[PATCH v2 4/4] efi: add helper functions to insert pmem node for DT fixup
Sughosh Ganu
sughosh.ganu at linaro.org
Mon Jan 6 10:14:27 CET 2025
On Fri, 3 Jan 2025 at 22:31, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 03.12.24 17:36, Sughosh Ganu wrote:
> > The EFI HTTP boot puts the iso installer image at some location in
> > memory which needs to be reserved in the devicetree as persistent
> > memory (pmem). Add helper functions which add this pmem node when the
> > EFI_DT_FIXUP protocol's fixup callback is invoked.
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> > ---
> > Changes since V1:
> > * Use log_err() to print the error message in image_setup_libfdt()
> > * Remove "ERROR:" from the error print in image_setup_libfdt()
> >
> > boot/image-fdt.c | 9 +++++++++
> > include/efi_loader.h | 17 +++++++++++++++++
> > lib/efi_loader/efi_bootmgr.c | 21 +++++++++++++++++++++
> > lib/efi_loader/efi_helper.c | 12 ++++++++++++
> > 4 files changed, 59 insertions(+)
> >
> > diff --git a/boot/image-fdt.c b/boot/image-fdt.c
> > index 3d5b6f9e2dc..de479d3ffa0 100644
> > --- a/boot/image-fdt.c
> > +++ b/boot/image-fdt.c
> > @@ -11,6 +11,7 @@
> > #include <command.h>
> > #include <fdt_support.h>
> > #include <fdtdec.h>
> > +#include <efi_loader.h>
> > #include <env.h>
> > #include <errno.h>
> > #include <image.h>
> > @@ -648,6 +649,14 @@ int image_setup_libfdt(struct bootm_headers *images, void *blob, bool lmb)
> > if (!ft_verify_fdt(blob))
> > goto err;
> >
> > + if (CONFIG_IS_ENABLED(EFI_HTTP_BOOT)) {
> > + fdt_ret = fdt_efi_pmem_setup(blob);
> > + if (fdt_ret) {
> > + log_err("HTTP boot pmem fixup failed\n");
> > + goto err;
> > + }
> > + }
> > +
> > /* after here we are using a livetree */
> > if (!of_live_active() && CONFIG_IS_ENABLED(EVENT)) {
> > struct event_ft_fixup fixup;
> > diff --git a/include/efi_loader.h b/include/efi_loader.h
> > index 24e40799eee..87b9a6e4da0 100644
> > --- a/include/efi_loader.h
> > +++ b/include/efi_loader.h
> > @@ -748,6 +748,15 @@ bool efi_varname_is_load_option(u16 *var_name16, int *index);
> > efi_status_t efi_next_variable_name(efi_uintn_t *size, u16 **buf,
> > efi_guid_t *guid);
> >
> > +/**
> > + * fdt_efi_pmem_setup() - Setup the pmem node in the devicetree
> > + *
> > + * @fdt: Pointer to the devicetree
> > + *
> > + * Return: 0 on success, negative on failure
> > + */
> > +int fdt_efi_pmem_setup(void *fdt);
> > +
> > /**
> > * efi_size_in_pages() - convert size in bytes to size in pages
> > *
> > @@ -964,6 +973,14 @@ efi_status_t efi_set_load_options(efi_handle_t handle,
> > void *load_options);
> > efi_status_t efi_bootmgr_load(efi_handle_t *handle, void **load_options);
> >
> > +/**
> > + * efi_bootmgr_pmem_setup() - Put a pmem node for UEFI HTTP installers
> > + *
> > + * @fdt: Pointer to the DT blob
> > + * Return: status code
> > + */
> > +efi_status_t efi_bootmgr_pmem_setup(void *fdt);
> > +
> > /**
> > * struct efi_image_regions - A list of memory regions
> > *
> > diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> > index b906e53e26e..db4eb6a7376 100644
> > --- a/lib/efi_loader/efi_bootmgr.c
> > +++ b/lib/efi_loader/efi_bootmgr.c
> > @@ -41,6 +41,8 @@ struct uridp_context {
> > efi_handle_t mem_handle;
> > };
> >
> > +static struct uridp_context *uctx;
> > +
> > const efi_guid_t efi_guid_bootmenu_auto_generated =
> > EFICONFIG_AUTO_GENERATED_ENTRY_GUID;
> >
> > @@ -427,6 +429,7 @@ static efi_status_t efi_bootmgr_release_uridp(struct uridp_context *ctx)
> >
> > efi_free_pool(ctx->loaded_dp);
> > free(ctx);
> > + uctx = NULL;
> >
> > return ret == EFI_SUCCESS ? ret2 : ret;
> > }
> > @@ -447,6 +450,23 @@ static void EFIAPI efi_bootmgr_http_return(struct efi_event *event,
> > EFI_EXIT(ret);
> > }
> >
> > +/**
> > + * efi_bootmgr_pmem_setup() - Put a pmem node for UEFI HTTP installers
> > + *
> > + * @fdt: Pointer to the DT blob
> > + * Return: status code
> > + */
> > +efi_status_t efi_bootmgr_pmem_setup(void *fdt)
> > +{
> > + if (!uctx) {
> > + log_warning("No EFI HTTP boot context found\n");
>
> This function is called if CONFIG_EFI_HTTP_BOOT=y. This configuration
> setting allows booting via HTTP but does not require it. The warning
> makes no sense when booting from a block device.
Okay. I can remove the warning.
>
> The image type is orthogonal to the way you load it. Pmem support in
> Linux is not related to UEFI. Please, remove the dependency of pmem
> support on UEFI HTTP boot.
>
> If the object to be booted is a disk image, we can create a block device
> in memory for it and then should be able to apply all standard boot
> methods on it.
I think this was discussed earlier [1]. As things stand today, the
only context in which an installer ISO image is loaded to memory is
through the EFI HTTP boot path.
-sughosh
[1] - https://lists.denx.de/pipermail/u-boot/2024-November/571335.html
>
> Best regards
>
> Heinrich
>
> > + return EFI_SUCCESS;
> > + }
> > +
> > + return !fdt_fixup_pmem_region(fdt, uctx->image_addr, uctx->image_size) ?
> > + EFI_SUCCESS : EFI_INVALID_PARAMETER;
> > +}
> > +
> > /**
> > * try_load_from_uri_path() - Handle the URI device path
> > *
> > @@ -476,6 +496,7 @@ static efi_status_t try_load_from_uri_path(struct efi_device_path_uri *uridp,
> > if (!ctx)
> > return EFI_OUT_OF_RESOURCES;
> >
> > + uctx = ctx;
> > s = env_get("loadaddr");
> > if (!s) {
> > log_err("Error: loadaddr is not set\n");
> > diff --git a/lib/efi_loader/efi_helper.c b/lib/efi_loader/efi_helper.c
> > index bf96f61d3d0..6fae37ad617 100644
> > --- a/lib/efi_loader/efi_helper.c
> > +++ b/lib/efi_loader/efi_helper.c
> > @@ -313,6 +313,18 @@ int efi_unlink_dev(efi_handle_t handle)
> > return 0;
> > }
> >
> > +/**
> > + * fdt_efi_pmem_setup() - Setup the pmem node in the devicetree
> > + *
> > + * @fdt: Pointer to the devicetree
> > + *
> > + * Return: 0 on success, negative on failure
> > + */
> > +int fdt_efi_pmem_setup(void *fdt)
> > +{
> > + return efi_bootmgr_pmem_setup(fdt) == EFI_SUCCESS ? 0 : -1;
> > +}
> > +
> > static int u16_tohex(u16 c)
> > {
> > if (c >= '0' && c <= '9')
>
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