On Sat, 28 Mar 2026 at 08:44, Marek Vasut <[email protected]> wrote: > > On 3/27/26 1:23 PM, Ilias Apalodimas wrote: > > Hello Ilias, > > >>> Add a Kconfig option and allow the common code to relocate U-Boot > >>> to the top of the last discovered bank. > >> > >> The commit message should really clarify the current pitfalls of > >> enabling this symbol, including the part where ethernet transfers above > >> 4 GiB used to work because of the packet buffer built into U-Boot, and > >> they will break because the buffer is now relocated above 4 GiB too. > > > > Shall I just add your note from the RFC with a few adjustments? I.e > > > > NOTE: This currently might break platforms. If the ethernet > > controller cannot DMA above 4 GiB, and once U-Boot does > > get relocated above 4 GiB, the packet buffer which is built > > into the U-Boot binary is also relocated above 4 GiB. > > This patch should not be applied in the first place, this DOES break > things. I think when this patch is safe to be applied, the note will not > be needed.
The patch obviously will not get applied. I was referring to the note in the commit message only. I'll just add it with slight changes in the commit > > [...] > >>> +++ b/common/board_f.c > >>> @@ -321,6 +321,8 @@ __weak phys_addr_t > >>> board_get_usable_ram_top(phys_size_t total_size) > >>> */ > >>> return 0; > >>> #endif > >>> + if (IS_ENABLED(CONFIG_RELOCATE_LAST_BANK)) > >>> + fdtdec_setup_mem_ram_top(); > >> Return value may need checking ? > > > > sure, but should we panic ? Or print a message and silently keep the > > old reloc address? > Print a message and relocate below 4 GiB , for maximum compatibility maybe ? Yea that's what I currently have on my local branch Cheers /Ilias
