Hi Michael, On Wed, Mar 13, 2024 at 10:30 PM Michael Kelley <mhklinux@xxxxxxxxxxx> wrote: > By default, Linux doesn't verify checksums when accessing ACPI tables > during early boot, though you can add "acpi_force_table_verification" > to the kernel boot line. The default is shown in dmesg like this: > > [ 0.004419] ACPI: Early table checksum verification disabled > > The checksum of all tables is checked slightly later in boot, though > it's after my entropy code has run. Without the checksum fixup, > this error is output: > > [ 0.053752] ACPI BIOS Warning (bug): Incorrect checksum in table > [OEM0] - 0x8B, should be 0x82 (20230628/utcksum-58) > > At this point, the checksum error doesn't really matter, but I > don't want the warning showing up. I need to experiment a > bit, but probably the best approach is to set the data length to > zero (and adjust the checksum) while leaving the rest of the ACPI > table header intact. It will be more difficult to make the table > disappear entirely as it appears in a global list of ACPI tables. That makes sense. If the length is getting set to zero and the data itself zeroed, I would assume that the checksum evaluates to some constant value (0? ~0? dunno how it's computed), so that should ease things a bit. Jason
