The adb commands to modify segments of the virtual address map and object file map are not present in MDB. Specifically, the /m, /*m, ?m, and ?*m format specifiers are not recognized or supported by MDB. These specifiers were used to manually modify the valid addressable range of the current object and core files. MDB properly recognizes the addressable range of such files automatically, and updates the ranges when a live process is being debugged, so these commands are no longer necessary.