i have another question regarding grub usb ehci support - is such support
under development? is such support are planned to be? what is the current
status?
thanks.
On Sat, Jul 10, 2010 at 7:18 AM, jonatan perry <jonata...@gmail.com> wrote:
> hello ales,
> thank you so much for you detailed answers!
> how would i surely know that grub usb driver would not work on this
> platform?
>
>
>
> On Mon, Jul 5, 2010 at 10:58 PM, Aleš Nesrsta <star...@volny.cz> wrote:
>
>> jonatan perry wrote:
>> > Hello Ales,
>> > Unfortunately, the discussed platform (Lenovo t410 laptop) includes no
>> > UHCI controller along with the EHCI, as well no BIOS USB 1.0 (UHCI)
>> > legacy support.
>> > as I understand from the EHCI specs there are several legacy
>> > registers, named USBLEGSUP and USBLEGCTLSTS, can I assists those
>> > registers in order to achieve legacy support?
>> > I didn't found any source code examples nor additional documentation
>> > regarding those registers.
>> >
>> > any help would be most welcome.
>>
>> Hi,
>>
>> in this case it looks like You unfortunately cannot use USB devices with
>> GRUB2 because GRUB2 does not support EHCI controllers yet.
>>
>> Short and simplified overview - to clarify some things/words/terms:
>>
>> - GRUB2 currently supports OHCI and UHCI USB controllers only (these
>> controllers support USB 1.1 devices only - "low speed" and "full
>> speed").
>>
>> - EHCI is another kind of USB controller than UHCI or OHCI - it supports
>> USB 2.0 devices only ("high speed"). Unfortunately, GRUB2 currently does
>> not have driver module for EHCI.
>>
>> - According to UHCI/OHCI/EHCI specification, "legacy support" means HW
>> emulation of USB mouse&keyboard as PS/2 devices. I.e., USB mouse or
>> keyboard looks like connected via PS/2 port. It is useful for BIOS,
>> bootloaders and some other software (like old DOS) which does not have
>> its own USB support.
>>
>> - Some BIOSes (for example on my computer...) mean by "legacy support"
>> also booting from USB. In this case is connected USB disk "emulated" as
>> HD (or FD) by BIOS. Such kind of booting should work also with GRUB2 and
>> You don't need to use uhci/ohci module.
>>
>> - "Legacy support" DOES NOT (or, better, should not) mean support of
>> USB1.1 devices, i.e., You cannot "switch" EHCI to UHCI (or OHCI) via
>> "legacy support". The only one possible way is to add EHCI support into
>> GRUB2 (new driver module).
>>
>> - USB 2.0 devices (USB disks etc.) are mostly backwards compatible, i.e.
>> they are working also when connected to OHCI/UHCI controllers.
>>
>> Regards
>> Ales
>>
>> >
>> > On Mon, Jul 5, 2010 at 8:14 PM, Aleš Nesrsta <star...@volny.cz> wrote:
>> > > On 07/02/2010 12:30 PM, jonatan perry wrote:
>> > > > Hi all,
>> > > > I am using grub2 uhci.c usb driver for testing new
>> > hardware, on some
>> > > > occuisions the UHCI signature test fails (can be found on
>> > the PCI
>> > > > iteration routine), the driver thest if the controller
>> > founded by PCI
>> > > > has a signature as uhci should have (0x0c0300), on some of
>> > my new
>> > > > hardwares the signature is as EHCI (usb 2.0) means
>> > 0x0c0302, if i
>> > > > change the signature that the driver searches the rest of
>> > the driver
>> > > > fails, probably because i need to activate a legacy bit in
>> > the
>> > > > configuration register in the EHCI Controller.
>> > > EHCI is never alone. It must always have a companion
>> > controller (UHCI or
>> > > OHCI). Also be sure to use either bzr trunk or usb branch.
>> >
>> >
>> > Note:
>> > Unfortunately, according to specification, EHCI can be
>> > installed alone
>> > (without companion UHCI or OHCI controller(s)) but it is
>> > probably very
>> > rare computer HW configuration.
>> > Try command "lspci" in Linux and search for lines with "USB
>> > Controller"
>> > - if You will find EHCI only, You really have "EHCI only"
>> > computer.
>> > But You can have some bad BIOS setting (You should enable USB
>> > 1.1
>> > controller(s) in BIOS.).
>> >
>> >
>> > > > i have searched EHCI Specs for legacy mode and could not
>> > understand
>> > > > how to configure legacy mode... and i hope some of you guy
>> > could help me.
>> > > >
>> > > > thanks!
>> > > >
>> > > >
>> > > > _______________________________________________
>> > > > Grub-devel mailing list
>> > > > Grub-devel@gnu.org
>> > > > http://lists.gnu.org/mailman/listinfo/grub-devel
>> > > >
>> > >
>> > >
>> > > _______________________________________________
>> > > Grub-devel mailing list
>> > > Grub-devel@gnu.org
>> > > http://lists.gnu.org/mailman/listinfo/grub-devel
>> >
>> >
>> > _______________________________________________
>> > Grub-devel mailing list
>> > Grub-devel@gnu.org
>> > http://lists.gnu.org/mailman/listinfo/grub-devel
>> >
>> >
>> >
>> > _______________________________________________
>> > Grub-devel mailing list
>> > Grub-devel@gnu.org
>> > http://lists.gnu.org/mailman/listinfo/grub-devel
>>
>>
>> _______________________________________________
>> Grub-devel mailing list
>> Grub-devel@gnu.org
>> http://lists.gnu.org/mailman/listinfo/grub-devel
>>
>
>
_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
http://lists.gnu.org/mailman/listinfo/grub-devel
