[U-Boot] [PATCH v4 02/16] efi: Update some comments related to smbios tables

[Heinrich Schuchardt <xypron.glpk@gmx.de>]

On 05/16/2018 05:42 PM, Simon Glass wrote:
> Clarify the operation of this code with some additional comments.
> 
> Signed-off-by: Simon Glass <sjg@chromium.org>

Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

> ---
> 
> Changes in v4:
> - Remove code already applied
> - Update subject
> 
> Changes in v3:
> - Add comments on aligment
> - Return error value of efi_allocate_pages()
> - Update function comment for write_smbios_table()
> 
> Changes in v2:
> - Update return type of efi_smbios_register() to efi_status_t
> - Use return value of efi_install_configuration_table
> 
>  include/efi_loader.h        | 7 +++++++
>  include/smbios.h            | 5 +++--
>  lib/efi_loader/efi_smbios.c | 7 ++++++-
>  3 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 2868ca25abb..2519a7c33a7 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -207,6 +207,13 @@ efi_status_t efi_net_register(void);
>  /* Called by bootefi to make the watchdog available */
>  efi_status_t efi_watchdog_register(void);
>  /* Called by bootefi to make SMBIOS tables available */
> +/**
> + * efi_smbios_register() - write out SMBIOS tables
> + *
> + * Called by bootefi to make SMBIOS tables available
> + *
> + * @return 0 if OK, -ENOMEM if no memory is available for the tables
> + */
>  efi_status_t efi_smbios_register(void);
>  
>  struct efi_simple_file_system_protocol *
> diff --git a/include/smbios.h b/include/smbios.h
> index 79880ef5b5c..97b9ddce237 100644
> --- a/include/smbios.h
> +++ b/include/smbios.h
> @@ -231,8 +231,9 @@ typedef int (*smbios_write_type)(ulong *addr, int handle);
>   *
>   * This writes SMBIOS table at a given address.
>   *
> - * @addr:	start address to write SMBIOS table
> - * @return:	end address of SMBIOS table
> + * @addr:	start address to write SMBIOS table. If this is not
> + *	16-byte-aligned then it will be aligned before the table is written
> + * @return:	end address of SMBIOS table (and start address for next entry)
>   */
>  ulong write_smbios_table(ulong addr);
>  
> diff --git a/lib/efi_loader/efi_smbios.c b/lib/efi_loader/efi_smbios.c
> index 482436e2adb..7c3fc8af0b2 100644
> --- a/lib/efi_loader/efi_smbios.c
> +++ b/lib/efi_loader/efi_smbios.c
> @@ -29,7 +29,12 @@ efi_status_t efi_smbios_register(void)
>  	if (ret != EFI_SUCCESS)
>  		return ret;
>  
> -	/* Generate SMBIOS tables */
> +	/*
> +	 * Generate SMBIOS tables - we know that efi_allocate_pages() returns
> +	 * a 4k-aligned address, so it is safe to assume that
> +	 * write_smbios_table() will write the table at that address.
> +	 */
> +	assert(!(dmi & 0xf));
>  	write_smbios_table(dmi);
>  
>  	/* And expose them to our EFI payload */
>