github.com/AESNooper/go/src@v0.0.0-20220218095104-b56a4ab1bbbb/runtime/sys_windows_arm.s (about) 1 // Copyright 2018 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 #include "go_asm.h" 6 #include "go_tls.h" 7 #include "textflag.h" 8 #include "time_windows.h" 9 10 // Note: For system ABI, R0-R3 are args, R4-R11 are callee-save. 11 12 // void runtime·asmstdcall(void *c); 13 TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0 14 MOVM.DB.W [R4, R5, R14], (R13) // push {r4, r5, lr} 15 MOVW R0, R4 // put libcall * in r4 16 MOVW R13, R5 // save stack pointer in r5 17 18 // SetLastError(0) 19 MOVW $0, R0 20 MRC 15, 0, R1, C13, C0, 2 21 MOVW R0, 0x34(R1) 22 23 MOVW 8(R4), R12 // libcall->args 24 25 // Do we have more than 4 arguments? 26 MOVW 4(R4), R0 // libcall->n 27 SUB.S $4, R0, R2 28 BLE loadregs 29 30 // Reserve stack space for remaining args 31 SUB R2<<2, R13 32 BIC $0x7, R13 // alignment for ABI 33 34 // R0: count of arguments 35 // R1: 36 // R2: loop counter, from 0 to (n-4) 37 // R3: scratch 38 // R4: pointer to libcall struct 39 // R12: libcall->args 40 MOVW $0, R2 41 stackargs: 42 ADD $4, R2, R3 // r3 = args[4 + i] 43 MOVW R3<<2(R12), R3 44 MOVW R3, R2<<2(R13) // stack[i] = r3 45 46 ADD $1, R2 // i++ 47 SUB $4, R0, R3 // while (i < (n - 4)) 48 CMP R3, R2 49 BLT stackargs 50 51 loadregs: 52 CMP $3, R0 53 MOVW.GT 12(R12), R3 54 55 CMP $2, R0 56 MOVW.GT 8(R12), R2 57 58 CMP $1, R0 59 MOVW.GT 4(R12), R1 60 61 CMP $0, R0 62 MOVW.GT 0(R12), R0 63 64 BIC $0x7, R13 // alignment for ABI 65 MOVW 0(R4), R12 // branch to libcall->fn 66 BL (R12) 67 68 MOVW R5, R13 // free stack space 69 MOVW R0, 12(R4) // save return value to libcall->r1 70 MOVW R1, 16(R4) 71 72 // GetLastError 73 MRC 15, 0, R1, C13, C0, 2 74 MOVW 0x34(R1), R0 75 MOVW R0, 20(R4) // store in libcall->err 76 77 MOVM.IA.W (R13), [R4, R5, R15] 78 79 TEXT runtime·badsignal2(SB),NOSPLIT|NOFRAME,$0 80 MOVM.DB.W [R4, R14], (R13) // push {r4, lr} 81 MOVW R13, R4 // save original stack pointer 82 SUB $8, R13 // space for 2 variables 83 BIC $0x7, R13 // alignment for ABI 84 85 // stderr 86 MOVW runtime·_GetStdHandle(SB), R1 87 MOVW $-12, R0 88 BL (R1) 89 90 MOVW $runtime·badsignalmsg(SB), R1 // lpBuffer 91 MOVW $runtime·badsignallen(SB), R2 // lpNumberOfBytesToWrite 92 MOVW (R2), R2 93 ADD $0x4, R13, R3 // lpNumberOfBytesWritten 94 MOVW $0, R12 // lpOverlapped 95 MOVW R12, (R13) 96 97 MOVW runtime·_WriteFile(SB), R12 98 BL (R12) 99 100 // Does not return. 101 B runtime·abort(SB) 102 103 TEXT runtime·getlasterror(SB),NOSPLIT,$0 104 MRC 15, 0, R0, C13, C0, 2 105 MOVW 0x34(R0), R0 106 MOVW R0, ret+0(FP) 107 RET 108 109 // Called by Windows as a Vectored Exception Handler (VEH). 110 // First argument is pointer to struct containing 111 // exception record and context pointers. 112 // Handler function is stored in R1 113 // Return 0 for 'not handled', -1 for handled. 114 // int32_t sigtramp( 115 // PEXCEPTION_POINTERS ExceptionInfo, 116 // func *GoExceptionHandler); 117 TEXT sigtramp<>(SB),NOSPLIT|NOFRAME,$0 118 MOVM.DB.W [R0, R4-R11, R14], (R13) // push {r0, r4-r11, lr} (SP-=40) 119 SUB $(8+20), R13 // reserve space for g, sp, and 120 // parameters/retval to go call 121 122 MOVW R0, R6 // Save param0 123 MOVW R1, R7 // Save param1 124 125 BL runtime·load_g(SB) 126 CMP $0, g // is there a current g? 127 BL.EQ runtime·badsignal2(SB) 128 129 // save g and SP in case of stack switch 130 MOVW R13, 24(R13) 131 MOVW g, 20(R13) 132 133 // do we need to switch to the g0 stack? 