illumos gate

Having corrected the checksum verification for this, the 06-86-04 update file contains two extended signatures, one which matches the file header (0x80665) and one additional (0x80664)

% mdb intel-06-86-04
> ::typedef -r ucodeadm
> 0::print ucode_header_intel_t
{
    uh_header_ver = 0x1
    uh_rev = 0xb00000f
    uh_date = 0x2172021
    uh_signature = 0x80665
    uh_checksum = 0xed327ec0
    uh_loader_ver = 0x1
    uh_proc_flags = 0x1
    uh_body_size = 0x1fba4
    uh_total_size = 0x1fc00
    uh_reserved = [ 0, 0, 0 ]
}

> ::sizeof ucode_header_intel_t
sizeof (ucode_header_intel_t) = 0x30

> 0x1fba4 + 0x30::print ucode_ext_table_intel_t
{
    uet_count = 0x2
    uet_checksum = 0x258af5b2
    uet_reserved = [ 0, 0, 0 ]
    uet_ext_sig = [
        {
            ues_signature = 0x80665
            ues_proc_flags = 0x1
            ues_checksum = 0xed327ec0
        },
    ]
}

> 0x1fba4 + 0x30::print ucode_ext_table_intel_t uet_ext_sig[1]
mdb: index 1 is outside of array bounds [0 .. 0]
uet_ext_sig[1] = {
    uet_ext_sig[1].ues_signature = 0x80664
    uet_ext_sig[1].ues_proc_flags = 0x1
    uet_ext_sig[1].ues_checksum = 0xed327ec1
}

Running the updated ucodeadm generates both files as expected (as hardlinks)

% ./ucodeadm -i -R . intel-06-86-04
% ls -li 000*
     49735 -r--r--r--   3 af       other       127K Jun 24 10:47 00080664-01
     49735 -r--r--r--   3 af       other       127K Jun 24 10:47 00080665-01

I've tested that ucodeadm can now properly process microcode files which have an extended signature table and generate the correct output. I have not booted one of the affected CPUs to confirm that the kernel will accept the generated update.