[PATCH v7 1/4] efi: Introduce EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER and corresponding structures

[PATCH v7 1/4] efi: Introduce EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER and corresponding structures

[Chen Yu]

Platform Firmware Runtime Update image starts with UEFI headers, and the
headers are defined in UEFI specification, but some of them have not been
defined in the kernel yet.

For example, the header layout of a capsule file looks like this:

EFI_CAPSULE_HEADER
EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER
EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER
EFI_FIRMWARE_IMAGE_AUTHENTICATION

These structures would be used by the Platform Firmware Runtime Update
driver to parse the format of capsule file to verify if the corresponding
version number is valid. The EFI_CAPSULE_HEADER has been defined in the
kernel, however the rest are not, thus introduce corresponding UEFI
structures accordingly. Besides, EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER
and EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER are required to be packed
in the uefi specification. And Ard has pointed out that, the __packed
attribute does indicate to the compiler that the entire thing can appear
misaligned in memory. So if one follows the other in the capsule header,
the __packed attribute may be appropriate to ensure that the second one
is not accessed using misaligned loads and stores.

Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
v7: Use __packed instead of pragma pack(1). (Greg Kroah-Hartman, Ard Biesheuve) 
v6: No change since v5.
v5: No change since v4.
v4: Revise the commit log to make it more clear. (Rafael J. Wysocki) 
---
 include/linux/efi.h | 46 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/include/linux/efi.h b/include/linux/efi.h
index 6b5d36babfcc..f4acdb52cdfb 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -148,6 +148,52 @@ typedef struct {
 	u32 imagesize;
 } efi_capsule_header_t;
 
+/* EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER */
+struct efi_manage_capsule_header {
+	u32	ver;
+	u16	emb_drv_cnt;
+	u16	payload_cnt;
+	/*
+	 * Variable array indicated by number of
+	 * (emb_drv_cnt + payload_cnt)
+	 */
+	u64	offset_list[];
+} __packed;
+
+/* EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER */
+struct efi_manage_capsule_image_header {
+	u32	ver;
+	guid_t	image_type_id;
+	u8	image_index;
+	u8	reserved_bytes[3];
+	u32	image_size;
+	u32	vendor_code_size;
+	/* ver = 2. */
+	u64	hw_ins;
+	/* ver = v3. */
+	u64	capsule_support;
+} __packed;
+
+/* WIN_CERTIFICATE */
+struct win_cert {
+	u32	len;
+	u16	rev;
+	u16	cert_type;
+};
+
+/* WIN_CERTIFICATE_UEFI_GUID */
+struct win_cert_uefi_guid {
+	struct win_cert	hdr;
+	guid_t		cert_type;
+	u8		cert_data[];
+};
+
+/* EFI_FIRMWARE_IMAGE_AUTHENTICATIO */
+struct efi_image_auth {
+	u64				mon_count;
+	struct win_cert_uefi_guid	auth_info;
+};
+
 /*
  * EFI capsule flags
  */
-- 
2.25.1

Re: [PATCH v7 1/4] efi: Introduce EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER and corresponding structures

[Andy Shevchenko]

On Wed, Oct 27, 2021 at 03:07:24PM +0800, Chen Yu wrote:
> Platform Firmware Runtime Update image starts with UEFI headers, and the
> headers are defined in UEFI specification, but some of them have not been
> defined in the kernel yet.
> 
> For example, the header layout of a capsule file looks like this:
> 
> EFI_CAPSULE_HEADER
> EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER
> EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER
> EFI_FIRMWARE_IMAGE_AUTHENTICATION
> 
> These structures would be used by the Platform Firmware Runtime Update
> driver to parse the format of capsule file to verify if the corresponding
> version number is valid. The EFI_CAPSULE_HEADER has been defined in the
> kernel, however the rest are not, thus introduce corresponding UEFI
> structures accordingly. Besides, EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER
> and EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER are required to be packed
> in the uefi specification. And Ard has pointed out that, the __packed
> attribute does indicate to the compiler that the entire thing can appear
> misaligned in memory. So if one follows the other in the capsule header,
> the __packed attribute may be appropriate to ensure that the second one
> is not accessed using misaligned loads and stores.

...

> +/* EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER */
> +struct efi_manage_capsule_image_header {
> +	u32	ver;

> +	guid_t	image_type_id;

Shouldn't it be efi_guid_t ?

> +	u8	image_index;
> +	u8	reserved_bytes[3];
> +	u32	image_size;
> +	u32	vendor_code_size;
> +	/* ver = 2. */
> +	u64	hw_ins;
> +	/* ver = v3. */
> +	u64	capsule_support;
> +} __packed;

...

> +/* WIN_CERTIFICATE_UEFI_GUID */
> +struct win_cert_uefi_guid {
> +	struct win_cert	hdr;

> +	guid_t		cert_type;

Ditto.

> +	u8		cert_data[];
> +};

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v7 1/4] efi: Introduce EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER and corresponding structures

[Chen Yu]

On Wed, Oct 27, 2021 at 01:00:43PM +0300, Andy Shevchenko wrote:
> On Wed, Oct 27, 2021 at 03:07:24PM +0800, Chen Yu wrote:
> > Platform Firmware Runtime Update image starts with UEFI headers, and the
> > headers are defined in UEFI specification, but some of them have not been
> > defined in the kernel yet.
> > 
> > For example, the header layout of a capsule file looks like this:
> > 
> > EFI_CAPSULE_HEADER
> > EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER
> > EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER
> > EFI_FIRMWARE_IMAGE_AUTHENTICATION
> > 
> > These structures would be used by the Platform Firmware Runtime Update
> > driver to parse the format of capsule file to verify if the corresponding
> > version number is valid. The EFI_CAPSULE_HEADER has been defined in the
> > kernel, however the rest are not, thus introduce corresponding UEFI
> > structures accordingly. Besides, EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER
> > and EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER are required to be packed
> > in the uefi specification. And Ard has pointed out that, the __packed
> > attribute does indicate to the compiler that the entire thing can appear
> > misaligned in memory. So if one follows the other in the capsule header,
> > the __packed attribute may be appropriate to ensure that the second one
> > is not accessed using misaligned loads and stores.
> 
> ...
> 
> > +/* EFI_FIRMWARE_MANAGEMENT_CAPSULE_IMAGE_HEADER */
> > +struct efi_manage_capsule_image_header {
> > +	u32	ver;
> 
> > +	guid_t	image_type_id;
> 
> Shouldn't it be efi_guid_t ?
>
I see, will change it, also in other patches.

thanks,
Chenyu