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Editing: sys_windows_arm.s
// Copyright 2018 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. #include "go_asm.h" #include "go_tls.h" #include "textflag.h" #include "time_windows.h" // Note: For system ABI, R0-R3 are args, R4-R11 are callee-save. TEXT runtime·asmstdcall_trampoline<ABIInternal>(SB),NOSPLIT,$0 B runtime·asmstdcall(SB) // void runtime·asmstdcall(void *c); TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0 MOVM.DB.W [R4, R5, R14], (R13) // push {r4, r5, lr} MOVW R0, R4 // put libcall * in r4 MOVW R13, R5 // save stack pointer in r5 // SetLastError(0) MOVW $0, R0 MRC 15, 0, R1, C13, C0, 2 MOVW R0, 0x34(R1) MOVW 8(R4), R12 // libcall->args // Do we have more than 4 arguments? MOVW 4(R4), R0 // libcall->n SUB.S $4, R0, R2 BLE loadregs // Reserve stack space for remaining args SUB R2<<2, R13 BIC $0x7, R13 // alignment for ABI // R0: count of arguments // R1: // R2: loop counter, from 0 to (n-4) // R3: scratch // R4: pointer to libcall struct // R12: libcall->args MOVW $0, R2 stackargs: ADD $4, R2, R3 // r3 = args[4 + i] MOVW R3<<2(R12), R3 MOVW R3, R2<<2(R13) // stack[i] = r3 ADD $1, R2 // i++ SUB $4, R0, R3 // while (i < (n - 4)) CMP R3, R2 BLT stackargs loadregs: CMP $3, R0 MOVW.GT 12(R12), R3 CMP $2, R0 MOVW.GT 8(R12), R2 CMP $1, R0 MOVW.GT 4(R12), R1 CMP $0, R0 MOVW.GT 0(R12), R0 BIC $0x7, R13 // alignment for ABI MOVW 0(R4), R12 // branch to libcall->fn BL (R12) MOVW R5, R13 // free stack space MOVW R0, 12(R4) // save return value to libcall->r1 MOVW R1, 16(R4) // GetLastError MRC 15, 0, R1, C13, C0, 2 MOVW 0x34(R1), R0 MOVW R0, 20(R4) // store in libcall->err MOVM.IA.W (R13), [R4, R5, R15] TEXT runtime·getlasterror(SB),NOSPLIT,$0 MRC 15, 0, R0, C13, C0, 2 MOVW 0x34(R0), R0 MOVW R0, ret+0(FP) RET // Called by Windows as a Vectored Exception Handler (VEH). // R0 is pointer to struct containing // exception record and context pointers. // R1 is the kind of sigtramp function. // Return value of sigtrampgo is stored in R0. TEXT sigtramp<>(SB),NOSPLIT|NOFRAME,$0 MOVM.DB.W [R4-R11, R14], (R13) // push {r4-r11, lr} (SP-=40) SUB $(16), R13 // reserve space for parameters/retval to go call MOVW R0, R6 // Save param0 MOVW R1, R7 // Save param1 BL runtime·load_g(SB) // Clobbers R0 MOVW $0, R4 MOVW R4, 0(R13) // No saved link register. MOVW R6, 4(R13) // Move arg0 into position MOVW R7, 8(R13) // Move arg1 into position BL runtime·sigtrampgo(SB) MOVW 12(R13), R0 // Fetch return value from stack ADD $(16), R13 // free locals MOVM.IA.W (R13), [R4-R11, R14] // pop {r4-r11, lr} B (R14) // return // Trampoline to resume execution from exception handler. // This is part of the control flow guard workaround. // It switches stacks and jumps to the continuation address. // R0 and R1 are set above at the end of sigtrampgo // in the context that starts executing at sigresume. TEXT runtime·sigresume(SB),NOSPLIT|NOFRAME,$0 // Important: do not smash LR, // which is set to a live value when handling // a signal by pushing a call to sigpanic onto the stack. MOVW R0, R13 B (R1) TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0 MOVW $const_callbackVEH, R1 B sigtramp<>(SB) TEXT runtime·firstcontinuetramp(SB),NOSPLIT|NOFRAME,$0 MOVW $const_callbackFirstVCH, R1 B sigtramp<>(SB) TEXT runtime·lastcontinuetramp(SB),NOSPLIT|NOFRAME,$0 MOVW $const_callbackLastVCH, R1 B sigtramp<>(SB) TEXT runtime·callbackasm1(SB),NOSPLIT|NOFRAME,$0 // On entry, the trampoline in zcallback_windows_arm.s left // the callback index in R12 (which is volatile in the C ABI). // Push callback register arguments r0-r3. We do this first so // they're contiguous with stack arguments. MOVM.DB.W [R0-R3], (R13) // Push C callee-save registers r4-r11 and lr. MOVM.DB.W [R4-R11, R14], (R13) SUB $(16 + callbackArgs__size), R13 // space for locals // Create a struct callbackArgs on our stack. MOVW R12, (16+callbackArgs_index)(R13) // callback index MOVW $(16+callbackArgs__size+4*9)(R13), R0 MOVW R0, (16+callbackArgs_args)(R13) // address of args vector MOVW $0, R0 MOVW R0, (16+callbackArgs_result)(R13) // result // Prepare for entry to Go. BL runtime·load_g(SB) // Call cgocallback, which will call callbackWrap(frame). MOVW $0, R0 MOVW R0, 12(R13) // context MOVW $16(R13), R1 // R1 = &callbackArgs{...