On Sat, 3 Apr 2021 09:03:32 +0200
Ahmad Fatoum <ahmad@xxxxxx> wrote:
Hi Ahmad!
I have just tested this patch on erizo FPGA. Barebox work fine.
--
Best regards,
Antony Pavlov
> Like on ARM, the PBL common code does not relocate the piggy data and
> instead keeps pointers into the old image's location.
>
> For relocate_to_current_adr, this doesn't matter, because both
> destination and source address are the same, but when running from ROM
> or flash relocate_to_adr will only copy up to __bss_start, so
> determining the piggy data bounds _must_ happen before relocation.
>
> We did so, but input_data_len, which references the image end was
> executed after relocation unearthing two bugs at once:
>
> - The compiler cached input_data_end from before relocation, so
> the runtime offset wasn't being added
>
> - Even with runtime offset added, we were pointing at the new
> address, but the old piggy data wasn't copied there (On erizo,
> it's still in ROM)
>
> Fix these by evaluating the bounds before relocation and add a comment,
> why it needs to be there. The same comment will also be added at the
> code's origin in the ARM architecture support.
>
> Reported-by: Antony Pavlov <antonynpavlov@xxxxxxxxx>
> Signed-off-by: Ahmad Fatoum <ahmad@xxxxxx>
> ---
> Please apply to master.
> ---
> arch/riscv/boot/uncompress.c | 6 +++---
> arch/riscv/include/asm/sections.h | 4 +++-
> 2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/arch/riscv/boot/uncompress.c b/arch/riscv/boot/uncompress.c
> index 411cefb0e31b..b4e010998a4a 100644
> --- a/arch/riscv/boot/uncompress.c
> +++ b/arch/riscv/boot/uncompress.c
> @@ -32,8 +32,11 @@ void __noreturn barebox_pbl_start(unsigned long membase, unsigned long memsize,
> void *pg_start, *pg_end;
> unsigned long pc = get_pc();
>
> + /* piggy data is not relocated, so determine the bounds now */
> pg_start = input_data + get_runtime_offset();
> pg_end = input_data_end + get_runtime_offset();
> + pg_len = pg_end - pg_start;
> + uncompressed_len = input_data_len();
>
> /*
> * If we run from inside the memory just relocate the binary
> @@ -45,9 +48,6 @@ void __noreturn barebox_pbl_start(unsigned long membase, unsigned long memsize,
> else
> relocate_to_adr(membase);
>
> - pg_len = pg_end - pg_start;
> - uncompressed_len = input_data_len();
> -
> barebox_base = riscv_mem_barebox_image(membase, endmem,
> uncompressed_len + MAX_BSS_SIZE);
>
> diff --git a/arch/riscv/include/asm/sections.h b/arch/riscv/include/asm/sections.h
> index 725fd8db474e..6673648bcd58 100644
> --- a/arch/riscv/include/asm/sections.h
> +++ b/arch/riscv/include/asm/sections.h
> @@ -15,9 +15,11 @@ extern char __dynsym_end[];
> extern char input_data[];
> extern char input_data_end[];
>
> +unsigned long get_runtime_offset(void);
> +
> static inline unsigned int input_data_len(void)
> {
> - return get_unaligned((const u32 *)(input_data_end - 4));
> + return get_unaligned((const u32 *)(input_data_end + get_runtime_offset() - 4));
> }
>
> #endif
> --
> 2.30.0
>
_______________________________________________
barebox mailing list
barebox@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/barebox
