Re: [PATCH v2 4/4] efi: add helper functions to insert pmem node for DT fixup

On Fri, 3 Jan 2025 at 22:31, Heinrich Schuchardt xypron.glpk@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@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')