Re: [PATCH v2 4/5] ieee1275/tcg2: Add TCG2 driver for ieee1275 PowerPC firmware

[Daniel Kiper]

On Mon, Nov 25, 2024 at 05:41:41PM -0500, Stefan Berger wrote:
> Follow recent extensions of EFI support providing a TCG2 driver with a
> public API for getting the maximum TPM command size and passing a TPM
> command through to the TPM 2. Implement this functionality using
> ieee1275 PowerPC firmware API calls. Convert the tcg2 driver code now
> to a built-in driver.

The "built-in driver" phrase should not be used in that context.
I explained it in the patch #2.

> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> ---
>  grub-core/Makefile.core.def   |   3 +-
>  grub-core/lib/ieee1275/tcg2.c | 104 ++++++++++++++++++++++++++++++++++
>  2 files changed, 106 insertions(+), 1 deletion(-)
>
> diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
> index c5fd796d4..8ecedf986 100644
> --- a/grub-core/Makefile.core.def
> +++ b/grub-core/Makefile.core.def
> @@ -1155,7 +1155,6 @@ module = {
>    name = tpm;
>    common = commands/tpm.c;
>    ieee1275 = commands/ieee1275/ibmvtpm.c;
> -  ieee1275 = lib/ieee1275/tcg2.c;
>    enable = powerpc_ieee1275;
>  };
>
> @@ -2576,8 +2575,10 @@ module = {
>    common = lib/tss2/tss2.c;
>    efi = lib/efi/tcg2.c;
>    emu = lib/tss2/tcg2_emu.c;
> +  powerpc_ieee1275 = lib/ieee1275/tcg2.c;
>    enable = efi;
>    enable = emu;
> +  enable = powerpc_ieee1275;
>    cppflags = '-I$(srcdir)/lib/tss2';
>  };
>
> diff --git a/grub-core/lib/ieee1275/tcg2.c b/grub-core/lib/ieee1275/tcg2.c
> index 8f29b3c1e..63ef34fcd 100644
> --- a/grub-core/lib/ieee1275/tcg2.c
> +++ b/grub-core/lib/ieee1275/tcg2.c
> @@ -23,6 +23,8 @@
>  #include <grub/mm.h>
>  #include <grub/misc.h>
>
> +#include <tcg2.h>
> +
>  grub_ieee1275_ihandle_t grub_ieee1275_tpm_ihandle = IEEE1275_IHANDLE_INVALID;
>
>  grub_err_t
> @@ -50,3 +52,105 @@ grub_ieee1275_tpm_init (void)
>
>    return GRUB_ERR_NONE;
>  }
> +
> +grub_err_t
> +grub_tcg2_get_max_output_size (grub_size_t *size)
> +{
> +  struct tpm_get_maximum_cmd_size
> +  {
> +    struct grub_ieee1275_common_hdr common;
> +    grub_ieee1275_cell_t method;
> +    grub_ieee1275_cell_t ihandle;
> +    grub_ieee1275_cell_t catch_result;
> +    grub_ieee1275_cell_t size;
> +  };
> +  struct tpm_get_maximum_cmd_size args;
> +  static int error_displayed = 0;

Bool please...

> +  grub_err_t err;
> +
> +  err = grub_ieee1275_tpm_init ();
> +  if (err != GRUB_ERR_NONE)
> +      return err;
> +
> +  INIT_IEEE1275_COMMON (&args.common, "call-method", 2, 2);
> +  args.method = (grub_ieee1275_cell_t) "get-maximum-cmd-size";
> +  args.ihandle = grub_ieee1275_tpm_ihandle;
> +
> +  if (IEEE1275_CALL_ENTRY_FN (&args) == -1)
> +    return GRUB_ERR_INVALID_COMMAND;
> +
> +  /*
> +   * catch_result is set if firmware does not support get-maximum-cmd-size
> +   * rc is GRUB_IEEE1275_CELL_FALSE (0) on failure
> +   */
> +  if (args.catch_result)
> +    {
> +      if (!error_displayed)
> +     {
> +       error_displayed++;
> +       return grub_error (GRUB_ERR_BAD_DEVICE,
> +                          "get-maximum-cmd-size failed: Firmware is likely 
> too old.\n");
> +     }
> +      return GRUB_ERR_INVALID_COMMAND;
> +    }
> +
> +  *size = args.size;
> +
> +  return GRUB_ERR_NONE;
> +}
> +
> +grub_err_t
> +grub_tcg2_submit_command (grub_size_t input_size,
> +                       grub_uint8_t *input,
> +                       grub_size_t output_size,
> +                       grub_uint8_t *output)
> +{
> +  struct tpm_pass_through_to_tpm
> +  {
> +    struct grub_ieee1275_common_hdr common;
> +    grub_ieee1275_cell_t method;
> +    grub_ieee1275_cell_t ihandle;
> +    grub_ieee1275_cell_t buf_size;
> +    grub_ieee1275_cell_t buf_addr;
> +    grub_ieee1275_cell_t catch_result;
> +    grub_ieee1275_cell_t resp_size;
> +  };
> +  struct tpm_pass_through_to_tpm args;
> +  static int error_displayed = 0;

Ditto...

Daniel