); BYTE $0x0C	/* stack exception */
	CALL _strayintrx(SB); BYTE $0x0D	/* general protection error */
	CALL _strayintrx(SB); BYTE $0x0E	/* page fault */
	CALL _strayintr(SB); BYTE $0x0F		/*  */
	CALL _strayintr(SB); BYTE $0x10		/* coprocessor error */
	CALL _strayintrx(SB); BYTE $0x11	/* alignment check */
	CALL _strayintr(SB); BYTE $0x12		/* machine check */
	CALL _strayintr(SB); BYTE $0x13
	CALL _strayintr(SB); BYTE $0x14
	CALL _strayintr(SB); BYTE $0x15
	CALL _strayintr(SB); BYTE $0x16
	CALL _strayintr(SB); BYTE $0x17
	CALL _strayintr(SB); BYTE $0x18
	CALL _strayintr(SB); BYTE $0x19
	CALL _strayintr(SB); BYTE $0x1A
	CALL _strayintr(SB); BYTE $0x1B
	CALL _strayintr(SB); BYTE $0x1C
	CALL _strayintr(SB); BYTE $0x1D
	CALL _strayintr(SB); BYTE $0x1E
	CALL _strayintr(SB); BYTE $0x1F
	CALL _strayintr(SB); BYTE $0x20		/* VectorLAPIC */
	CALL _strayintr(SB); BYTE $0x21
	CALL _strayintr(SB); BYTE $0x22
	CALL _strayintr(SB); BYTE $0x23
	CALL _strayintr(SB); BYTE $0x24
	CALL _strayintr(SB); BYTE $0x25
	CALL _strayintr(SB); BYTE $0x26
	CALL _strayintr(SB); BYTE $0x27
	CALL _strayintr(SB); BYTE $0x28
	CALL _strayintr(SB); BYTE $0x29
	CALL _strayintr(SB); BYTE $0x2A
	CALL _strayintr(SB); BYTE $0x2B
	CALL _strayintr(SB); BYTE $0x2C
	CALL _strayintr(SB); BYTE $0x2D
	CALL _strayintr(SB); BYTE $0x2E
	CALL _strayintr(SB); BYTE $0x2F
	CALL _strayintr(SB); BYTE $0x30
	CALL _strayintr(SB); BYTE $0x31
	CALL _strayintr(SB); BYTE $0x32
	CALL _strayintr(SB); BYTE $0x33
	CALL _strayintr(SB); BYTE $0x34
	CALL _strayintr(SB); BYTE $0x35
	CALL _strayintr(SB); BYTE $0x36
	CALL _strayintr(SB); BYTE $0x37
	CALL _strayintr(SB); BYTE $0x38
	CALL _strayintr(SB); BYTE $0x39
	CALL _strayintr(SB); BYTE $0x3A
	CALL _strayintr(SB); BYTE $0x3B
	CALL _strayintr(SB); BYTE $0x3C
	CALL _strayintr(SB); BYTE $0x3D
	CALL _strayintr(SB); BYTE $0x3E
	CALL _strayintr(SB); BYTE $0x3F
	CALL _syscallintr(SB); BYTE $0x40	/* VectorSYSCALL */
	CALL _strayintr(SB); BYTE $0x41
	CALL _strayintr(SB); BYTE $0x42
	CALL _strayintr(SB); BYTE $0x43
	CALL _strayintr(SB); BYTE $0x44
	CALL _strayintr(SB); BYTE $0x45
	CALL _strayintr(SB); BYTE $0x46
	CALL _strayintr(SB); BYTE $0x47
	CALL _strayintr(SB); BYTE $0x48
	CALL _strayintr(SB); BYTE $0x49
	CALL _strayintr(SB); BYTE $0x4A
	CALL _strayintr(SB); BYTE $0x4B
	CALL _strayintr(SB); BYTE $0x4C
	CALL _strayintr(SB); BYTE $0x4D
	CALL _strayintr(SB); BYTE $0x4E
	CALL _strayintr(SB); BYTE $0x4F
	CALL _strayintr(SB); BYTE $0x50
	CALL _strayintr(SB); BYTE $0x51
	CALL _strayintr(SB); BYTE $0x52
	CALL _strayintr(SB); BYTE $0x53
	CALL _strayintr(SB); BYTE $0x54
	CALL _strayintr(SB); BYTE $0x55
	CALL _strayintr(SB); BYTE $0x56
	CALL _strayintr(SB); BYTE $0x57
	CALL _strayintr(SB); BYTE $0x58
	CALL _strayintr(SB); BYTE $0x59
