1 // Copyright 2020 The Pigweed Authors
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
7 // https://www.apache.org/licenses/LICENSE-2.0
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
18 namespace pw::interrupt {
20 #if defined(PW_INTERRUPT_CORTEX_M_ARMV7M) || \
21 defined(PW_INTERRUPT_CORTEX_M_ARMV8M)
22 inline bool InInterruptContext() {
23 // ARMv7M Reference manual section B1.4.2 describes how the Interrupt
24 // Program Status Register (IPSR) is zero if there is no exception (interrupt)
27 asm volatile("MRS %0, ipsr" : "=r"(ipsr));
31 #error "Please select an architecture specific backend."
34 } // namespace pw::interrupt