[PATCH 1/2] efi: add more helper functions to write EFI variables

[PATCH 1/2] efi: add more helper functions to write EFI variables

[Michael Olbrich]

Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
---
 common/efi/payload/init.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/common/efi/payload/init.c b/common/efi/payload/init.c
index b990b54b2678..19be7ff07fb6 100644
--- a/common/efi/payload/init.c
+++ b/common/efi/payload/init.c
@@ -107,6 +107,44 @@ int efi_set_variable_usec(char *name, efi_guid_t *vendor, uint64_t usec)
 				(strlen(buf)+1) * sizeof(wchar_t));
 }
 
+static int efi_set_variable_printf(char *name, efi_guid_t *vendor, const char *fmt, ...)
+{
+	va_list args;
+	char *buf;
+	wchar_t *buf16;
+
+	va_start(args, fmt);
+	buf = xvasprintf(fmt, args);
+	va_end(args);
+	buf16 = xstrdup_char_to_wchar(buf);
+
+	return efi_set_variable(name, vendor,
+				EFI_VARIABLE_BOOTSERVICE_ACCESS |
+				EFI_VARIABLE_RUNTIME_ACCESS, buf16,
+				(strlen(buf)+1) * sizeof(wchar_t));
+	free(buf);
+	free(buf16);
+}
+
+static int efi_set_variable_uint64_le(char *name, efi_guid_t *vendor, uint64_t value)
+{
+	uint8_t buf[8];
+
+	buf[0] = (uint8_t)(value >> 0U & 0xFF);
+	buf[1] = (uint8_t)(value >> 8U & 0xFF);
+	buf[2] = (uint8_t)(value >> 16U & 0xFF);
+	buf[3] = (uint8_t)(value >> 24U & 0xFF);
+	buf[4] = (uint8_t)(value >> 32U & 0xFF);
+	buf[5] = (uint8_t)(value >> 40U & 0xFF);
+	buf[6] = (uint8_t)(value >> 48U & 0xFF);
+	buf[7] = (uint8_t)(value >> 56U & 0xFF);
+
+	return efi_set_variable(name, vendor,
+				EFI_VARIABLE_BOOTSERVICE_ACCESS |
+				EFI_VARIABLE_RUNTIME_ACCESS, buf,
+				sizeof(buf));
+}
+
 struct efi_boot {
 	u32 attributes;
 	u16 file_path_len;
-- 
2.39.2

[PATCH 2/2] efi: fill more EFI runtime variables defined by systemd

[Michael Olbrich]

bootctl will use those variables if available, and produce somethink
like this:

System:
      Firmware: UEFI 2.70 (American Megatrends 5.13)
 Firmware Arch: x64
   Secure Boot: disabled (setup)
  TPM2 Support: firmware only, driver unavailable
  Boot into FW: supported

Current Boot Loader:
      Product: barebox-2023.11.0-dirty
     Features: ✗ Boot counting
               ✗ Menu timeout control
               ✗ One-shot menu timeout control
               ✗ Default entry control
               ✗ One-shot entry control
               ✗ Support for XBOOTLDR partition
               ✗ Support for passing random seed to OS
               ✗ Load drop-in drivers
               ✗ Support Type #1 sort-key field
               ✗ Support @saved pseudo-entry
               ✓ Support Type #1 devicetree field
               ✗ Enroll SecureBoot keys
               ✗ Retain SHIM protocols
               ✗ Boot loader sets ESP information
[...]

Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
---
 common/efi/payload/init.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/common/efi/payload/init.c b/common/efi/payload/init.c
index 19be7ff07fb6..cfacdffa6761 100644
--- a/common/efi/payload/init.c
+++ b/common/efi/payload/init.c
@@ -36,6 +36,7 @@
 #include <libfile.h>
 #include <state.h>
 #include <bbu.h>
+#include <generated/utsrelease.h>
 
 efi_runtime_services_t *RT;
 efi_boot_services_t *BS;
@@ -322,13 +323,46 @@ static int efi_core_init(void)
 }
 core_initcall(efi_core_init);
 
