When Zalasr is enabled, it will emit the A7 atomic ABI tag. Zalasr is the load-acquire and store-release extension, and the reason A7 (and A6S) exists is to support it. The A7 atomic ABI is compatible with A6S (which is what is currently emitted as the tag), but A7 is not compatible with A6C, while A6C and A6S are compatible. https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-atomic.adoc#risc-v-atomics-mappings https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc#tag_riscv_atomic_abi-14-uleb128version