85
edits
Changes
Jump to navigation
Jump to search
Line 45:
Line 45: − +
→Authenticated Mode Entry/Exit
=== Authenticated Mode Entry/Exit ===
=== Authenticated Mode Entry/Exit ===
Entry to Authenticated Mode always sets $pc to the address supplied in $cauth (ie the base of the signature-checked region). This takes effect when trying to branch to any address within the range covered by $cauth.
Entry to Authenticated Mode always sets $pc to the address supplied in $cauth (ie the base of the signature-checked region). This takes effect when trying to branch to any address within the range covered by $cauth. Entry to Authenticated Mode (also called "Secure Mode") computes a MAC over the $cauth region and compares it to $c6 in order to perform the signature check.
Exit from Authenticated Mode must poke a special register (this seems to be I[0x10300] = 0) before leaving authenticated code pages. Failure to do this would result in the Falcon core halting.
Exit from Authenticated Mode must poke a special register (this seems to be I[0x10300] = 0) before leaving authenticated code pages. Failure to do this would result in the Falcon core halting.