This is the B2 version of the RP2040 bootrom.

The version on the chip was built in Debug mode using GCC 9.3.1 (GNU Arm Embedded Toolchain 9-2020-q2-update).

Note the GIT revision info (included in the bootrom) on chip does not match the GIT revision of this branch. Additionally, certain DMB instructions are encoded as DMB SY vs DMB ISH when building with current SDKs although this has no functional effect on the RP2040.