[Pdbg] [PATCH v3 06/25] libpdbg: Backend device tree cannot be overriden

[Alistair Popple]

Reviewed-by: Alistair Popple <alistair at popple.id.au>

On Friday, 17 April 2020 5:07:30 PM AEST Amitay Isaacs wrote:
> With drivers getting registered per backend, backend needs to be
> initialised before any device tree can be parsed.  PDBG_BACKEND_DTB
> allowed to override backend device tree without specifying backend,
> which cannot work any more.
> 
> To be able to dynamically update backend introduce PDBG_BACKEND and
> PDBG_BACKEND_OPTION variables instead of PDBG_BACKEND_DTB.
> 
> Signed-off-by: Amitay Isaacs <amitay at ozlabs.org>
> ---
>  libpdbg/dtb.c                     | 30 ++++++++++++++++++++++--------
>  tests/test_p9_fapi_translation.sh |  2 +-
>  2 files changed, 23 insertions(+), 9 deletions(-)
> 
> diff --git a/libpdbg/dtb.c b/libpdbg/dtb.c
> index ef51718..077bc62 100644
> --- a/libpdbg/dtb.c
> +++ b/libpdbg/dtb.c
> @@ -308,21 +308,36 @@ const char *pdbg_get_backend_option(void)
>  struct pdbg_dtb *pdbg_default_dtb(void *system_fdt)
>  {
>  	struct pdbg_dtb *dtb = &pdbg_dtb;
> -	const char *fdt;
> +	const char *fdt, *backend;
> 
>  	dtb->backend.fdt = NULL;
>  	dtb->system.fdt = system_fdt;
> 
> -	fdt = getenv("PDBG_BACKEND_DTB");
> -	if (fdt)
> -		mmap_dtb(fdt, false, &dtb->backend);
> -
>  	fdt = getenv("PDBG_DTB");
>  	if (fdt)
>  		mmap_dtb(fdt, false, &dtb->system);
> 
> -	if (dtb->backend.fdt && dtb->system.fdt)
> -		goto done;
> +	backend = getenv("PDBG_BACKEND");
> +	if (backend) {
> +		const char *arg;
> +
> +		arg = getenv("PDBG_BACKEND_OPTION");
> +
> +		if (!strcmp(backend, "fsi"))
> +			pdbg_set_backend(PDBG_BACKEND_FSI, arg);
> +		else if (!strcmp(backend, "i2c"))
> +			pdbg_set_backend(PDBG_BACKEND_I2C, arg);
> +		else if (!strcmp(backend, "kernel"))
> +			pdbg_set_backend(PDBG_BACKEND_KERNEL, arg);
> +		else if (!strcmp(backend, "fake"))
> +			pdbg_set_backend(PDBG_BACKEND_FAKE, arg);
> +		else if (!strcmp(backend, "host"))
> +			pdbg_set_backend(PDBG_BACKEND_HOST, arg);
> +		else if (!strcmp(backend, "cronus"))
> +			pdbg_set_backend(PDBG_BACKEND_CRONUS, arg);
> +		else
> +			pdbg_log(PDBG_ERROR, "Invalid backend '%s', ignoring\n", backend);
> +	}
> 
>  	if (!pdbg_backend)
>  		pdbg_backend = default_backend();
> @@ -412,7 +427,6 @@ struct pdbg_dtb *pdbg_default_dtb(void *system_fdt)
>  		break;
>  	}
> 
> -done:
>  	return dtb;
>  }
> 
> diff --git a/tests/test_p9_fapi_translation.sh
> b/tests/test_p9_fapi_translation.sh index a5a09b1..9891d39 100755
> --- a/tests/test_p9_fapi_translation.sh
> +++ b/tests/test_p9_fapi_translation.sh
> @@ -4,7 +4,7 @@
> 
>  test_group "p9 fapi translation tests"
> 
> -export PDBG_BACKEND_DTB=p9-kernel.dtb
> +export PDBG_BACKEND=kernel
>  export PDBG_DTB=p9.dtb
> 
>  test_result 0 <<EOF