[PATCH v9 02/11] efi_loader: Add a test app

[Ilias Apalodimas]

Hi Heinrich



On Wed, 30 Oct 2024 at 18:55, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 10/29/24 20:22, Simon Glass wrote:
> > Add a simple app to use for testing. This is intended to do whatever it
> > needs to for testing purposes. For now it just prints a message and
> > exits boot services.
> >
> > There was a considerable amount of discussion about whether it is OK to
> > call exit-boot-services and then return to U-Boot. This is not normally
> > done in a real application, since exit-boot-services is used to
> > completely disconnect from U-Boot. However, since this is a test, we
> > need to check the results of running the app, so returning is necessary.
> > It works correctly and it provides a nice model of how to test the EFI
> > code in a simple way.
> >
> > Signed-off-by: Simon Glass <sjg at chromium.org>
> > ---
> >
> > Changes in v9:
> > - Update license
> > - Fix 'sevices' typo
> >
> > Changes in v7:
> > - Update commit message
> >
> >   lib/efi_loader/Kconfig   | 10 ++++++
> >   lib/efi_loader/Makefile  |  1 +
> >   lib/efi_loader/testapp.c | 68 ++++++++++++++++++++++++++++++++++++++++
> >   3 files changed, 79 insertions(+)
> >   create mode 100644 lib/efi_loader/testapp.c
> >
> > diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> > index 37572c82f54..44319729bda 100644
> > --- a/lib/efi_loader/Kconfig
> > +++ b/lib/efi_loader/Kconfig
> > @@ -584,6 +584,16 @@ config BOOTEFI_HELLO_COMPILE
> >         No additional space will be required in the resulting U-Boot binary
> >         when this option is enabled.
> >
> > +config BOOTEFI_TESTAPP_COMPILE
> > +     bool "Compile an EFI test app for testing"
> > +     default y
> > +     help
> > +       This compiles an app designed for testing. It is packed into an image
> > +       by the test.py testing frame in the setup_efi_image() function.
> > +
> > +       No additional space will be required in the resulting U-Boot binary
> > +       when this option is enabled.
> > +
> >   endif
> >
> >   source "lib/efi/Kconfig"
> > diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
> > index 8ec240cb864..7c8b2dd1ad6 100644
> > --- a/lib/efi_loader/Makefile
> > +++ b/lib/efi_loader/Makefile
> > @@ -20,6 +20,7 @@ apps-$(CONFIG_EFI_LOAD_FILE2_INITRD) += initrddump
> >   ifeq ($(CONFIG_GENERATE_ACPI_TABLE),)
> >   apps-y += dtbdump
> >   endif
> > +apps-$(CONFIG_BOOTEFI_TESTAPP_COMPILE) += testapp
> >
> >   obj-$(CONFIG_CMD_BOOTEFI_HELLO) += helloworld_efi.o
> >   obj-$(CONFIG_EFI_BOOTMGR) += efi_bootmgr.o
> > diff --git a/lib/efi_loader/testapp.c b/lib/efi_loader/testapp.c
> > new file mode 100644
> > index 00000000000..a28fc17ce5b
> > --- /dev/null
> > +++ b/lib/efi_loader/testapp.c
> > @@ -0,0 +1,68 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Hello world EFI application
> > + *
> > + * Copyright 2024 Google LLC
> > + * Written by Simon Glass <sjg at chromium.org>
> > + *
> > + * This test program is used to test the invocation of an EFI application.
> > + * It writes a few messages to the console and then exits boot services
> > + */
> > +
> > +#include <efi_api.h>
> > +
> > +static const efi_guid_t loaded_image_guid = EFI_LOADED_IMAGE_PROTOCOL_GUID;
> > +
> > +static struct efi_system_table *systable;
> > +static struct efi_boot_services *boottime;
> > +static struct efi_simple_text_output_protocol *con_out;
> > +
> > +/**
> > + * efi_main() - entry point of the EFI application.
> > + *
> > + * @handle:  handle of the loaded image
> > + * @systab:  system table
> > + * Return:   status code
> > + */
> > +efi_status_t EFIAPI efi_main(efi_handle_t handle,
> > +                          struct efi_system_table *systab)
> > +{
> > +     struct efi_loaded_image *loaded_image;
> > +     efi_status_t ret;
> > +     efi_uintn_t map_size;
> > +     efi_uintn_t map_key;
> > +     efi_uintn_t desc_size;
> > +     u32 desc_version;
> > +
> > +     systable = systab;
> > +     boottime = systable->boottime;
> > +     con_out = systable->con_out;
> > +
> > +     /* Get the loaded image protocol */
> > +     ret = boottime->open_protocol(handle, &loaded_image_guid,
> > +                                   (void **)&loaded_image, NULL, NULL,
> > +                                   EFI_OPEN_PROTOCOL_GET_PROTOCOL);
> > +     if (ret != EFI_SUCCESS) {
> > +             con_out->output_string
> > +                     (con_out, u"Cannot open loaded image protocol\r\n");
> > +             goto out;
> > +     }
> > +
> > +     /* UEFI requires CR LF */
> > +     con_out->output_string(con_out, u"U-Boot test app for EFI_LOADER\r\n");
> > +
> > +out:
> > +     map_size = 0;
> > +     ret = boottime->get_memory_map(&map_size, NULL, &map_key, &desc_size,
> > +                                    &desc_version);
> > +     con_out->output_string(con_out, u"Exiting boot services\n");
> > +
> > +     /* exit boot services so that this part of U-Boot can be tested */
> > +     boottime->exit_boot_services(handle, map_key);
>
> Hello Simon,
>
> I am not NAKing this patch. But maybe you could rethink if this call
> tells us anything new about the correct function of ExitBootServices().
>
> We already have a test of ExitBootServices() in lib/efi_selftest/ and
> maybe we should extend that test to check more.
>
> By removing ExitBootServices() we could keep U-Boot in a well defined
> state which will allow us to run any number of bootmeth tests in
> sequence and keep the EFI sub-system in a consistent state.

FWIW I proposed exactly the same in [0].

[0] https://lore.kernel.org/u-boot/CAC_iWjJYqrh6MS50d6MxdStJFGg2pWnf1PHwQ9muYDPmOBP7Lg@mail.gmail.com/

Thanks
/Ilias
>
> Best regards
>
> Heinrich
>
>
> > +
> > +     /* now exit for real */
> > +     ret = boottime->exit(handle, ret, 0, NULL);
> > +
> > +     /* We should never arrive here */
> > +     return ret;
> > +}
>