On Fri, 6 Dec 2024 at 09:55, Sam Protsenko <[email protected]> wrote: > > Hi Sughosh, > > Commit eb052cbb896f ("lmb: add and reserve memory above ram_top") > causes a regression on the E850-96 board. It looks like it could be > not E850-96 specific though. During U-Boot boot (the most recent > master branch, with this commit present), before U-Boot shell appears, > I observe the next error message, which doesn't happen before this > patch: > > ERROR: reserving fdt memory region failed (addr=f0000000 > size=200000 flags=4) > > The memory node [1] is defined like this in the E850-96 dts: > > memory@80000000 { > device_type = "memory"; > reg = <0x0 0x80000000 0x3ab00000>, > <0x0 0xc0000000 0x40000000>, > <0x8 0x80000000 0x80000000>; > }; > > And the reserved-memory node [2] has only one entry: > > ramoops@f0000000 { > reg = <0x0 0xf0000000 0x200000>; > ... > }; > > Here is the relevant part of 'bdinfo' output: > > lmb_dump_all: > memory.count = 0x3 > memory[0] [0x80000000-0xbaafffff], 0x3ab00000 bytes, flags: none > memory[1] [0xc0000000-0xffffffff], 0x40000000 bytes, flags: none > memory[2] [0x880000000-0x8ffffffff], 0x80000000 bytes, flags: none > reserved.count = 0x4 > reserved[0] [0xb922d000-0xb922ffff], 0x3000 bytes, flags: > no-notify, no-overwrite > reserved[1] [0xb9230e10-0xbaafffff], 0x18cf1f0 bytes, flags: > no-overwrite > reserved[2] [0xc0000000-0xffffffff], 0x40000000 bytes, flags: > no-overwrite > reserved[3] [0x880000000-0x8ffffffff], 0x80000000 bytes, > flags: no-overwrite > > The same error also occurs when I'm trying to boot Linux with 'booti' command: > > Working FDT set to 8a000000 > ERROR: reserving fdt memory region failed (addr=f0000000 > size=200000 flags=4) > Loading Device Tree to 00000000b912a000, end 00000000b922cfff ... OK > > Although I think the device tree portion above is valid, I also tried > to cleanup the 'memory' and 'reserved-memory' nodes like this, to see > if that was going to help working around the issue: > > memory@80000000 { > device_type = "memory"; > reg = <0x0 0x80000000 0x80000000>, > <0x8 0x80000000 0x80000000>; > }; > > reserved-memory { > ... > secure_reserved: secure-os@bab00000 { > reg = <0x0 0xbab00000 0x5500000>; > no-map; > }; > > ramoops@f0000000 { > reg = <0x0 0xf0000000 0x200000>; > ... > }; > }; > > It made the first error message (during the U-Boot boot) go away, but > the later errors (when trying to boot the kernel) still persist. Here > is the relevant 'bdinfo' output with my dts change above applied: > > lmb_dump_all: > memory.count = 0x2 > memory[0] [0x80000000-0xffffffff], 0x80000000 bytes, flags: none > memory[1] [0x880000000-0x8ffffffff], 0x80000000 bytes, flags: none > reserved.count = 0x5 > reserved[0] [0xbab00000-0xbfffffff], 0x5500000 bytes, flags: no-map > reserved[1] [0xf0000000-0xf01fffff], 0x200000 bytes, flags: > no-overwrite > reserved[2] [0xfe72d000-0xfe72ffff], 0x3000 bytes, flags: > no-notify, no-overwrite > reserved[3] [0xfe730dd0-0xffffffff], 0x18cf230 bytes, flags: > no-overwrite > reserved[4] [0x880000000-0x8ffffffff], 0x80000000 bytes, > flags: no-overwrite > > The error messages I'm observing after issuing the 'booti' command are > as follows: > > ERROR: reserving fdt memory region failed (addr=bab00000 > size=5500000 flags=2) > ERROR: reserving fdt memory region failed (addr=f0000000 > size=200000 flags=4) > > It looks like all mentioned error messages are harmless, in a way that > I'm still able to boot Linux, and U-Boot reserved areas still seem to > exist in 'bdinfo'. But seeing error messages like that is definitely a > nuisance by itself, and might be an indicator of some actual issues. > Do you have any remedy for that by chance? Please let me know if you > need more debug input from my side.
This seems to be happening because the board is trying to reserve memory above ram_top with no-map or no-overwrite attributes. To confirm, you can print the value of ram_top in setup_dest_addr(). -sughosh > > Thanks! > > [1] > https://source.denx.de/u-boot/u-boot/-/blob/master/dts/upstream/src/arm64/exynos/exynos850-e850-96.dts#L55 > [2] > https://source.denx.de/u-boot/u-boot/-/blob/master/dts/upstream/src/arm64/exynos/exynos850-e850-96.dts#L144