134 MOVW g, R5 // R5 = g 135 MOVW g_m(R5), R2 // R2 = m 136 MOVW m_g0(R2), R4 // R4 = g0 137 CMP R5, R4 // if curg == g0 138 BEQ g0 139 140 // switch to g0 stack 141 MOVW R4, g // g = g0 142 MOVW (g_sched+gobuf_sp)(g), R3 // R3 = g->gobuf.sp 143 BL runtime·save_g(SB) 144 145 // make room for sighandler arguments 146 // and re-save old SP for restoring later. 147 // (note that the 24(R3) here must match the 24(R13) above.) 148 SUB $40, R3 149 MOVW R13, 24(R3) // save old stack pointer 150 MOVW R3, R13 // switch stack 151 152 g0: 153 MOVW 0(R6), R2 // R2 = ExceptionPointers->ExceptionRecord 154 MOVW 4(R6), R3 // R3 = ExceptionPointers->ContextRecord 155 156 MOVW $0, R4 157 MOVW R4, 0(R13) // No saved link register. 158 MOVW R2, 4(R13) // Move arg0 (ExceptionRecord) into position 159 MOVW R3, 8(R13) // Move arg1 (ContextRecord) into position 160 MOVW R5, 12(R13) // Move arg2 (original g) into position 161 BL (R7) // Call the goroutine 162 MOVW 16(R13), R4 // Fetch return value from stack 163 164 // Save system stack pointer for sigresume setup below. 165 // The exact value does not matter - nothing is read or written 166 // from this address. It just needs to be on the system stack. 167 MOVW R13, R12 168 169 // switch back to original stack and g 170 MOVW 24(R13), R13 171 MOVW 20(R13), g 172 BL runtime·save_g(SB) 173 174 done: 175 MOVW R4, R0 // move retval into position 176 ADD $(8 + 20), R13 // free locals 177 MOVM.IA.W (R13), [R3, R4-R11, R14] // pop {r3, r4-r11, lr} 178 179 // if return value is CONTINUE_SEARCH, do not set up control 180 // flow guard workaround 181 CMP $0, R0 182 BEQ return 183 184 // Check if we need to set up the control flow guard workaround. 185 // On Windows, the stack pointer in the context must lie within 186 // system stack limits when we resume from exception. 187 // Store the resume SP and PC on the g0 stack, 188 // and return to sigresume on the g0 stack. sigresume 189 // pops the saved PC and SP from the g0 stack, resuming execution 190 // at the desired location. 191 // If sigresume has already been set up by a previous exception 192 // handler, don't clobber the stored SP and PC on the stack. 193 MOVW 4(R3), R3 // PEXCEPTION_POINTERS->Context 194 MOVW context_pc(R3), R2 // load PC from context record 195 MOVW $sigresume<>(SB), R1 196 CMP R1, R2 197 B.EQ return // do not clobber saved SP/PC 198 199 // Save resume SP and PC into R0, R1. 200 MOVW context_spr(R3), R2 201 MOVW R2, context_r0(R3) 202 MOVW context_pc(R3), R2 203 MOVW R2, context_r1(R3) 204 205 // Set up context record to return to sigresume on g0 stack 206 MOVW R12, context_spr(R3) 207 MOVW $sigresume<>(SB), R2 208 MOVW R2, context_pc(R3) 209 210 return: 211 B (R14) // return 212 213 // Trampoline to resume execution from exception handler. 214 // This is part of the control flow guard workaround. 215 // It switches stacks and jumps to the continuation address. 216 // R0 and R1 are set above at the end of sigtramp<> 217 // in the context that starts executing at sigresume<>. 218 TEXT sigresume<>(SB),NOSPLIT|NOFRAME,$0 219 // Important: do not smash LR, 220 // which is set to a live value when handling 221 // a signal by pushing a call to sigpanic onto the stack. 