On Mon, Aug 12, 2019 at 01:46:35PM -0700, Stephen Boyd wrote: > Quoting Jarkko Sakkinen (2019-08-09 13:31:04) > > On Tue, 2019-08-06 at 15:07 -0700, Stephen Boyd wrote: > > > From: Andrey Pronin <apronin@xxxxxxxxxxxx> > > > > > > Add TPM2.0 PTP FIFO compatible SPI interface for chips with Cr50 > > > firmware. The firmware running on the currently supported H1 > > > Secure Microcontroller requires a special driver to handle its > > > specifics: > > > > > > - need to ensure a certain delay between spi transactions, or else > > > the chip may miss some part of the next transaction; > > > - if there is no spi activity for some time, it may go to sleep, > > > and needs to be waken up before sending further commands; > > > - access to vendor-specific registers. > > > > Which Chromebook models have this chip? > > Pretty much all Chromebooks released in the last year or two have this > chip in them. I don't have an exhaustive list, but you can usually check > this by putting your device into dev mode and then looking at the driver > attached to the TPM device in sysfs or by grepping the dmesg output for > cr50. > > > > > If I had an access to one, how do I do kernel testing with it i.e. > > how do I get it to boot initramfs and bzImage from a USB stick? > > > > > > You can follow the developer guide[1] and build a USB image for the > board you have. You can usually checkout the latest upstream kernel in > place of where the kernel is built from in the chroot, typically > ~/trunk/src/third_party/kernel/<version number>. The build should pick > up that it's an upstream tree and try to use some default defconfig. > This driver isn't upstream yet, so you may need to enable it in the > defconfig, located in > ~/trunk/src/third_party/chromiumos-overlay/eclass/cros-kernel/ so that > the driver is actually built. After that, use 'cros flash' to flash the > new kernel image to your USB stick and boot from USB with 'ctrl+u' and > you should be on your way to chromeos kernel testing. > > [1] https://chromium.googlesource.com/chromiumos/docs/+/master/developer_guide.md Hey, thanks for info! I'll see if I can get my hands on one. /Jarkko
