[PATCH v9 3/4] Boot var automatic management for removable medias
Raymond Mao
raymond.mao at linaro.org
Wed Jun 7 17:05:20 CEST 2023
Changes for complying to EFI spec §3.5.1.1
'Removable Media Boot Behavior'.
Boot variables can be automatically generated during a removable
media is probed. At the same time, unused boot variables will be
detected and removed.
Please note that currently the function 'efi_disk_remove' has no
ability to distinguish below two scenarios
a) Unplugging of a removable media under U-Boot
b) U-Boot existing and booting an OS
Thus currently the boot variables management is not added into
'efi_disk_remove' to avoid boot options being added/erased
repeatedly under scenario b) during power cycles
See TODO comments under function 'efi_disk_remove' for more details
Signed-off-by: Raymond Mao <raymond.mao at linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
---
Changes in v3
- Split the patch into moving and renaming functions and
individual patches for each changed functionality
Changes in v5
- Move function call of efi_bootmgr_update_media_device_boot_option()
from efi_init_variables() to efi_init_obj_list()
Changes in v6
- Revert unrelated changes
Changes in v7
- adapt the return code of function
efi_bootmgr_update_media_device_boot_option()
Changes in v8
- add a note in the commit message for future reference
Changes in v9
- amend the note text in the commit message
- add a TODO comment in 'efi_disk_remove'
lib/efi_loader/efi_disk.c | 18 ++++++++++++++++++
lib/efi_loader/efi_setup.c | 5 +++++
2 files changed, 23 insertions(+)
diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
index d2256713a8..8ccf3dd158 100644
--- a/lib/efi_loader/efi_disk.c
+++ b/lib/efi_loader/efi_disk.c
@@ -687,6 +687,13 @@ int efi_disk_probe(void *ctx, struct event *event)
return -1;
}
+ /* only do the boot option management when UEFI sub-system is initialized */
+ if (efi_obj_list_initialized == EFI_SUCCESS) {
+ ret = efi_bootmgr_update_media_device_boot_option();
+ if (ret != EFI_SUCCESS)
+ return -1;
+ }
+
return 0;
}
@@ -773,6 +780,17 @@ int efi_disk_remove(void *ctx, struct event *event)
return efi_disk_delete_part(dev);
else
return 0;
+
+ /*
+ * TODO A flag to distinguish below 2 different scenarios of this
+ * function call is needed:
+ * a) Unplugging of a removable media under U-Boot
+ * b) U-Boot existing and booting an OS
+ * In case of scenario a), efi_bootmgr_update_media_device_boot_option()
+ * needs to be invoked here to update the boot options and remove the
+ * unnecessary ones.
+ */
+
}
/**
diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
index 58d4e13402..877f3878d6 100644
--- a/lib/efi_loader/efi_setup.c
+++ b/lib/efi_loader/efi_setup.c
@@ -245,6 +245,11 @@ efi_status_t efi_init_obj_list(void)
if (ret != EFI_SUCCESS)
goto out;
+ /* update boot option after variable service initialized */
+ ret = efi_bootmgr_update_media_device_boot_option();
+ if (ret != EFI_SUCCESS)
+ goto out;
+
/* Define supported languages */
ret = efi_init_platform_lang();
if (ret != EFI_SUCCESS)
--
2.25.1
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