Re: [U-Boot-Users] USB Host support
Dear David,
Please keep the list on CC:
David.Saada@ecitele.com writes:
The higher level interfaces are all in place and there are drivers for different controllers such as OHCI and UHCI. Some of these controller drivers are still board dependant, but we're in the progress of merging them together into one generic driver. If you happen to have an OHCI Controller, don't miss "doc/README.generic_usb_ohci".
Is there a plan to support EHCI as well?
There are already boards supporting USB 2.0. Grep for "USB_2_0_DEVICE".
Writing is not supported so far, but reading works fine on a number of architectures and boards.
Do you plan to support writing as well?
No, not at the moment. USB is typically used for updating components of the system for which reading files is sufficient. What do you need support for writing for?
Viele Grüße / Best regards
Markus Klotzbücher
-- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office@denx.de
Dear David,
Please keep the list on CC:
Sorry. Wrong reply button...
The higher level interfaces are all in place and there are drivers for different controllers such as OHCI and UHCI. Some of these controller drivers are still board dependant, but we're in the progress of merging them together into one generic driver. If you happen to have an OHCI Controller, don't miss "doc/README.generic_usb_ohci".
Is there a plan to support EHCI as well?
There are already boards supporting USB 2.0. Grep for "USB_2_0_DEVICE".
Thanks. Will do.
Writing is not supported so far, but reading works fine on a number of architectures and boards.
Do you plan to support writing as well?
No, not at the moment. USB is typically used for updating components of the system for which reading files is sufficient. What do you need support for writing for?
Let me elaborate a bit: We're thinking of having a kind of a "Disk on key" device as our primary non volatile storage. The Linux software image will be on this device, so we'll need to boot from it as well. As this is an MPC85xx based board, having no embedded USB controller, we'll also need an external PCI to USB 2.0 host controller. Writing may be needed as in our current boot process the boot application writes some temporary files on the HD (and it's also needed at development stage, when there is no image on the disk). I basically would like to know how painful it is to have all this ticking with the current u-boot support.
Best regards, David.
In message 11273166.post@talk.nabble.com you wrote:
Let me elaborate a bit: We're thinking of having a kind of a "Disk on key" device as our primary non volatile storage. The Linux software image will be on this device, so we'll need to boot from it as well. As this is an MPC85xx based board, having no embedded USB controller, we'll also need an external PCI to USB 2.0 host controller. Writing may be needed as in our current boot process the boot application writes some temporary files on the HD (and it's also needed at development stage, when there is no image on the disk).
It is not needed. Boot Linux over Ethernet, and use the running Linux system to write the files.
I basically would like to know how painful it is to have all this ticking with the current u-boot support.
It *is* painful, as you would have to add write support both to the USB drivers (including re-testing on a lot of boards) *plus* to the file system drivers (including re-testing on a lot of boards).
It's simply not worth the effort. U-Boot is a boot loader, and if you need the services of a typical OS (like full file system support) then you should just boot an OS - that's what U-Bootis really good in.
Best regards,
Wolfgang Denk
The higher level interfaces are all in place and there are drivers for different controllers such as OHCI and UHCI. Some of these controller drivers are still board dependant, but we're in the progress of merging them together into one generic driver. If you happen to have an OHCI Controller, don't miss "doc/README.generic_usb_ohci".
Is there a plan to support EHCI as well?
There are already boards supporting USB 2.0. Grep for "USB_2_0_DEVICE".
Marcus - of what I've seen (in the USB tree), the USB_2_0 support is for a CPU specific (4xx) EHCI controller. My question was about a generic EHCI controller driver (like the OHCI one), as we plan to use a PCI based USB host controller. I guess we can operate it in the OHCI mode at boot stage and get a slower boot if generic EHCI support is not planned in the near future.
Best regards, David.
participants (3)
-
David Saada -
Markus Klotzbücher -
Wolfgang Denk