[PATCH] firmware: Bring back FW_TEXT_START as an optional parameter

[Anup Patel]

On Wed, May 15, 2024 at 11:57 AM Anup Patel <apatel at ventanamicro.com> wrote:
>
> Bring back FW_TEXT_START as an optional parameter to allow users
> explicitly specify compile time address for loading debug symbols.
> When not specified, the FW_TEXT_START is assumed to be 0.
>
> Fixes: d4d2582eef7a ("firmware: remove FW_TEXT_START")
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>

Applied this patch to the riscv/opensbi repo.

Regards,
Anup

> ---
>  docs/firmware/fw.md            | 3 +++
>  firmware/fw_base.S             | 4 +++-
>  firmware/fw_base.ldS           | 3 ++-
>  firmware/fw_payload.elf.ldS    | 2 +-
>  firmware/objects.mk            | 6 ++++++
>  firmware/payloads/test.elf.ldS | 2 +-
>  6 files changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/docs/firmware/fw.md b/docs/firmware/fw.md
> index 3cc0262..d298096 100644
> --- a/docs/firmware/fw.md
> +++ b/docs/firmware/fw.md
> @@ -61,6 +61,9 @@ Firmware Configuration and Compilation
>  All firmware types support the following common compile time configuration
>  parameters:
>
> +* **FW_TEXT_START** - Defines the compile time address of the OpenSBI
> +  firmware. This configuration parameter is optional and assumed to be
> +  `0` if not specified.
>  * **FW_FDT_PATH** - Path to an external flattened device tree binary file to
>    be embedded in the *.rodata* section of the final firmware. If this option
>    is not provided then the firmware will expect the FDT to be passed as an
> diff --git a/firmware/fw_base.S b/firmware/fw_base.S
> index 9f995a2..b950c0b 100644
> --- a/firmware/fw_base.S
> +++ b/firmware/fw_base.S
> @@ -53,7 +53,9 @@ _try_lottery:
>         bnez    a6, _wait_for_boot_hart
>
>         /* relocate the global table content */
> -       lla     t2, _fw_start
> +       li      t0, FW_TEXT_START       /* link start */
> +       lla     t1, _fw_start           /* load start */
> +       sub     t2, t1, t0              /* load offset */
>         lla     t0, __rel_dyn_start
>         lla     t1, __rel_dyn_end
>         beq     t0, t1, _relocate_done
> diff --git a/firmware/fw_base.ldS b/firmware/fw_base.ldS
> index 9d11db5..fb47984 100644
> --- a/firmware/fw_base.ldS
> +++ b/firmware/fw_base.ldS
> @@ -7,7 +7,8 @@
>   *   Anup Patel <anup.patel at wdc.com>
>   */
>
> -       /* Don't add any section before _fw_start */
> +       . = FW_TEXT_START;
> +       /* Don't add any section between FW_TEXT_START and _fw_start */
>         PROVIDE(_fw_start = .);
>
>         . = ALIGN(0x1000); /* Need this to create proper sections */
> diff --git a/firmware/fw_payload.elf.ldS b/firmware/fw_payload.elf.ldS
> index 94e1ac6..f1a544b 100644
> --- a/firmware/fw_payload.elf.ldS
> +++ b/firmware/fw_payload.elf.ldS
> @@ -15,7 +15,7 @@ SECTIONS
>         #include "fw_base.ldS"
>
>  #ifdef FW_PAYLOAD_OFFSET
> -       . = FW_PAYLOAD_OFFSET;
> +       . = FW_TEXT_START + FW_PAYLOAD_OFFSET;
>  #else
>         . = ALIGN(FW_PAYLOAD_ALIGN);
>  #endif
> diff --git a/firmware/objects.mk b/firmware/objects.mk
> index a51ff65..a90485d 100644
> --- a/firmware/objects.mk
> +++ b/firmware/objects.mk
> @@ -13,6 +13,12 @@ firmware-cflags-y +=
>  firmware-asflags-y +=
>  firmware-ldflags-y +=
>
> +ifdef FW_TEXT_START
> +firmware-genflags-y += -DFW_TEXT_START=$(FW_TEXT_START)
> +else
> +firmware-genflags-y += -DFW_TEXT_START=0x0
> +endif
> +
>  ifdef FW_FDT_PATH
>  firmware-genflags-y += -DFW_FDT_PATH=\"$(FW_FDT_PATH)\"
>  ifdef FW_FDT_PADDING
> diff --git a/firmware/payloads/test.elf.ldS b/firmware/payloads/test.elf.ldS
> index 08e008f..2328a1b 100644
> --- a/firmware/payloads/test.elf.ldS
> +++ b/firmware/payloads/test.elf.ldS
> @@ -13,7 +13,7 @@ ENTRY(_start)
>  SECTIONS
>  {
>  #ifdef FW_PAYLOAD_OFFSET
> -       . = FW_PAYLOAD_OFFSET;
> +       . = FW_TEXT_START + FW_PAYLOAD_OFFSET;
>  #else
>         . = ALIGN(FW_PAYLOAD_ALIGN);
>  #endif
> --
> 2.34.1
>