On 21.10.20 13:41, Ilias Apalodimas wrote:
Hi Heinrich,
On Wed, Oct 21, 2020 at 12:17:29PM +0200, Heinrich Schuchardt wrote:
On 10/21/20 9:32 AM, Ilias Apalodimas wrote:
U-Boot Driver Model is supposed to remove devices with either DM_REMOVE_ACTIVE_DMA or DM_REMOVE_OS_PREPARE flags set, before exiting. Our bootm command does that by explicitly calling calling "dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL);" and we also disable any USB devices.
The EFI equivalent is doing none of those at the moment. As a result probing an fTPM driver now renders it unusable in Linux. During our (*probe) callback we open a session with OP-TEE, which is supposed to close with our (*remove) callback. Since the (*remove) is never called, once we boot into Linux and try to probe the device again we are getting a busy error response. We also never free
So let's fix this by mimicking what bootm does and disconnect devices when efi_exit_boot_services() is called. Note that for the OP-TEE case and in particular any subsequent bootloader that wants to use a device (e.g GRUB) will need to call exit_boot_services() in order to close the session.
Hello Ilias,
thanks for the patch. Adding the function calls looks correct to me,
Well the only doubt I have is what if GRUB has to extend some PCRs before calling Linux? Any idea if it's currently calling ExitBootSevices? I was considering if it would be a better idea to call the device unbinding during some kind of "exit" from U-boot's EFI code. (i.e before StartImage)
ExitBootServices() is called by the Linux EFI stub in function allocate_new_fdt_and_exit_boot().
If GRUB would call ExitBootServices(), it would not be able to launch the EFI stub via StartImage().
Best regards
Heinrich
but sandbox_spl_defconfig gives me a compile time error with this patch, cf. https://gitlab.denx.de/u-boot/custodians/u-boot-efi/-/jobs/166842
You might want to use Travis CI before resubmitting.
Ok will do.
Thanks /Ilias
Best regards
Heinrich
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
lib/efi_loader/efi_boottime.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c index bf78176217c6..25e6cf0fe719 100644 --- a/lib/efi_loader/efi_boottime.c +++ b/lib/efi_loader/efi_boottime.c @@ -18,6 +18,8 @@ #include <pe.h> #include <u-boot/crc.h> #include <watchdog.h> +#include <dm/device.h> +#include <dm/root.h>
DECLARE_GLOBAL_DATA_PTR;
@@ -1994,7 +1996,10 @@ static efi_status_t EFIAPI efi_exit_boot_services(efi_handle_t image_handle, list_del(&evt->link); }
if IS_ENABLED(CONFIG_USB_DEVICE)
udc_disconnect();board_quiesce_devices();
dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL);
/* Patch out unsupported runtime function */ efi_runtime_detach();