1 #------------------------------------------------------------------------------ 2 # 3 # Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR> 4 # 5 # This program and the accompanying materials 6 # are licensed and made available under the terms and conditions of the BSD License 7 # which accompanies this distribution. The full text of the license may be found at 8 # http://opensource.org/licenses/bsd-license.php 9 # 10 # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 11 # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 12 # 13 #------------------------------------------------------------------------------ 14 15 .text 16 .align 2 17 18 .globl ASM_PFX(GccSemihostCall) 19 INTERWORK_FUNC(GccSemihostCall) 20 21 /* 22 Semihosting operation request mechanism 23 24 SVC 0x123456 in ARM state (for all architectures) 25 SVC 0xAB in Thumb state (excluding ARMv7-M) 26 BKPT 0xAB for ARMv7-M (Thumb-2 only) 27 28 R0 - operation type 29 R1 - block containing all other parametes 30 31 lr - must be saved as svc instruction will cause an svc exception and write 32 the svc lr register. That happens to be the one we are using, so we must 33 save it or we will not be able to return. 34 */ 35 ASM_PFX(GccSemihostCall): 36 stmfd sp!, {lr} 37 svc #0x123456 38 ldmfd sp!, {lr} 39 bx lr 40 41 42