Hi Magnus, On Mon, Mar 22, 2021 at 3:22 AM Magnus Damm <magnus.damm@xxxxxxxxx> wrote: > On Sun, Mar 21, 2021 at 11:03 PM Geert Uytterhoeven > <geert@xxxxxxxxxxxxxx> wrote: > > On Sun, Mar 21, 2021 at 1:06 PM Magnus Damm <damm@xxxxxxxxxxxxx> wrote: > > > From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx> > > > Include hints in the DTS for KZM9G on how to build a kernel that may be booted > > > using the old on-board boot loader. Special handling includes: > > > - The DTB needs to be appended to the zImage before generating the uImage > > > - LOADADDR needs to be set to 0x48008000 to be able to generate an uImage > > > - CONFIG_ATAGS=n is needed for the board to boot > > > > > > Perhaps there is a better place where this kind of information should be > > > placed? Many years ago the LOADADDR information used to be part of the kernel > > > makefiles (and make uImage just worked out of the box) but when going DTS > > > and zImage this seems to have been dropped. So these days special care is > > > needed to build a uImage file which is required by the boot loader. > > > > > > Not-Yet-Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx> > > > --- 0001/arch/arm/boot/dts/sh73a0-kzm9g.dts > > > +++ work/arch/arm/boot/dts/sh73a0-kzm9g.dts 2021-03-21 18:10:53.515741849 +0900 > > > @@ -2,9 +2,24 @@ > > > /* > > > * Device Tree Source for the KZM-A9-GT board > > > * > > > - * Copyright (C) 2012 Horms Solutions Ltd. > > > + * The KZM9G board comes with on-board out-of-tree U-Boot from 2012 with: > > > + * uImage support but without zImage support > > > > Funny, mine (which I never upgraded) has: > > > > U-Boot 2013.01.-rc1 (Nov 15 2012 - 11:13:00) > > > > and does boot zImage, with appended DTB. > > My board has serial number k0000019 and gives the following printout at boot: > > U-Boot 2012.04.01-00384-g4398d55-dirty (June 05 2012 - 19:45:48) > > This is also the original bootloader, but it might just happen to be > an early development snapshot. Mine was used by Uli before. Perhaps he upgraded the boot loader? > > > + * make ARCH=arm CROSS_COMPILE=_ uImage LOADADDR=0x48008000 > > > + * rm arch/arm/boot/zImage > > > + * make ARCH=arm CROSS_COMPILE=_ dtbs zImage > > > + * cat arch/arm/boot/dts/sh73a0-kzm9g.dtb >> arch/arm/boot/zImage > > > + * $(cut -f 3- -d ' ' < arch/arm/boot/.uImage.cmd) > > > + * > > > + * For a working recent kernel (v5.10+) the following configuration is needed: > > > + * CONFIG_ARM_APPENDED_DTB=y > > > + * CONFIG_ATAGS=n > > > * > > > - * Based on sh73a0-kzm9g.dts > > > + * The shmobile_defconfig works well after setting CONFIG_ATAGS=n > > > > Why CONFIG_ATAGS=n? I have CONFIG_ATAGS=y in my .config. > > I tried various boot-related options to see if it would unbreak the > situation. And deselecting ATAGS happened to fix the issue. > > By the way, on this board it seems the bootloader environment comes > without bootargs set. > > > IIRC, shmobile_defconfig works, if I change CONFIG_CMDLINE to match > > what I need, as U-Boot cannot update chosen/cmdline in an appended DTB. > > So I've locally modified .config from shmobile_defconfig default: > CONFIG_CMDLINE="" > to: > CONFIG_CMDLINE="ignore_loglevel" > CONFIG_CMDLINE_FROM_BOOTLOADER=y > > This also seems to fix the issue - thank you! I just realized that for passing the kernel command line to an appended DTB, you need CONFIG_ARM_ATAG_DTB_COMPAT=y, too. Unfortunately that doesn't seem to help: the kernel doesn't boot (no output, haven't tried DEBUG_LL). However, ever plain shmobile_defconfig seems to be very flaky on kzm9g: the kernel locks up in the middle of the boot. > Related to ATAGS or not, on the console I get the following on v5.10: > [ 0.000000] OF: fdt: Ignoring memory range 0x40000000 - 0x4800000 > > This is similar to the output on from the old v3.18 kernel I happen to > have around: > Ignoring memory range 0x41000000 - 0x48000000 That's normal, you cannot use memory below the kernel load address. > Does the kzm9g boot all the way to user space for you? Perhaps my > board is busted but I seem to get some oopses and freeze. My own kernel works well (I test it after each renesas-drivers release), albeit with an "irq nobody cared" warning (which has been there forever, and might explain the lock-up). I've sent its config by PM. Other known issues on kzm9g are that secondary CPU bringup is a bit unreliable, especially during resume from s2ram, and that switching to DT-based l2c-310 would break secondary CPU bringup completely (still the case last time I tried). > For anyone with an old bootloader, what do you think about documenting > the LOADADDR and how to build an uImage? https://elinux.org/R-Mobile/Boards/KZM-A9-GT Feel free to update! > Is there some way we can make the kernel boot out-of-the-box with > shmobile_defconfig? Upgrade to a modern U-Boot, everywhere? Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
