> SATA driver init takes 100 to 200 ms even without a real disk
That's pretty interesting. Wonder what it is doing?
That's pretty interesting. Wonder what it is doing?
It wouldn’t necessarily have to be done synchronously up front at all, except when the BIOS hands off control of the system to the SATA controller it expects that afterward it has a definitive list of available boot devices and their properties, for selection/display in the boot menu and BIOS configuration.
Theoretically with UEFI and it’s NVRAM-resident settings, a boot device could be expressed as a namespace and path, and the firmware need not enumerate devices until it has determined that there’s a need to search for alternative/fallback boot devices, but the stack hasn’t been updated with that in mind.
The hard drive predelay is also not as obsolete as you may think; I've encountered high-capacity SATA SSDs that take a surprisingly long time to come up after being hotplugged, to the point that Linux doesn't always succeed in bringing up the link on the first try.
I’m willing to bet if the stack enforced tighter tolerances for modern non-rotating disks, manufacturers wouldn’t be able to slip such shoddy firmwares into production.