(Ab)using Linux as a Trusted Bootloader
summary
Petitboot boots the next kernel via kexec while reusing Linux drivers; a set of kernel changes adds an kexec_file_load hook so the kernel and initramfs get measured, and IMA gains IMA policy PCR flexibility (upstream in 4.8) so measurements can target arbitrary PCRs. The IMA log is serialized across kexec and reattached via device-tree nodes on POWER. Work runs cross‑platform (x86 VM and POWER hardware), mostly works, with unresolved device‑tree passing and command‑line/buffer measurement gaps.
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chapters (14)
- 0:00Introduction
- 0:30Overview
- 0:56TPM
- 1:26Measuring
- 2:38What we need
- 5:38KExec
- 6:36Adding Measurements
- 8:15Fixing Measurements
- 9:19IMA
- 10:11Limitations
- 11:22Measures
- 13:10Serializing
- 14:20Device Tree
- 15:38Final remarks
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