Reproduced from infocenter.arm.com: | Name | Maps To | Meaning | | ---- | ------- | ------- | | r0-r15 | r0-r15 | These are the the registers! | | a1-a4 | r0-r3 | Argument, result, or scratch registers | | v1-v8 | r4-r11 | Variable registers | | sb | r9 | Static base register | | fp | r11 | Frame pointer* | | ip | r12 | Intra-procedure call register | | sp | r13 | Stack pointer | | lr | r14 | link register | | pc | r15 | program counter |
* fp does not appear to be explicitly referenced in ARM documentation, and mapping to r11 looks to be OS (Windows/Linux?) convention.