222 MOVW R0, R13 223 B (R1) 224 225 TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0 226 MOVW $runtime·exceptionhandler(SB), R1 227 B sigtramp<>(SB) 228 229 TEXT runtime·firstcontinuetramp(SB),NOSPLIT|NOFRAME,$0 230 MOVW $runtime·firstcontinuehandler(SB), R1 231 B sigtramp<>(SB) 232 233 TEXT runtime·lastcontinuetramp(SB),NOSPLIT|NOFRAME,$0 234 MOVW $runtime·lastcontinuehandler(SB), R1 235 B sigtramp<>(SB) 236 237 GLOBL runtime·cbctxts(SB), NOPTR, $4 238 239 TEXT runtime·callbackasm1(SB),NOSPLIT|NOFRAME,$0 240 // On entry, the trampoline in zcallback_windows_arm.s left 241 // the callback index in R12 (which is volatile in the C ABI). 242 243 // Push callback register arguments r0-r3. We do this first so 244 // they're contiguous with stack arguments. 245 MOVM.DB.W [R0-R3], (R13) 246 // Push C callee-save registers r4-r11 and lr. 247 MOVM.DB.W [R4-R11, R14], (R13) 248 SUB $(16 + callbackArgs__size), R13 // space for locals 249 250 // Create a struct callbackArgs on our stack. 251 MOVW R12, (16+callbackArgs_index)(R13) // callback index 252 MOVW $(16+callbackArgs__size+4*9)(R13), R0 253 MOVW R0, (16+callbackArgs_args)(R13) // address of args vector 254 MOVW $0, R0 255 MOVW R0, (16+callbackArgs_result)(R13) // result 256 257 // Prepare for entry to Go. 258 BL runtime·load_g(SB) 259 260 // Call cgocallback, which will call callbackWrap(frame). 261 MOVW $0, R0 262 MOVW R0, 12(R13) // context 263 MOVW $16(R13), R1 // R1 = &callbackArgs{...} 264 MOVW R1, 8(R13) // frame (address of callbackArgs) 265 MOVW $·callbackWrap(SB), R1 266 MOVW R1, 4(R13) // PC of function to call 267 BL runtime·cgocallback(SB) 268 269 // Get callback result. 270 MOVW (16+callbackArgs_result)(R13), R0 271 272 ADD $(16 + callbackArgs__size), R13 // free locals 273 MOVM.IA.W (R13), [R4-R11, R12] // pop {r4-r11, lr=>r12} 274 ADD $(4*4), R13 // skip r0-r3 275 B (R12) // return 276 277 // uint32 tstart_stdcall(M *newm); 278 TEXT runtime·tstart_stdcall(SB),NOSPLIT|NOFRAME,$0 279 MOVM.DB.W [R4-R11, R14], (R13) // push {r4-r11, lr} 280 281 MOVW m_g0(R0), g 282 MOVW R0, g_m(g) 283 BL runtime·save_g(SB) 284 285 // Layout new m scheduler stack on os stack. 286 MOVW R13, R0 287 MOVW R0, g_stack+stack_hi(g) 288 SUB $(64*1024), R0 289 MOVW R0, (g_stack+stack_lo)(g) 290 MOVW R0, g_stackguard0(g) 291 MOVW R0, g_stackguard1(g) 292 293 BL runtime·emptyfunc(SB) // fault if stack check is wrong 294 BL runtime·mstart(SB) 295 296 // Exit the thread. 297 MOVW $0, R0 298 MOVM.IA.W (R13), [R4-R11, R15] // pop {r4-r11, pc} 299 300 // Runs on OS stack. 301 // duration (in -100ns units) is in dt+0(FP). 302 // g may be nil. 303 TEXT runtime·usleep2(SB),NOSPLIT|NOFRAME,$0-4 304 MOVW dt+0(FP), R3 305 MOVM.DB.W [R4, R14], (R13) // push {r4, lr} 306 MOVW R13, R4 // Save SP 307 SUB $8, R13 // R13 = R13 - 8 308 BIC $0x7, R13 // Align SP for ABI 309 MOVW $0, R1 // R1 = FALSE (alertable) 310 MOVW $-1, R0 // R0 = handle 311 MOVW R13, R2 // R2 = pTime 312 MOVW R3, 0(R2) // time_lo 313 MOVW R0, 4(R2) // time_hi 314 MOVW runtime·_NtWaitForSingleObject(SB), R3 315 BL (R3) 316 MOVW R4, R13 // Restore SP 317 MOVM.IA.W (R13), [R4, R15] // pop {R4, pc} 318 319 // Runs on OS stack. 320 // duration (in -100ns units) is in dt+0(FP). 321 // g is valid. 322 // TODO: neeeds to be implemented properly. 