Simon, could you review this patch? If not, who can do it?
On Sunday 28 August 2022 17:19:29 Marek Behún wrote:
From: Pali Rohár pali@kernel.org
When U-Boot is running from flash memory (execute in place) then gd->fdt_blob before relocation points to read-only flash memory.
So U-Boot calls board_fix_fdt() with read-only gd->fdt_blob pointer which cause immediate CPU crash when callback is trying to modify gd->fdt_blob.
Fix this issue by introducing a new config option OF_DTB_READONLY_BEFORE_RELOC which moves fix_fdt callback after the reloc_fdt callback. This makes CONFIG_OF_BOARD_FIXUP working also if U-Boot before relocation is not running from read/write (S)RAM memory.
This is required for mpc85xx boards when booting from flash NOR.
Signed-off-by: Pali Rohár pali@kernel.org Signed-off-by: Marek Behún kabel@kernel.org
Changes since v1:
- just changed the new Kconfig option name and associated help string
common/board_f.c | 8 +++++++- dts/Kconfig | 6 ++++++ 2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/common/board_f.c b/common/board_f.c index 18e2246733..35fb4a0753 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -911,7 +911,7 @@ static const init_fnc_t init_sequence_f[] = { * - board info struct */ setup_dest_addr, -#ifdef CONFIG_OF_BOARD_FIXUP +#if defined(CONFIG_OF_BOARD_FIXUP) && !defined(CONFIG_OF_DTB_READONLY_BEFORE_RELOC) fix_fdt, #endif #ifdef CONFIG_PRAM @@ -926,6 +926,10 @@ static const init_fnc_t init_sequence_f[] = { reserve_board, reserve_global_data, reserve_fdt, +#if defined(CONFIG_OF_BOARD_FIXUP) && defined(CONFIG_OF_DTB_READONLY_BEFORE_RELOC)
- reloc_fdt,
- fix_fdt,
+#endif reserve_bootstage, reserve_bloblist, reserve_arch, @@ -936,7 +940,9 @@ static const init_fnc_t init_sequence_f[] = { setup_bdinfo, display_new_sp, INIT_FUNC_WATCHDOG_RESET +#if !defined(CONFIG_OF_BOARD_FIXUP) || !defined(CONFIG_OF_DTB_READONLY_BEFORE_RELOC) reloc_fdt, +#endif reloc_bootstage, reloc_bloblist, setup_reloc, diff --git a/dts/Kconfig b/dts/Kconfig index bc5f22029f..29e5248b15 100644 --- a/dts/Kconfig +++ b/dts/Kconfig @@ -105,6 +105,12 @@ config OF_EMBED
endchoice
+config OF_DTB_READONLY_BEFORE_RELOC
- bool "Initial DTB (before relocation) for DT control is read-only"
- help
If initial (before relocation) DTB for DT control is read-only,(e.g. points to memory-mapped flash memory), set this option.config OF_BOARD bool "Provided by the board (e.g a previous loader) at runtime" default y if SANDBOX || OF_HAS_PRIOR_STAGE -- 2.35.1