fdt: Fix bootm_low handling
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+renesas@mailbox.org>
diff --git a/boot/image-fdt.c b/boot/image-fdt.c
index 75bdd55..5e4aa9d 100644
--- a/boot/image-fdt.c
+++ b/boot/image-fdt.c
@@ -217,14 +217,14 @@
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;