[U-Boot] [RFC 5/9] arm: omap5: add secure ROM signature verify API

[Simon Glass]

On 15 June 2016 at 13:26, Andreas Dannenberg <dannenberg at ti.com> wrote:
> From: Daniel Allred <d-allred at ti.com>
>
> Adds an API that verifies a signature attached to an image (binary
> blob). This API is basically a entry to a secure ROM service provided by
> the device and accessed via an SMC call, using a particular calling
> convention.
>
> Signed-off-by: Daniel Allred <d-allred at ti.com>
> Signed-off-by: Andreas Dannenberg <dannenberg at ti.com>
> ---
>  arch/arm/cpu/armv7/omap5/Makefile           |  1 +
>  arch/arm/cpu/armv7/omap5/sec_fxns.c         | 70 +++++++++++++++++++++++++++++
>  arch/arm/include/asm/arch-omap5/sys_proto.h |  4 ++
>  3 files changed, 75 insertions(+)
>  create mode 100644 arch/arm/cpu/armv7/omap5/sec_fxns.c

Reviewed-by: Simon Glass <sjg at chromium.org>

Please see below.

>
> diff --git a/arch/arm/cpu/armv7/omap5/Makefile b/arch/arm/cpu/armv7/omap5/Makefile
> index 3caba86..d373bf4 100644
> --- a/arch/arm/cpu/armv7/omap5/Makefile
> +++ b/arch/arm/cpu/armv7/omap5/Makefile
> @@ -14,3 +14,4 @@ obj-y += hw_data.o
>  obj-y  += abb.o
>  obj-y  += fdt.o
>  obj-$(CONFIG_IODELAY_RECALIBRATION) += dra7xx_iodelay.o
> +obj-$(CONFIG_TI_SECURE_DEVICE) += sec_fxns.o
> diff --git a/arch/arm/cpu/armv7/omap5/sec_fxns.c b/arch/arm/cpu/armv7/omap5/sec_fxns.c
> new file mode 100644
> index 0000000..766333a
> --- /dev/null
> +++ b/arch/arm/cpu/armv7/omap5/sec_fxns.c
> @@ -0,0 +1,70 @@
> +/*
> + *
> + * Common security functions that rely on secure ROM services
> + *
> + * (C) Copyright 2016
> + * Texas Instruments, <www.ti.com>
> + *
> + * Daniel Allred    <d-allred at ti.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <asm/arch/sys_proto.h>
> +#include <asm/omap_common.h>
> +
> +#define SIGNATURE_LENGTH                               (0x118)
> +
> +/* API Index for OMAP5, DRA7xx */
> +#define API_HAL_KM_VERIFYCERTIFICATESIGNATURE_INDEX    (0x0000000E)
> +
> +int secure_boot_verify_image(void **image, size_t *size)
> +{
> +       int result = 1;
> +       u32 cert_addr, sig_addr;
> +       size_t cert_size;
> +
> +#ifndef CONFIG_SYS_DCACHE_OFF
> +       /* Perform cache writeback on input buffer */
> +       flush_dcache_range(
> +               (u32)*image,
> +               (u32)*image + roundup(*size, ARCH_DMA_MINALIGN));
> +#endif
> +       cert_addr = (uint32_t)*image;
> +       *size -= SIGNATURE_LENGTH;   /* Subtract out the signature size */
> +       cert_size = *size;
> +       sig_addr = cert_addr + cert_size;
> +
> +       /* Check if image load address is 32-bit aligned */
> +       if (0 != (0x3 & cert_addr)) {
> +               puts("Image is not 4-byte aligned.\n");
> +               result = 1;
> +               goto auth_exit;
> +       }
> +
> +       /* Image size also should be multiple of 4 */
> +       if (0 != (0x3 & cert_size)) {
> +               puts("Image size is not 4-byte aligned.\n");
> +               result = 1;
> +               goto auth_exit;
> +       }
> +
> +       /* Call ROM HAL API to verify certificate signature */
> +       debug("%s: load_addr = %x, size = %x, sig_addr = %x\n", __func__,
> +             cert_addr, cert_size, sig_addr);
> +
> +       result = secure_rom_call(
> +               API_HAL_KM_VERIFYCERTIFICATESIGNATURE_INDEX, 0, 0,
> +               4, cert_addr, cert_size, sig_addr, 0xFFFFFFFF);
> +auth_exit:
> +       if (result != 0) {
> +               puts("Authentication failed!\n");
> +               printf("Return Value = %08X\n", result);
> +               hang();
> +       }
> +
> +       printf("Authentication passed: %s\n", (char *)sig_addr);
> +
> +       return result;
> +}
> diff --git a/arch/arm/include/asm/arch-omap5/sys_proto.h b/arch/arm/include/asm/arch-omap5/sys_proto.h
> index ab0e7fa..b175124 100644
> --- a/arch/arm/include/asm/arch-omap5/sys_proto.h
> +++ b/arch/arm/include/asm/arch-omap5/sys_proto.h
> @@ -84,4 +84,8 @@ static inline u32 usec_to_32k(u32 usec)
>  #define OMAP5_SERVICE_L2ACTLR_SET    0x104
>  #define OMAP5_SERVICE_ACR_SET        0x107
>
> +#ifdef CONFIG_TI_SECURE_DEVICE
> +int secure_boot_verify_image(void **p_image, size_t *p_size);

Function comment please.

> +#endif
> +
>  #endif
> --
> 2.6.4
>