Hi Ilias, On 2026-06-04T07:37:05, Ilias Apalodimas <[email protected]> wrote: > doc: Add a warning about using RELOC_ADDR_TOP > > Since devices that can't DMA above 4GiB will misbehave with this option > enabled add a warning on the documentation. > > Signed-off-by: Ilias Apalodimas <[email protected]> > > doc/develop/memory.rst | 6 ++++++ > 1 file changed, 6 insertions(+)
Reviewed-by: Simon Glass <[email protected]> nits/suggestions below > diff --git a/doc/develop/memory.rst b/doc/develop/memory.rst > @@ -110,6 +110,12 @@ U-Boot Proper Flow > > This follows the same as in SPL flow. In board_init_f(), a part of > memory > is reserved at the end of RAM (see reserve_* functions in > init_sequence_f) > + #. Relocation address > + By default U-Boot will try to relocate below the 4GiB boundary. If > + RELOC_ADDR_TOP is enabled U-Boot will look into the dram bank config of > + gd->dram[] and try to relocate to the highest available bank. Use this > + with caution as devices that can only DMA below 4GiB will misbehave > + since their buffers may be allocated above the 32-bit boundary. Can you check the rendering here? It seems that the title will run on to the text? Also text only covers the default and RELOC_ADDR_TOP, but does not mention that boards can still override via board_get_usable_ram_top(). Worth a sentence, since that is the other half of the new behaviour from patch 5. Regards, Simon
