Hi, On 2/12/21 11:50 PM, Guenter Roeck wrote: > On Fri, Feb 12, 2021 at 04:34:04PM -0600, Rob Herring wrote: >> On Fri, Feb 12, 2021 at 3:01 PM Rob Herring <robh@xxxxxxxxxx> wrote: >>> >>> On Fri, Feb 12, 2021 at 9:17 AM Guenter Roeck <linux@xxxxxxxxxxxx> wrote: >>>> >>>> On Fri, Feb 12, 2021 at 08:16:04AM -0600, Rob Herring wrote: >>>>> On Thu, Feb 11, 2021 at 9:31 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote: >>>>>> >>>>>> Hi Rob, >>>>>> >>>>>> On Wed, Feb 03, 2021 at 03:26:03PM -0600, Rob Herring wrote: >>>>>>> This adds the following commits from upstream: >>>>>>> >>>>>>> 183df9e9c2b9 gitignore: Ignore the swp files >>>>>>> 0db6d09584e1 gitignore: Add cscope files >>>>>>> 307afa1a7be8 Update Jon Loeliger's email >>>>>>> ca16a723fa9d fdtdump: Fix gcc11 warning >>>>>>> 64990a272e8f srcpos: increase MAX_SRCFILE_DEPTH >>>>>>> 163f0469bf2e dtc: Allow overlays to have .dtbo extension >>>>>>> 3b01518e688d Set last_comp_version correctly in new dtb and fix potential version issues in fdt_open_into >>>>>>> f7e5737f26aa tests: Fix overlay_overlay_nosugar test case >>>>>>> 7cd5d5fe43d5 libfdt: Tweak description of assume-aligned load helpers >>>>>>> a7c404099349 libfdt: Internally perform potentially unaligned loads >>>>>>> bab85e48a6f4 meson: increase default timeout for tests >>>>>>> f8b46098824d meson: do not assume python is installed, skip tests >>>>>>> 30a56bce4f0b meson: fix -Wall warning >>>>>>> 5e735860c478 libfdt: Check for 8-byte address alignment in fdt_ro_probe_() >>>>>>> 67849a327927 build-sys: add meson build >>>>>>> 05874d08212d pylibfdt: allow build out of tree >>>>>>> 3bc3a6b9fe0c dtc: Fix signedness comparisons warnings: Wrap (-1) >>>>>>> e1147b159e92 dtc: Fix signedness comparisons warnings: change types >>>>>>> 04cf1fdc0fcf convert-dtsv0: Fix signedness comparisons warning >>>>>>> b30013edb878 libfdt: Fix kernel-doc comments >>>>>>> >>>>>>> Signed-off-by: Rob Herring <robh@xxxxxxxxxx> >>>>>> >>>>>> This patch causes my little-endian microblaze qemu emulations to fail >>>>>> silently (no console output) in next-20210211. Reverting this patch >>>>>> together with "scripts: dtc: Build fdtoverlay tool" fixes the problem. >>>>> >>>>> My guess would be something in libfdt. Maybe 7cd5d5fe43d5 or >>>>> a7c404099349, though that should return to historical behavior. >>>>> >>>>> Can you give me the qemu command line and kernel cfg? >>>>> >>>> I copied everything you should need to build a kernel (including toolchain) >>>> to http://server.roeck-us.net/qemu/microblazeel/ >>>> >>>> [ wow, I really need to update that compiler ] >>> >>> I can't seem to get BE/LE nor reverted or not working. It's always >>> dying in microblaze_cache_init() based on the last print. It's your >>> config, but gcc 10.1.0 off of kernel.org. >> >> It seems gcc 10.1 does not work. Seems to die before here: >> >> pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768 >> >>> There is at least one possible problem here that the FDT may only be 4 >>> byte aligned. The assumption is 8 bytes to not have misaligned >>> accesses (and only for 64-bit accesses if 4 byte aligned). That's an >>> issue with the qemu image loading depending on the sizes and >>> combination of images loaded. That doesn't explain your failure >>> though. As the initrd is a multiple of 8 bytes, you should be fine. >> >> It's the built-in dtb alignment that is the problem. I had noticed >> this earlier, then discovered I had no built-in DTB and QEMU provides >> a default. And changing didn't help because on broken gcc-10 it was 8 >> byte aligned. None of that should matter because we're not using the >> built-in either, right? Wrong! The assembly entry code copies the >> bootloader dtb into the built-in dtb space. I remember this now from >> the last time I cleaned up the early DT code. I suppose the reason is >> the bootloader dtb is not or may not be at an address mapped early. > I have tried 9.3 and 10.0 from https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/ but none of them did boot on real HW. Xilinx stayed on 9.2 and I have asked team to generate gcc 10/10.1 for me to be able to try it myself. > I think the problem is here: > > /* initialize device tree for usage in early_printk */ > early_init_devtree(_fdt_start); > > That probably also explains why enabling earlycon doesn't help. Can you please elaborate more on it? I see earlycon to be enabled quite early. [ 0.000000] Ramdisk addr 0x00000000, [ 0.000000] Compiled-in FDT at (ptrval) [ 0.000000] earlycon: ns16550a0 at MMIO 0x44a01000 (options '115200n8') [ 0.000000] printk: bootconsole [ns16550a0] enabled [ 0.000000] cma: Reserved 16 MiB at 0xaec00000 > >> I'd really like to get rid of that copy. Anyway, the oneliner below >> fixes it. We need it either way, but I'd like some comments on the >> copy. >> > > I can not comment on the copy, but the change below does indeed fix > the problem. Feel free to add > > Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> > > to the patch if you send it out. Please send the patch. Would be the best as early as possible and I will queue it for 5.12. Thanks, Michal
