[PATCH v1] docs: Correct FW_JUMP_FDT_ADDR calculation example
Andrew Jones
ajones at ventanamicro.com
Thu Mar 23 10:18:00 PDT 2023
On Wed, Mar 22, 2023 at 01:04:48PM -0400, Gabriel Somlo wrote:
> When using `PLATFORM=generic` defaults, the kernel is loaded at
> `FW_JUMP_ADDR = FW_TEXT_START + 0x200000`, and the FDT is loaded at
> `FW_JUMP_FDT_ADDR = FW_TEXT_START + 0x2200000`.
>
> Therefore, the maximum kernel size before `FW_JUMP_FDT_ADDR` must
> be increased is the difference, or `0x2000000`.
Sounds good, but this is only correct for RV64. For RV32 it should be
0x1e00000. I wonder if we should do something like
```
${CROSS_COMPILE}objdump -h $KERNEL_ELF | sort -k 5,5 | awk -n '/^ +[0-9]+ /\
{addr="0x"$3; size="0x"$5; printf "0x""%x\n",addr+size}' \
- | (( `tail -1` > 0x2200000 )) && echo fdt overlaps kernel,\
- increase FW_JUMP_FDT_ADDR
+ | (( `tail -1` > (FW_JUMP_FDT_ADDR - FW_JUMP_ADDR) )) && echo fdt overlaps \
+ kernel, increase FW_JUMP_FDT_ADDR
${LLVM}objdump -h --show-lma $KERNEL_ELF | sort -k 5,5 | \
awk -n '/^ +[0-9]+ / {addr="0x"$3; size="0x"$5; printf "0x""%x\n",addr+size}'\
- | (( `tail -1` > 0x2200000 )) && echo fdt overlaps kernel,\
- increase FW_JUMP_FDT_ADDR
+ | (( `tail -1` > (FW_JUMP_FDT_ADDR - FW_JUMP_ADDR) )) && echo fdt overlaps \
+ kernel, increase FW_JUMP_FDT_ADDR
```
instead?
Thanks,
drew
>
> Update the example calculation to reflect this, and avoid confusion.
>
> Signed-off-by: Gabriel Somlo <gsomlo at gmail.com>
> ---
> docs/firmware/fw_jump.md | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/docs/firmware/fw_jump.md b/docs/firmware/fw_jump.md
> index 956897e..d1b07b9 100644
> --- a/docs/firmware/fw_jump.md
> +++ b/docs/firmware/fw_jump.md
> @@ -48,12 +48,12 @@ follows:
> ```
> ${CROSS_COMPILE}objdump -h $KERNEL_ELF | sort -k 5,5 | awk -n '/^ +[0-9]+ /\
> {addr="0x"$3; size="0x"$5; printf "0x""%x\n",addr+size}' \
> - | (( `tail -1` > 0x2200000 )) && echo fdt overlaps kernel,\
> + | (( `tail -1` > 0x2000000 )) && echo fdt overlaps kernel,\
> increase FW_JUMP_FDT_ADDR
>
> ${LLVM}objdump -h --show-lma $KERNEL_ELF | sort -k 5,5 | \
> awk -n '/^ +[0-9]+ / {addr="0x"$3; size="0x"$5; printf "0x""%x\n",addr+size}'\
> - | (( `tail -1` > 0x2200000 )) && echo fdt overlaps kernel,\
> + | (( `tail -1` > 0x2000000 )) && echo fdt overlaps kernel,\
> increase FW_JUMP_FDT_ADDR
> ```
>
> --
> 2.39.2
>
>
> --
> opensbi mailing list
> opensbi at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/opensbi
More information about the opensbi
mailing list