TPMs would not have helped here. The problem is that some boot code must come first. That bit of boot code, if it can be rooted, can lie about the code it's l

TPMs would not have helped here. The problem is that some boot code must come first. That bit of boot code, if it can be rooted, can lie about the code it's loading, and so the TPM can't help. The only way a TPM could help is if it was the boot loader. But that can't be, not unless the TPM were a firmware TPM running in tight cooperation with the ME.