[PATCH v8 2/8] efi_loader: Add a test app

[Simon Glass]

Hi Heinrich,

On Mon, 28 Oct 2024 at 07:11, Heinrich Schuchardt <xypron.glpk at gmx.de>
wrote:
>
> On 10/22/24 14:00, 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>
> > ---
> >
> > (no changes since v7)
> >
> > 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 69b2c9360d8..6ced29da719 100644
> > --- a/lib/efi_loader/Kconfig
> > +++ b/lib/efi_loader/Kconfig
> > @@ -565,6 +565,16 @@ 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 00d18966f9e..87131ab911d 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..feb444c92e9
> > --- /dev/null
> > +++ b/lib/efi_loader/testapp.c
> > @@ -0,0 +1,68 @@
> > +// SPDX-License-Identifier: GPL-2.0+
>
> This is not a valid SPDX identifier. Please, use 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 sevices\n");
>
> %s/sevices/services/g
>
> > +
> > +     /* exit boot services so that this part of U-Boot can be tested */
> > +     boottime->exit_boot_services(handle, map_key);
> > +
> > +     /* now exit for real */
> > +     ret = boottime->exit(handle, ret, 0, NULL);
>
> As written before boot services are not available after
> ExitBootServices(). Please, call the ResetSystem() service.

I already explained this. If I call reset then U-Boot exits and the console
output cannot be checked by the C test. If I tell sandbox's reset-driver to
ignore the reset request, then it also doesn't come back to the test.

>
>
> > +
> > +     /* We should never arrive here */
> > +     return ret;
>
> After ExitBootServices() you must not return.
>
> You can just do an endless loop if ResetSystem() fails:
>
> for (;;);

No, because I need to check the output of the app. Please can you try to
run this test so you can see what it is doing?

Regards,
Simon