nova/core/falcon.rst

6 The following sections describe the Falcon core and the ucode running on it.
18 The code running on the Falcon cores is also called 'ucode', and will be
33 HS ucode is the most trusted code and has access to pretty much everything on
38 (Write Protect Region), has to be done by the HS ucode and cannot be done by the
39 host CPU or LS ucode.
43 These modes are less secure than HS. Like HS, the LS or NS ucode binary also
47 ucode in HS mode on the SEC2 Falcon, which then authenticates and runs the
60 After nova-core driver reads the necessary ucode from VBIOS, it programs the
61 BROM and DMA registers to trigger the Falcon to load the HS ucode from the system
62 memory into the Falcon's IMEM/DMEM. Once the HS ucode is loaded, it is verified
66 LS/NS ucode binaries onto other Falcons and start them. The process of signature
68 compute the signature, but the HS ucode does.
71      Hardware (Boot ROM running on the Falcon) -> HS ucode -> LS/NS ucode.
75           HS ucode (Booter running on the SEC2) ->
76                LS ucode (GSP-RM running on the GSP)
79      While the CPU can load HS ucode onto a Falcon microcontroller and have it
81      LS or NS ucode and run it. Loading of LS or NS ucode is done mainly by the
82      HS ucode. For example, on an Ampere GPU, after the Booter ucode runs on the
84      the "SEC2-RTOS" ucode at runtime. This presents a problem: there is no
85      component to load the SEC2-RTOS ucode onto the SEC2. The CPU cannot load
87      temporarily made to run HS ucode (which is itself loaded by the CPU via
89      the SEC2-RTOS ucode onto the SEC2 in LS mode. The GSP then resumes
90      running its own GSP-RM LS ucode.