[coreboot] USB 2.0 EHCI debug dongle doesn't print logs (at Lenovo G505S)

Ivan Ivanov qmastery16 at gmail.com
Sun Sep 30 17:55:11 CEST 2018

Thank you very much for your help, Nico! Enabling CONFIG_CONSOLE_USB
indeed got FT232H working! :-) I wonder why CONFIG_CONSOLE_USB isn't
enabled by default if CONFIG_USBDEBUG is enabled... Maybe this default
behaviour should be changed?

P.S. works even together with CONFIG_USBDEBUG_IN_ROMSTAGE

2018-09-30 14:23 GMT+03:00, Nico Huber <nico.h at gmx.de>:
> Hi Ivan,
> On 9/28/18 11:50 PM, Ivan Ivanov wrote:
>> Thank you for spkmodem comments, now I'm trying out a more reliable
>> way - FT232H dongle - to extract the logs from AMD Lenovo G505S. I
>> plug it into the correct port - USB 2.0 at laptop's right side.
>> However it doesn't print anything except this short test message:
>> --- /* Perform a small write. */
>> --- ret = dbgp_bulk_write_x(&pipe[DBGP_CONSOLE_EPOUT], "USB\r\n", 5);
>> ------ line 322 of ./coreboot/src/drivers/usb/gadget.c
>> Thinking that it breaks during the relocation from romstage to
>> ramstage (migrate_ehci_debug function at ehci_debug.c ?) , I disabled
>> CONFIG_USBDEBUG_IN_ROMSTAGE - but the results are the same: only "USB"
>> message. I could see
>> --- dprintk(BIOS_INFO, "Test write done\n");
>> ------ line 328 of ./coreboot/src/drivers/usb/gadget.c
>> at cbmem logs, but even that doesn't get copied to FT232H output.
> the purpose of dprintk() here is to only print when EHCI debug is _not_
> activated yet. Otherwise the code trying to print something would be
> called recursively. But it might actually work at this early point,
> with proper configuration (see below).
>> Please could you take a look at my coreboot .config and cbmem logs,
>> what if this FT232H dongle doesn't get selected as console output for
>> some reason? CONFIG_CONSOLE_CBMEM is still enabled, but maybe I should
>> disable it?
> You are missing CONFIG_CONSOLE_USB.
> Nico

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