} MOVW R1, 8(R13) // frame (address of callbackArgs) MOVW $·callbackWrap(SB), R1 MOVW R1, 4(R13) // PC of function to call BL runtime·cgocallback(SB) // Get callback result. MOVW (16+callbackArgs_result)(R13), R0 ADD $(16 + callbackArgs__size), R13 // free locals MOVM.IA.W (R13), [R4-R11, R12] // pop {r4-r11, lr=>r12} ADD $(4*4), R13 // skip r0-r3 B (R12) // return // uint32 tstart_stdcall(M *newm); TEXT runtime·tstart_stdcall(SB),NOSPLIT|NOFRAME,$0 MOVM.DB.W [R4-R11, R14], (R13) // push {r4-r11, lr} MOVW m_g0(R0), g MOVW R0, g_m(g) BL runtime·save_g(SB) // Layout new m scheduler stack on os stack. MOVW R13, R0 MOVW R0, g_stack+stack_hi(g) SUB $(64*1024), R0 MOVW R0, (g_stack+stack_lo)(g) MOVW R0, g_stackguard0(g) MOVW R0, g_stackguard1(g) BL runtime·emptyfunc(SB) // fault if stack check is wrong BL runtime·mstart(SB) // Exit the thread. MOVW $0, R0 MOVM.IA.W (R13), [R4-R11, R15] // pop {r4-r11, pc} TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0 B runtime·armPublicationBarrier(SB) // never called (this is a GOARM=7 platform) TEXT runtime·read_tls_fallback(SB),NOSPLIT,$0 MOVW $0xabcd, R0 MOVW R0, (R0) RET TEXT runtime·nanotime1(SB),NOSPLIT,$0-8 loop: MOVW time_hi1(R3), R1 DMB MB_ISH MOVW time_lo(R3), R0 DMB MB_ISH MOVW time_hi2(R3), R2 CMP R1, R2 BNE loop // wintime = R1:R0, multiply by 100 MOVW $100, R2 MULLU R0, R2, (R4, R3) // R4:R3 = R1:R0 * R2 MULA R1, R2, R4, R4 // wintime*100 = R4:R3 MOVW R3, ret_lo+0(FP) MOVW R4, ret_hi+4(FP) RET // save_g saves the g register (R10) into thread local memory // so that we can call externally compiled // ARM code that will overwrite those registers. // NOTE: runtime.gogo assumes that R1 is preserved by this function. // runtime.mcall assumes this function only clobbers R0 and R11. // Returns with g in R0. // Save the value in the _TEB->TlsSlots array. // Effectively implements TlsSetValue(). // tls_g stores the TLS slot allocated TlsAlloc(). TEXT runtime·save_g(SB),NOSPLIT,$0 MRC 15, 0, R0, C13, C0, 2 ADD $0xe10, R0 MOVW $runtime·tls_g(SB), R11 MOVW (R11), R11 MOVW g, R11<<2(R0) MOVW g, R0 // preserve R0 across call to setg<> RET // load_g loads the g register from thread-local memory, // for use after calling externally compiled // ARM code that overwrote those registers. // Get the value from the _TEB->TlsSlots array. // Effectively implements TlsGetValue(). TEXT runtime·load_g(SB),NOSPLIT,$0 MRC 15, 0, R0, C13, C0, 2 ADD $0xe10, R0 MOVW $runtime·tls_g(SB), g MOVW (g), g MOVW g<<2(R0), g RET // This is called from rt0_go, which runs on the system stack // using the initial stack allocated by the OS. // It calls back into standard C using the BL below. // To do that, the stack pointer must be 8-byte-aligned. TEXT runtime·_initcgo(SB),NOSPLIT|NOFRAME,$0 MOVM.DB.W [R4, R14], (R13) // push {r4, lr} // Ensure stack is 8-byte aligned before calling C code MOVW R13, R4 BIC $0x7, R13 // Allocate a TLS slot to hold g across calls to external code MOVW $runtime·_TlsAlloc(SB), R0 MOVW (R0), R0 BL (R0) // Assert that slot is less than 64 so we can use _TEB->TlsSlots CMP $64, R0 MOVW $runtime·abort(SB), R1 BL.GE (R1) // Save Slot into tls_g MOVW $runtime·tls_g(SB), R1 MOVW R0, (R1) MOVW R4, R13 MOVM.IA.W (R13), [R4, R15] // pop {r4, pc} // Holds the TLS Slot, which was allocated by TlsAlloc() GLOBL runtime·tls_g+0(SB), NOPTR, $4
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