According to README CFG_SYS_BOOTMAPSZ section, in case both "bootm_low" and "bootm_size" variables are defined, "bootm_mapsize" variable is not defined and CFG_SYS_BOOTMAPSZ macro is not defined, all data for the Linux kernel must be between "bootm_low" and "bootm_low" + "bootm_size".
Currently, for systems with DRAM between 0x4000_0000..0x7fff_ffff and with e.g. bootm_low=0x60000000 and bootm_size=0x10000000, the code will attempt to reserve memory from 0x4000_0000..0x4fff_ffff, which is incorrect. This is because "bootm_low" is not taken into consideration correctly. The last parameter of lmb_alloc_base() is the maximum physical address of the to be reserved LMB area. Currently this is the start of DRAM bank that is considered for LMB area reservation + min(DRAM bank size, bootm_size). In case bootm_low is set to non-zero, this maximum physical address has to be shifted upward, to min(DRAM bank start + size, bootm_low + bootm_size), otherwise the reserved memory may be below bootm_low address. In case of multiple DRAM banks, the current change reserves top part of the first bank, and reserves the rest of memory in the follow up banks. Signed-off-by: Marek Vasut <marek.vasut+rene...@mailbox.org> --- Cc: Geert Uytterhoeven <ge...@linux-m68k.org> Cc: Hans Verkuil <hverkuil-ci...@xs4all.nl> Cc: Heinrich Schuchardt <xypron.g...@gmx.de> Cc: Kuninori Morimoto <kuninori.morimoto...@renesas.com> Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com> Cc: Niklas Söderlund <niklas.soderl...@ragnatech.se> Cc: Simon Glass <s...@chromium.org> Cc: Tom Rini <tr...@konsulko.com> Cc: Wolfram Sang <w...@kernel.org> --- boot/image-fdt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/boot/image-fdt.c b/boot/image-fdt.c index 75bdd55f326..5e4aa9de0d2 100644 --- a/boot/image-fdt.c +++ b/boot/image-fdt.c @@ -217,14 +217,14 @@ int boot_relocate_fdt(struct lmb *lmb, char **of_flat_tree, ulong *of_size) if (start + size < low) continue; - usable = min(size, (u64)mapsize); + usable = min(start + size, (u64)(low + mapsize)); /* * At least part of this DRAM bank is usable, try * using it for LMB allocation. */ of_start = map_sysmem((ulong)lmb_alloc_base(lmb, - of_len, 0x1000, start + usable), of_len); + of_len, 0x1000, usable), of_len); /* Allocation succeeded, use this block. */ if (of_start != NULL) break; -- 2.43.0