Источник информации:
http://rod.info/arm.html--кусь--
One thing that is not documented very well when using Insight/GDB with the Macraigor tools is setting hardware breakpoints (which are required for debugging firmware running out of Flash). Insight/GDB is not able to directly set the hardware breakpoints, however with the 'monitor' command you can get access to the low-level registers and extra commands that Insight/GDB do not (currently) support.
For example to set a hardware break point at 0x12345678 type in the following in the Insight/GDB console:
monitor set hbreak 0x12345678
--кусь--
Сам так не делал. Только из ОЗУ. Т.к. шить ПЗУ лень каждый раз.