#14844: serial console for EHCI debug port
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Reporter: pulkomandy | Owner: mmlr
Type: bug | Status: new
Priority: normal | Milestone: Unscheduled
Component: Drivers/USB/EHCI | Version: R1/Development
Keywords: | Blocked By:
Blocking: | Has a Patch: 0
Platform: All |
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I discovered that EHCI has support for a "debug port". It's a simplified
protocol for sending data to a specific USB device (of which DIY versions
exist).
https://www.coreboot.org/EHCI_Debug_Port
Documented in EHCI specs.
On machines/chipsets which support this, only one of the USB ports can be
used for this purpose. It's a low level interface, meaning we can use it
even early on in the boot process, without setting up EHCI. So our serial
output could be routed there.
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Ticket URL: <https://dev.haiku-os.org/ticket/14844>
Haiku <https://dev.haiku-os.org>
The Haiku operating system.
