Hi Simon, > -----Original Message----- > From: s...@google.com [mailto:s...@google.com] On Behalf Of Simon Glass > Sent: Saturday, June 09, 2018 3:29 AM > To: Michal Simek <michal.si...@xilinx.com> > Cc: Siva Durga Prasad Paladugu <siva...@xilinx.com>; U-Boot Mailing List > <u-boot@lists.denx.de>; Tom Rini <tr...@konsulko.com> > Subject: Re: [PATCH 1/4] lib: fdtdec: Fill initial ram top with DDR start > value > from dt > > Hi, > > > On 7 June 2018 at 06:18, Michal Simek <michal.si...@xilinx.com> wrote: > > Hi, > > > > On 5.6.2018 09:20, Siva Durga Prasad Paladugu wrote: > >> Fill initial ram top with DDR base addr value from DT as not filling > >> it here always assumes it as zero while calculating relocation offset > >> and hence lead to failures in somecases. This will assumed as zero if > >> CONFIG_SYS_SDRAM_BASE is not defined. > >> > >> Signed-off-by: Siva Durga Prasad Paladugu > >> <siva.durga.palad...@xilinx.com> > >> Signed-off-by: Michal Simek <michal.si...@xilinx.com> > >> --- > >> lib/fdtdec.c | 1 + > >> 1 file changed, 1 insertion(+) > >> > >> diff --git a/lib/fdtdec.c b/lib/fdtdec.c index f4e8dbf..34ef9b8 > >> 100644 > >> --- a/lib/fdtdec.c > >> +++ b/lib/fdtdec.c > >> @@ -1172,6 +1172,7 @@ int fdtdec_setup_memory_size(void) > >> } > >> > >> gd->ram_size = (phys_size_t)(res.end - res.start + 1); > >> + gd->ram_top = (unsigned long)res.start; > >> debug("%s: Initial DRAM size %llx\n", __func__, > >> (unsigned long long)gd->ram_size); > >> > >> > > > > I am curious about ram_top meaning. It is used more as ram_base. > > > > I expect we can workaround it by board_get_usable_ram_top() where we > > decode it exactly the same as patched fdtdec_setup_memory_size() but I > > don't think it is better solution than this one. > > > > Simon/Tom: any comment? > > I wonder why it is not set to res.end in this patch? > > Comments from global_data.h: > > unsigned long ram_top; /* Top address of RAM used by U-Boot */ > phys_size_t ram_size; /* RAM size */
Yes, it holds the ram high address but, initially it should contain start address then in routine setup_dest_addr() (file common_board_f.c), it will be updated by getting the total mem size as below. gd->ram_top += get_effective_memsize(); Lets consider if start address is non zero then it results in wrong ram_top without this patch. So, this patch fixes it by initializing it to ram start address and later in setup_dest_addr(), it will be updated to actual ram high address. Otherway of fixing it is, we should add new variable to gd_t to hold ram_start and then while calculating ram_top in setup_dest_addr(), we should use it as gd->ram_top = gd->ram_start + get_effective_memsize() as gd->bd->bi_dram[0].start didn’t get filled by this time during init. Thanks, Siva > > Regards, > Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
