Re: [U-Boot] [PATCH 7/9] [v3] lib/rsa: Add Kconfig option for HW accelerated RSA

29 Dec 2014

Hi Ruchika,
On 29 December 2014 at 00:05, Ruchika Gupta ruchika.gupta@freescale.com wrote:
...
Hi Simon,
...
-----Original Message-----
From: sjg@google.com [mailto:sjg@google.com] On Behalf Of Simon Glass
Sent: Wednesday, December 24, 2014 6:20 AM
To: Gupta Ruchika-R66431
Cc: U-Boot Mailing List; Sun York-R58495
Subject: Re: [PATCH 7/9] [v3] lib/rsa: Add Kconfig option for HW accelerated
RSA
Hi Ruchika,
On 23 December 2014 at 04:32, Ruchika Gupta ruchika.gupta@freescale.com
wrote:
...
Kconfig option added for devices which support RSA Verification
(Modular Exponentiation) operation in hardware
Signed-off-by: Ruchika Gupta ruchika.gupta@freescale.com
CC: Simon Glass sjg@chromium.org

Changes in v3:
New patch
lib/rsa/Kconfig | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)
I think this needs tweaking such that RSA_SW is a driver (use RSA_SOFTWARE
might be better).
For your freescale one, it should be RSA_FREESCALE_EXP or similar. We might
want to support multiple such devices. Don't use RSA_HW - that's not a
descriptive name.
If we are using driver Model, can multiple devices be selected at the same time for the RSA_UCLASS ? I am little confused.
Yes, they can be accessed using uclass_get_device_by_seq() if they are
numbered in the aliases:
aliases {
   mod_exp0 = "/path/to/hardware-node";
   mod_exp1 = "/path/to/software-node";
}
or uclass_get_device()  if there is no sequence numbering.
...
...
...

diff --git a/lib/rsa/Kconfig b/lib/rsa/Kconfig index 8f9aa44..fc8a1e7
100644
--- a/lib/rsa/Kconfig
+++ b/lib/rsa/Kconfig
@@ -11,7 +11,7 @@ if RSA && DM_RSA
config RSA_SW
        bool "User driver Model for RSA Modular Exponentiation in software"

  depends on DM && DM_RSA && RSA




  depends on DM && DM_RSA && RSA && !RSA_HW



You should drop the last term since it should be possible to have both
software and hardware.
This option selects the driver model for RSA software implementation suing RSA uclass. If I define both I get this error :
drivers/crypto/fsl/built-in.o:(.u_boot_list_2_driver_2_fsl_rsa+0x0): multiple definition of `_u_boot_list_2_driver_2_fsl_rsa'
drivers/crypto/rsa/built-in.o:(.u_boot_list_2_driver_2_fsl_rsa+0x0): first defined here
Make sure you use a different name  - it seems like you are using
fsl_rsa for both.
...
...
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    select RSA_MOD_EXP_SW
    default y
    help

@@ -20,6 +20,27 @@ config RSA_SW
          input.
          See doc/uImage.FIT/signature.txt for more details.
+menuconfig RSA_HW

  bool "Use crypto devices to implement RSA Modular Exponentiation"


  default y


  help


    Say Y here to get to see options for hardware crypto devices and


    processors. This option alone does not enable the crypto device.



    If you say N,all options in this submenu will be skipped and



disabled.
Space after N
...



+if RSA_HW



+config FSL_RSA

  bool "Implement RSA Modular Exponentiation with FSL crypto



accelerator"
...

  depends on DM && DM_RSA && RSA && FSL_CAAM


  default y


  help


    Enables driver for RSA modular exponentiation using Freescale's


    cryptographic accelerator - CAAM.




+endif



endif
config RSA_MOD_EXP_SW
1.8.1.4
Regards,
Simon

    