#258 BSLSKEY section support
Several mcu's (for example, msp430f235) designate the word immediately below the interrupt vector (0xffde) as used for a BSL security key. Depending on what value is stored here, the BSL behavior differs (either disabling BSL entry, or preventing mass erase on reception of an invalid BSL password). This address is not currently mapped to any section in the provided linker scripts. I don't know if there are other currently-unmapped addresses that have such uses.
This discussion contains a description of how I resolved the problem for my use case: https://sourceforge.net/mailarchive/message.php?msg_id=28604760
Since BSLSKEY is not present in all devices, it probably shouldn't be in the msp430.x linker script shared by all devices. I'm not very familar with ld scripts. If it's possible to do so, it would probably be sufficient to have an INCLUDE statement in the SECTIONS block that includes an mcu-specific script (containing extensions for any non-standard sections that need to be mapped).
(accidentally added, not sure how to remove)
Assigning to Rosty to get necessary information into msp430mcu; once it's available there BSLSKEY support can be added to the toolchain.