[Skiboot] [PATCH 08/19] libstb/cvc.c: import softrom behavior from drivers/sw_driver.c

[Oliver]

On Sun, Nov 12, 2017 at 4:28 AM, Claudio Carvalho
<cclaudio at linux.vnet.ibm.com> wrote:
> Softrom is used only for testing with mambo. By setting
> compatible="ibm,secureboot-v1-softrom" in the "ibm,secureboot" node,
> firmware images can be properly measured even if the
> Container-Verification-Code (CVC) is not available. In this case, the
> mbedtls_sha512() function is used to calculate the sha512 hash of the
> firmware images.

If this is only used for testing in mambo why not build your own CVC
rom and load that into mambo? That way you can use the same interface
for sim and bare metal.

> This imports the softrom behavior from libstb/drivers/sw_driver.c code
> into cvc.c, but now softrom is implemented as a flag. When the flag is
> set, the wrappers for the CVC services work the same way as in
> sw_driver.c.
>
> Signed-off-by: Claudio Carvalho <cclaudio at linux.vnet.ibm.com>
> ---
>  libstb/cvc.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/libstb/cvc.c b/libstb/cvc.c
> index ddb6a1c..5f46e5e 100644
> --- a/libstb/cvc.c
> +++ b/libstb/cvc.c
> @@ -25,6 +25,7 @@
>  #include <xscom.h>
>  #include "container.h"
>  #include "cvc.h"
> +#include "mbedtls/sha512.h"
>
>  /*
>   * Assembly interfaces to call into the Container Verification Code.
> @@ -251,6 +252,15 @@ int call_cvc_sha512(const uint8_t *data, size_t data_len, uint8_t *digest,
>                 return OPAL_SUCCESS;
>
>         memset(digest, 0, SHA512_DIGEST_LENGTH);
> +       if (softrom) {
> +               mbedtls_sha512_context ctx;
> +               mbedtls_sha512_init(&ctx);
> +               mbedtls_sha512_starts(&ctx, 0); // SHA512 = 0
> +               mbedtls_sha512_update(&ctx, data, data_len);
> +               mbedtls_sha512_finish(&ctx, digest);
> +               mbedtls_sha512_free(&ctx);
> +               return OPAL_SUCCESS;
> +       }
>
>         service = cvc_find_service(CVC_SHA512_SERVICE);
>
> @@ -276,6 +286,9 @@ int call_cvc_verify(void *container, size_t len, const void *hw_key_hash,
>             !hw_key_hash || hw_key_hash_size <= 0)
>                 return OPAL_PARAMETER;
>
> +       if (softrom)
> +               return OPAL_RESOURCE;
> +
>         service = cvc_find_service(CVC_VERIFY_SERVICE);
>
>         if (!service)
> --
> 2.7.4
>
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