	CALL _strayintr(SB); BYTE $0x5A
	CALL _strayintr(SB); BYTE $0x5B
	CALL _strayintr(SB); BYTE $0x5C
	CALL _strayintr(SB); BYTE $0x5D
	CALL _strayintr(SB); BYTE $0x5E
	CALL _strayintr(SB); BYTE $0x5F
	CALL _strayintr(SB); BYTE $0x60
	CALL _strayintr(SB); BYTE $0x61
	CALL _strayintr(SB); BYTE $0x62
	CALL _strayintr(SB); BYTE $0x63
	CALL _strayintr(SB); BYTE $0x64
	CALL _strayintr(SB); BYTE $0x65
	CALL _strayintr(SB); BYTE $0x66
	CALL _strayintr(SB); BYTE $0x67
	CALL _strayintr(SB); BYTE $0x68
	CALL _strayintr(SB); BYTE $0x69
	CALL _strayintr(SB); BYTE $0x6A
	CALL _strayintr(SB); BYTE $0x6B
	CALL _strayintr(SB); BYTE $0x6C
	CALL _strayintr(SB); BYTE $0x6D
	CALL _strayintr(SB); BYTE $0x6E
	CALL _strayintr(SB); BYTE $0x6F
	CALL _strayintr(SB); BYTE $0x70
	CALL _strayintr(SB); BYTE $0x71
	CALL _strayintr(SB); BYTE $0x72
	CALL _strayintr(SB); BYTE $0x73
	CALL _strayintr(SB); BYTE $0x74
	CALL _strayintr(SB); BYTE $0x75
	CALL _strayintr(SB); BYTE $0x76
	CALL _strayintr(SB); BYTE $0x77
	CALL _strayintr(SB); BYTE $0x78
	CALL _strayintr(SB); BYTE $0x79
	CALL _strayintr(SB); BYTE $0x7A
	CALL _strayintr(SB); BYTE $0x7B
	CALL _strayintr(SB); BYTE $0x7C
	CALL _strayintr(SB); BYTE $0x7D
	CALL _strayintr(SB); BYTE $0x7E
	CALL _strayintr(SB); BYTE $0x7F
	CALL _strayintr(SB); BYTE $0x80		/* Vector[A]PIC */
	CALL _strayintr(SB); BYTE $0x81
	CALL _strayintr(SB); BYTE $0x82
	CALL _strayintr(SB); BYTE $0x83
	CALL _strayintr(SB); BYTE $0x84
	CALL _strayintr(SB); BYTE $0x85
	CALL _strayintr(SB); BYTE $0x86
	CALL _strayintr(SB); BYTE $0x87
	CALL _strayintr(SB); BYTE $0x88
	CALL _strayintr(SB); BYTE $0x89
	CALL _strayintr(SB); BYTE $0x8A
	CALL _strayintr(SB); BYTE $0x8B
	CALL _strayintr(SB); BYTE $0x8C
	CALL _strayintr(SB); BYTE $0x8D
	CALL _strayintr(SB); BYTE $0x8E
	CALL _strayintr(SB); BYTE $0x8F
	CALL _strayintr(SB); BYTE $0x90
	CALL _strayintr(SB); BYTE $0x91
	CALL _strayintr(SB); BYTE $0x92
	CALL _strayintr(SB); BYTE $0x93
	CALL _strayintr(SB); BYTE $0x94
	CALL _strayintr(SB); BYTE $0x95
	CALL _strayintr(SB); BYTE $0x96
	CALL _strayintr(SB); BYTE $0x97
	CALL _strayintr(SB); BYTE $0x98
	CALL _strayintr(SB); BYTE $0x99
	CALL _strayintr(SB); BYTE $0x9A
	CALL _strayintr(SB); BYTE $0x9B
	CALL _strayintr(SB); BYTE $0x9C
	CALL _strayintr(SB); BYTE $0x9D
	CALL _strayintr(SB); BYTE $0x9E
	CALL _strayintr(SB); BYTE $0x9F
	CALL _strayintr(SB); BYTE $0xA0
	CALL _strayintr(SB); BYTE $0xA1
	CALL _strayintr(SB); BYTE $0xA2
	CALL _strayintr(SB); BYTE $0xA3
	CALL _strayintr(SB); BYTE $0xA4
	CALL _strayintr(SB); BYTE $0xA5
	CALL _strayintr(SB); BYTE $0xA6
	CALL _strayintr(SB); BYTE $0xA7
	CALL _strayintr(SB); BYTE $0xA8
	CALL _strayintr(SB); BYTE $0xA9
	CALL _strayintr(SB); BYTE $0xAA
	CALL _strayintr(SB); BYTE $0xAB
	CALL _strayintr(SB); BYTE $0xAC