323 TEXT runtime·usleep2HighRes(SB),NOSPLIT|NOFRAME,$0-4 324 B runtime·abort(SB) 325 326 // Runs on OS stack. 327 TEXT runtime·switchtothread(SB),NOSPLIT|NOFRAME,$0 328 MOVM.DB.W [R4, R14], (R13) // push {R4, lr} 329 MOVW R13, R4 330 BIC $0x7, R13 // alignment for ABI 331 MOVW runtime·_SwitchToThread(SB), R0 332 BL (R0) 333 MOVW R4, R13 // restore stack pointer 334 MOVM.IA.W (R13), [R4, R15] // pop {R4, pc} 335 336 TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0 337 B runtime·armPublicationBarrier(SB) 338 339 // never called (this is a GOARM=7 platform) 340 TEXT runtime·read_tls_fallback(SB),NOSPLIT|NOFRAME,$0 341 MOVW $0xabcd, R0 342 MOVW R0, (R0) 343 RET 344 345 TEXT runtime·nanotime1(SB),NOSPLIT|NOFRAME,$0-8 346 MOVW $0, R0 347 MOVB runtime·useQPCTime(SB), R0 348 CMP $0, R0 349 BNE useQPC 350 MOVW $_INTERRUPT_TIME, R3 351 loop: 352 MOVW time_hi1(R3), R1 353 DMB MB_ISH 354 MOVW time_lo(R3), R0 355 DMB MB_ISH 356 MOVW time_hi2(R3), R2 357 CMP R1, R2 358 BNE loop 359 360 // wintime = R1:R0, multiply by 100 361 MOVW $100, R2 362 MULLU R0, R2, (R4, R3) // R4:R3 = R1:R0 * R2 363 MULA R1, R2, R4, R4 364 365 // wintime*100 = R4:R3 366 MOVW R3, ret_lo+0(FP) 367 MOVW R4, ret_hi+4(FP) 368 RET 369 useQPC: 370 B runtime·nanotimeQPC(SB) // tail call 371 372 // save_g saves the g register (R10) into thread local memory 373 // so that we can call externally compiled 374 // ARM code that will overwrite those registers. 375 // NOTE: runtime.gogo assumes that R1 is preserved by this function. 376 // runtime.mcall assumes this function only clobbers R0 and R11. 377 // Returns with g in R0. 378 // Save the value in the _TEB->TlsSlots array. 379 // Effectively implements TlsSetValue(). 380 // tls_g stores the TLS slot allocated TlsAlloc(). 381 TEXT runtime·save_g(SB),NOSPLIT|NOFRAME,$0 382 MRC 15, 0, R0, C13, C0, 2 383 ADD $0xe10, R0 384 MOVW $runtime·tls_g(SB), R11 385 MOVW (R11), R11 386 MOVW g, R11<<2(R0) 387 MOVW g, R0 // preserve R0 across call to setg<> 388 RET 389 390 // load_g loads the g register from thread-local memory, 391 // for use after calling externally compiled 392 // ARM code that overwrote those registers. 393 // Get the value from the _TEB->TlsSlots array. 394 // Effectively implements TlsGetValue(). 395 TEXT runtime·load_g(SB),NOSPLIT|NOFRAME,$0 396 MRC 15, 0, R0, C13, C0, 2 397 ADD $0xe10, R0 398 MOVW $runtime·tls_g(SB), g 399 MOVW (g), g 400 MOVW g<<2(R0), g 401 RET 402 403 // This is called from rt0_go, which runs on the system stack 404 // using the initial stack allocated by the OS. 405 // It calls back into standard C using the BL below. 406 // To do that, the stack pointer must be 8-byte-aligned. 407 TEXT runtime·_initcgo(SB),NOSPLIT|NOFRAME,$0 408 MOVM.DB.W [R4, R14], (R13) // push {r4, lr} 409 410 // Ensure stack is 8-byte aligned before calling C code 411 MOVW R13, R4 412 BIC $0x7, R13 413 414 // Allocate a TLS slot to hold g across calls to external code 415 MOVW $runtime·_TlsAlloc(SB), R0 416 MOVW (R0), R0 417 BL (R0) 418 419 // Assert that slot is less than 64 so we can use _TEB->TlsSlots 420 CMP $64, R0 421 MOVW $runtime·abort(SB), R1 422 BL.GE (R1) 423 424 // Save Slot into tls_g 425 MOVW $runtime·tls_g(SB), R1 426 MOVW R0, (R1) 427 428 MOVW R4, R13 429 MOVM.IA.W (R13), [R4, R15] // pop {r4, pc} 430 431 // Holds the TLS Slot, which was allocated by TlsAlloc() 432 GLOBL runtime·tls_g+0(SB), NOPTR, $4