[U-Boot] [RFC 3/8] efi_loader: bootmgr: return pointer and size of buffer in loading

AKASHI Takahiro
2019-03-22T02:08:47Z

On Thu, Mar 21, 2019 at 12:41:06PM +0100, Heinrich Schuchardt wrote:
> On 3/5/19 6:53 AM, AKASHI Takahiro wrote:
> > We need to know the size of image loaded so as to be able to use
> > load_image() API at do_bootefi_exec() in a later patch.
> >
> > So change the interface of efi_bootmgr_load().
> >
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > ---
> > include/efi_loader.h | 5 +++--
> > lib/efi_loader/efi_bootmgr.c | 41 +++++++++++++++++++++---------------
> > 2 files changed, 27 insertions(+), 19 deletions(-)
> >
> > diff --git a/include/efi_loader.h b/include/efi_loader.h
> > index 47a51ddc9406..3f51116155ad 100644
> > --- a/include/efi_loader.h
> > +++ b/include/efi_loader.h
> > @@ -564,8 +564,9 @@ struct efi_load_option {
> >
> > void efi_deserialize_load_option(struct efi_load_option *lo, u8 *data);
> > unsigned long efi_serialize_load_option(struct efi_load_option *lo, u8 **data);
> > -void *efi_bootmgr_load(struct efi_device_path **device_path,
> > - struct efi_device_path **file_path);
> > +efi_status_t efi_bootmgr_load(struct efi_device_path **device_path,
> > + struct efi_device_path **file_path,
> > + void **image, efi_uintn_t *size);
> >
> > #else /* CONFIG_IS_ENABLED(EFI_LOADER) */
> >
> > diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> > index 1575c5c09e46..38f3fa15f6ef 100644
> > --- a/lib/efi_loader/efi_bootmgr.c
> > +++ b/lib/efi_loader/efi_bootmgr.c
> > @@ -120,14 +120,17 @@ static void *get_var(u16 *name, const efi_guid_t *vendor,
> > * if successful. This checks that the EFI_LOAD_OPTION is active (enabled)
> > * and that the specified file to boot exists.
> > */
> > -static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
> > - struct efi_device_path **file_path)
> > +static efi_status_t try_load_entry(u16 n,
> > + struct efi_device_path **device_path,
> > + struct efi_device_path **file_path,
> > + void **image, efi_uintn_t *image_size)
> > {
> > struct efi_load_option lo;
> > u16 varname[] = L"Boot0000";
> > u16 hexmap[] = L"0123456789ABCDEF";
> > - void *load_option, *image = NULL;
> > + void *load_option;
> > efi_uintn_t size;
> > + efi_status_t ret;
> >
> > varname[4] = hexmap[(n & 0xf000) >> 12];
> > varname[5] = hexmap[(n & 0x0f00) >> 8];
> > @@ -136,18 +139,17 @@ static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
> >
> > load_option = get_var(varname, &efi_global_variable_guid, &size);
> > if (!load_option)
> > - return NULL;
> > + return EFI_LOAD_ERROR;
> >
> > efi_deserialize_load_option(&lo, load_option);
> >
> > if (lo.attributes & LOAD_OPTION_ACTIVE) {
> > u32 attributes;
> > - efi_status_t ret;
> >
> > debug("%s: trying to load \"%ls\" from %pD\n",
> > __func__, lo.label, lo.file_path);
> >
> > - ret = efi_load_image_from_path(lo.file_path, &image, &size);
> > + ret = efi_load_image_from_path(lo.file_path, image, image_size);
> >
>
> This call to efi_load_image_from_path() leads to duplication of logic.
>
> Why don't we simply call EFI_CALL(efi_load_image())) here and if it
> succeeds return from efi_bootmgr_load()?

Make sense. It will make do_bootefi_exec() simpler.
This will also give us a reason why we have do_efibootmgr() apart
from do_boot_efi().

Thanks,
-Takahiro Akashi

> Best regards
>
> Heinrich
>
> > if (ret != EFI_SUCCESS)
> > goto error;
> > @@ -164,12 +166,14 @@ static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
> >
> > printf("Booting: %ls\n", lo.label);
> > efi_dp_split_file_path(lo.file_path, device_path, file_path);
> > + } else {
> > + ret = EFI_LOAD_ERROR;
> > }
> >
> > error:
> > free(load_option);
> >
> > - return image;
> > + return ret;
> > }
> >
> > /*
> > @@ -177,12 +181,12 @@ error:
> > * EFI variable, the available load-options, finding and returning
> > * the first one that can be loaded successfully.
> > */
> > -void *efi_bootmgr_load(struct efi_device_path **device_path,
> > - struct efi_device_path **file_path)
> > +efi_status_t efi_bootmgr_load(struct efi_device_path **device_path,
> > + struct efi_device_path **file_path,
> > + void **image, efi_uintn_t *image_size)
> > {
> > u16 bootnext, *bootorder;
> > efi_uintn_t size;
> > - void *image = NULL;
> > int i, num;
> > efi_status_t ret;
> >
> > @@ -201,9 +205,9 @@ void *efi_bootmgr_load(struct efi_device_path **device_path,
> > (efi_guid_t *)&efi_global_variable_guid,
> > 0, 0, &bootnext));
> > if (ret == EFI_SUCCESS) {
> > - image = try_load_entry(bootnext,
> > - device_path, file_path);
> > - if (image)
> > + ret = try_load_entry(bootnext, device_path, file_path,
> > + image, image_size);
> > + if (ret == EFI_SUCCESS)
> > goto error;
> > }
> > }
> > @@ -212,19 +216,22 @@ void *efi_bootmgr_load(struct efi_device_path **device_path,
> > bootorder = get_var(L"BootOrder", &efi_global_variable_guid, &size);
> > if (!bootorder) {
> > printf("BootOrder not defined\n");
> > + ret = EFI_NOT_FOUND;
> > goto error;
> > }
> >
> > num = size / sizeof(uint16_t);
> > for (i = 0; i < num; i++) {
> > - debug("%s: trying to load Boot%04X\n", __func__, bootorder[i]);
> > - image = try_load_entry(bootorder[i], device_path, file_path);
> > - if (image)
> > + debug("%s: trying to load Boot%04X\n", __func__,
> > + bootorder[i]);
> > + ret = try_load_entry(bootorder[i], device_path, file_path,
> > + image, image_size);
> > + if (ret == EFI_SUCCESS)
> > break;
> > }
> >
> > free(bootorder);
> >
> > error:
> > - return image;
> > + return ret;
> > }
> >
>