	CALL _strayintr(SB); BYTE $0xAD
	CALL _strayintr(SB); BYTE $0xAE
	CALL _strayintr(SB); BYTE $0xAF
	CALL _strayintr(SB); BYTE $0xB0
	CALL _strayintr(SB); BYTE $0xB1
	CALL _strayintr(SB); BYTE $0xB2
	CALL _strayintr(SB); BYTE $0xB3
	CALL _strayintr(SB); BYTE $0xB4
	CALL _strayintr(SB); BYTE $0xB5
	CALL _strayintr(SB); BYTE $0xB6
	CALL _strayintr(SB); BYTE $0xB7
	CALL _strayintr(SB); BYTE $0xB8
	CALL _strayintr(SB); BYTE $0xB9
	CALL _strayintr(SB); BYTE $0xBA
	CALL _strayintr(SB); BYTE $0xBB
	CALL _strayintr(SB); BYTE $0xBC
	CALL _strayintr(SB); BYTE $0xBD
	CALL _strayintr(SB); BYTE $0xBE
	CALL _strayintr(SB); BYTE $0xBF
	CALL _strayintr(SB); BYTE $0xC0
	CALL _strayintr(SB); BYTE $0xC1
	CALL _strayintr(SB); BYTE $0xC2
	CALL _strayintr(SB); BYTE $0xC3
	CALL _strayintr(SB); BYTE $0xC4
	CALL _strayintr(SB); BYTE $0xC5
	CALL _strayintr(SB); BYTE $0xC6
	CALL _strayintr(SB); BYTE $0xC7
	CALL _strayintr(SB); BYTE $0xC8
	CALL _strayintr(SB); BYTE $0xC9
	CALL _strayintr(SB); BYTE $0xCA
	CALL _strayintr(SB); BYTE $0xCB
	CALL _strayintr(SB); BYTE $0xCC
	CALL _strayintr(SB); BYTE $0xCD
	CALL _strayintr(SB); BYTE $0xCE
	CALL _strayintr(SB); BYTE $0xCF
	CALL _strayintr(SB); BYTE $0xD0
	CALL _strayintr(SB); BYTE $0xD1
	CALL _strayintr(SB); BYTE $0xD2
	CALL _strayintr(SB); BYTE $0xD3
	CALL _strayintr(SB); BYTE $0xD4
	CALL _strayintr(SB); BYTE $0xD5
	CALL _strayintr(SB); BYTE $0xD6
	CALL _strayintr(SB); BYTE $0xD7
	CALL _strayintr(SB); BYTE $0xD8
	CALL _strayintr(SB); BYTE $0xD9
	CALL _strayintr(SB); BYTE $0xDA
	CALL _strayintr(SB); BYTE $0xDB
	CALL _strayintr(SB); BYTE $0xDC
	CALL _strayintr(SB); BYTE $0xDD
	CALL _strayintr(SB); BYTE $0xDE
	CALL _strayintr(SB); BYTE $0xDF
	CALL _strayintr(SB); BYTE $0xE0
	CALL _strayintr(SB); BYTE $0xE1
	CALL _strayintr(SB); BYTE $0xE2
	CALL _strayintr(SB); BYTE $0xE3
	CALL _strayintr(SB); BYTE $0xE4
	CALL _strayintr(SB); BYTE $0xE5
	CALL _strayintr(SB); BYTE $0xE6
	CALL _strayintr(SB); BYTE $0xE7
	CALL _strayintr(SB); BYTE $0xE8
	CALL _strayintr(SB); BYTE $0xE9
	CALL _strayintr(SB); BYTE $0xEA
	CALL _strayintr(SB); BYTE $0xEB
	CALL _strayintr(SB); BYTE $0xEC
	CALL _strayintr(SB); BYTE $0xED
	CALL _strayintr(SB); BYTE $0xEE
	CALL _strayintr(SB); BYTE $0xEF
	CALL _strayintr(SB); BYTE $0xF0
	CALL _strayintr(SB); BYTE $0xF1
	CALL _strayintr(SB); BYTE $0xF2
	CALL _strayintr(SB); BYTE $0xF3
	CALL _strayintr(SB); BYTE $0xF4
	CALL _strayintr(SB); BYTE $0xF5
	CALL _strayintr(SB); BYTE $0xF6
	CALL _strayintr(SB); BYTE $0xF7
	CALL _strayintr(SB); BYTE $0xF8
	CALL _strayintr(SB); BYTE $0xF9
	CALL _strayintr(SB); BYTE $0xFA
	CALL _strayintr(SB); BYTE $0xFB
	CALL _strayintr(SB); BYTE $0xFC
	CALL _strayintr(SB); BYTE $0xFD
	CALL _strayintr(SB); BYTE $0xFE
	CALL _strayintr(SB); BYTE $0xFF