| // | |
| // Copyright (c) 2016 - 2020, ARM Limited. All rights reserved. | |
| // | |
| // SPDX-License-Identifier: BSD-2-Clause-Patent | |
| // | |
| // | |
| .text | |
| .align 3 | |
| GCC_ASM_EXPORT(ArmCallSvc) | |
| ASM_PFX(ArmCallSvc): | |
| // r0 will be popped just after the SVC call | |
| push {r0, r4-r8} | |
| // Load the SVC arguments values into the appropriate registers | |
| ldm r0, {r0-r7} | |
| svc #0 | |
| // Prevent speculative execution beyond svc instruction | |
| dsb nsh | |
| isb | |
| // Load the ARM_SVC_ARGS structure address from the stack into r8 | |
| ldr r8, [sp] | |
| // Load the SVC returned values into the appropriate registers | |
| // A SVC call can return up to 4 values - we do not need to store back r4-r7. | |
| stm r8, {r0-r3} | |
| mov r0, r8 | |
| // Restore the registers r4-r8 | |
| pop {r1, r4-r8} | |
| bx lr |