github.com/icexin/eggos@v0.4.2-0.20220216025428-78b167e4f349/kernel/trap.s (about)

     1  #include "textflag.h"
     2  
     3  #define m_fpstate 32
     4  
     5  TEXT alltraps(SB), NOSPLIT, $0
     6  	PUSHQ R15
     7  	PUSHQ R14
     8  	PUSHQ R13
     9  	PUSHQ R12
    10  	PUSHQ R11
    11  	PUSHQ R10
    12  	PUSHQ R9
    13  	PUSHQ R8
    14  	PUSHQ DI
    15  	PUSHQ SI
    16  	PUSHQ BP
    17  	PUSHQ DX
    18  	PUSHQ CX
    19  	PUSHQ BX
    20  	PUSHQ AX
    21  
    22  	// CX store mythread
    23  	MOVQ   0(GS), CX
    24  	MOVQ   m_fpstate(CX), DX
    25  	FXSAVE (DX)
    26  
    27  	// make top stack frame
    28  	XORQ  BP, BP
    29  	PUSHQ SP
    30  	CALL  ·dotrap(SB)
    31  	ADDQ  $8, SP
    32  	JMP   ·trapret(SB)
    33  
    34  TEXT ·trapret(SB), NOSPLIT, $0
    35  	// CX store mythread
    36  	MOVQ 0(GS), CX
    37  
    38  	// restore FPU
    39  	MOVQ    m_fpstate(CX), DX
    40  	FXRSTOR (DX)
    41  
    42  	POPQ AX
    43  	POPQ BX
    44  	POPQ CX
    45  	POPQ DX
    46  	POPQ BP
    47  	POPQ SI
    48  	POPQ DI
    49  	POPQ R8
    50  	POPQ R9
    51  	POPQ R10
    52  	POPQ R11
    53  	POPQ R12
    54  	POPQ R13
    55  	POPQ R14
    56  	POPQ R15
    57  
    58  	ADDQ $16, SP // skip trapno and errcode
    59  
    60  	IRETQ
    61