projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| 3402aac7 | 1 | #------------------------------------------------------------------------------\r |
| 1e57a462 | 2 | #\r |
| 3 | # Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>\r | |
| 4 | #\r | |
| 4059386c | 5 | # SPDX-License-Identifier: BSD-2-Clause-Patent\r |
| 1e57a462 | 6 | #\r |
| 7 | #------------------------------------------------------------------------------\r | |
| 8 | \r | |
| 22b080c7 | 9 | #include <AsmMacroIoLib.h>\r |
| 1e57a462 | 10 | \r |
| 11 | /*\r | |
| 12 | Semihosting operation request mechanism\r | |
| 3402aac7 | 13 | \r |
| 1e57a462 | 14 | SVC 0x123456 in ARM state (for all architectures)\r |
| 15 | SVC 0xAB in Thumb state (excluding ARMv7-M)\r | |
| 16 | BKPT 0xAB for ARMv7-M (Thumb-2 only)\r | |
| 3402aac7 RC |
17 | \r |
| 18 | R0 - operation type\r | |
| 1e57a462 | 19 | R1 - block containing all other parametes\r |
| 3402aac7 RC |
20 | \r |
| 21 | lr - must be saved as svc instruction will cause an svc exception and write\r | |
| 1e57a462 | 22 | the svc lr register. That happens to be the one we are using, so we must\r |
| 3402aac7 | 23 | save it or we will not be able to return.\r |
| 1e57a462 | 24 | */\r |
| 22b080c7 | 25 | ASM_FUNC(GccSemihostCall)\r |
| 3402aac7 RC |
26 | stmfd sp!, {lr}\r |
| 27 | svc #0x123456\r | |
| 7d952405 | 28 | ldmfd sp!, {lr}\r |
| 1e57a462 | 29 | bx lr\r |
| 30 | \r | |
| 31 | \r |