Got it. the value of firmware will increase all the time until you power off the machine. I mean during system warm reset, TSC will not be reseted. CPU : Skylake
From: Mantas Mikulėnas <[email protected]> Sent: 2021年10月13日 20:33 To: jiansong Xu <[email protected]> Cc: [email protected] Subject: [External] : Re: [systemd-devel] firmware times reported were incorrect. Looks like boot-timestamps.c first tries to read the ACPI FPDT table (it seems acpi-fpdt.c uses the "OS Loader StartImage Start" and "ExitBootServices Exit" fields), but if that's unavailable, then it uses timestamps stored by systemd-boot in EFI variables (/sys/firmware/efi/efivars/LoaderTime*). The latter seems to be estimating it from RDTSC (src/boot/efi/util.c). On Wed, Oct 13, 2021 at 3:05 PM jiansong Xu <[email protected]<mailto:[email protected]>> wrote: This is bios from oracle, we noticed that the firmware times reported were incorrect. Startup finished in 59min 7.944s (firmware) + 33.051s (loader) + 4.428s (kernel) + 1min 18.870s (initrd) + 44.494s (userspace) = 1h 1min 48.789s May I ask what is the source of the firmware ? is it read from acpi table? -- Mantas Mikulėnas