+/* Features of the loader, i.e. systemd-boot, barebox (imported from systemd) */
+#define EFI_LOADER_FEATURE_CONFIG_TIMEOUT          (1LL << 0)
+#define EFI_LOADER_FEATURE_CONFIG_TIMEOUT_ONE_SHOT (1LL << 1)
+#define EFI_LOADER_FEATURE_ENTRY_DEFAULT           (1LL << 2)
+#define EFI_LOADER_FEATURE_ENTRY_ONESHOT           (1LL << 3)
+#define EFI_LOADER_FEATURE_BOOT_COUNTING           (1LL << 4)
+#define EFI_LOADER_FEATURE_XBOOTLDR                (1LL << 5)
+#define EFI_LOADER_FEATURE_RANDOM_SEED             (1LL << 6)
+#define EFI_LOADER_FEATURE_LOAD_DRIVER             (1LL << 7)
+#define EFI_LOADER_FEATURE_SORT_KEY                (1LL << 8)
+#define EFI_LOADER_FEATURE_SAVED_ENTRY             (1LL << 9)
+#define EFI_LOADER_FEATURE_DEVICETREE              (1LL << 10)
+#define EFI_LOADER_FEATURE_SECUREBOOT_ENROLL       (1LL << 11)
+#define EFI_LOADER_FEATURE_RETAIN_SHIM             (1LL << 12)
+
+
 static int efi_postcore_init(void)
 {
 	char *uuid;
+	static const uint64_t loader_features =
+		EFI_LOADER_FEATURE_DEVICETREE;
 
 	efi_set_variable_usec("LoaderTimeInitUSec", &efi_systemd_vendor_guid,
 			      get_time_ns()/1000);
 
+	efi_set_variable_printf("LoaderInfo", &efi_systemd_vendor_guid,
+			"barebox-" UTS_RELEASE);
+
+	efi_set_variable_printf("LoaderFirmwareInfo", &efi_systemd_vendor_guid,
+				"%ls %u.%02u", efi_sys_table->fw_vendor,
+				efi_sys_table->fw_revision >> 16,
+				efi_sys_table->fw_revision & 0xffff);
+
+	efi_set_variable_printf("LoaderFirmwareType", &efi_systemd_vendor_guid,
+				"UEFI %u.%02u", efi_sys_table->hdr.revision >> 16,
+				efi_sys_table->hdr.revision & 0xffff);
+
+	efi_set_variable_uint64_le("LoaderFeatures", &efi_systemd_vendor_guid,
+				   loader_features);
+
 	uuid = device_path_to_partuuid(device_path_from_handle(
 				       efi_loaded_image->device_handle));
 	if (uuid) {
-- 
2.39.2

Re: [PATCH 1/2] efi: add more helper functions to write EFI variables

[Sascha Hauer]

On Wed, Dec 06, 2023 at 02:11:44PM +0100, Michael Olbrich wrote:
> Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
> ---
>  common/efi/payload/init.c | 38 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)

Applied, thanks

Sascha

> 
> diff --git a/common/efi/payload/init.c b/common/efi/payload/init.c
> index b990b54b2678..19be7ff07fb6 100644
> --- a/common/efi/payload/init.c
> +++ b/common/efi/payload/init.c
> @@ -107,6 +107,44 @@ int efi_set_variable_usec(char *name, efi_guid_t *vendor, uint64_t usec)
>  				(strlen(buf)+1) * sizeof(wchar_t));
>  }
>  
> +static int efi_set_variable_printf(char *name, efi_guid_t *vendor, const char *fmt, ...)
> +{
> +	va_list args;
> +	char *buf;
> +	wchar_t *buf16;
> +
> +	va_start(args, fmt);
> +	buf = xvasprintf(fmt, args);
> +	va_end(args);
> +	buf16 = xstrdup_char_to_wchar(buf);
> +
> +	return efi_set_variable(name, vendor,
> +				EFI_VARIABLE_BOOTSERVICE_ACCESS |
> +				EFI_VARIABLE_RUNTIME_ACCESS, buf16,
> +				(strlen(buf)+1) * sizeof(wchar_t));
> +	free(buf);
> +	free(buf16);
> +}
> +
> +static int efi_set_variable_uint64_le(char *name, efi_guid_t *vendor, uint64_t value)
> +{
> +	uint8_t buf[8];
> +
> +	buf[0] = (uint8_t)(value >> 0U & 0xFF);
> +	buf[1] = (uint8_t)(value >> 8U & 0xFF);
> +	buf[2] = (uint8_t)(value >> 16U & 0xFF);
> +	buf[3] = (uint8_t)(value >> 24U & 0xFF);
> +	buf[4] = (uint8_t)(value >> 32U & 0xFF);
> +	buf[5] = (uint8_t)(value >> 40U & 0xFF);
> +	buf[6] = (uint8_t)(value >> 48U & 0xFF);
> +	buf[7] = (uint8_t)(value >> 56U & 0xFF);
> +
> +	return efi_set_variable(name, vendor,
> +				EFI_VARIABLE_BOOTSERVICE_ACCESS |
> +				EFI_VARIABLE_RUNTIME_ACCESS, buf,
> +				sizeof(buf));
> +}
> +
>  struct efi_boot {
>  	u32 attributes;
>  	u16 file_path_len;
> -- 
> 2.39.2
> 
> 
> 

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