Hi Stefan, Hi Pali, On Fri, Feb 10, 2023 at 9:29 AM Pali Rohár <[email protected]> wrote: > > On Thursday 09 February 2023 17:37:54 Tony Dinh wrote: > > Hi Pali, > > > > On Thu, Feb 9, 2023 at 1:45 PM Pali Rohár <[email protected]> wrote: > > > > > > On Thursday 09 February 2023 13:33:23 Tony Dinh wrote: > > > > Hi Stefan, > > > > > > > > On Wed, Feb 8, 2023 at 11:15 PM Stefan Roese <[email protected]> wrote: > > > > > > > > > > Hi Tony, > > > > > > > > > > On 2/9/23 04:17, Tony Dinh wrote: > > > > > > Hi Stefan, > > > > > > > > > > > > On Fri, Feb 3, 2023 at 4:11 PM Tony Dinh <[email protected]> wrote: > > > > > >> > > > > > >> Hi Pali, > > > > > >> > > > > > >> On Fri, Feb 3, 2023 at 2:05 PM Pali Rohár <[email protected]> wrote: > > > > > >>> > > > > > >>> On Thursday 02 February 2023 19:04:45 Pali Rohár wrote: > > > > > >>>> On Wednesday 01 February 2023 13:13:16 Tony Dinh wrote: > > > > > >>>>> Hi all, > > > > > >>>>> > > > > > >>>>> On Wed, Feb 1, 2023 at 11:05 AM Pali Rohár <[email protected]> > > > > > >>>>> wrote: > > > > > >>>>>> > > > > > >>>>>> On Wednesday 01 February 2023 09:17:15 Michael Walle wrote: > > > > > >>>>>>>>>> When DM_SERIAL is enabled, the device-tree property > > > > > >>>>>>>>>> dm-pre-reloc is > > > > > >>>>>>>>>> required to boot over UART with kwboot. Enable this in a > > > > > >>>>>>>>>> Kirkwood > > > > > >>>>>>>>>> common u-boot dtsi. > > > > > >>>>>>>>> > > > > > >>>>>>>>> My (dev) board unfortunately, have a bootloader which can't > > > > > >>>>>>>>> boot over > > > > > >>>>>>>>> serial. > > > > > >>>>>>>> > > > > > >>>>>>>> This is feature of Marvell BootROM and does not require any > > > > > >>>>>>>> special from > > > > > >>>>>>>> Bootloader. So you should be able to boot over UART (if you > > > > > >>>>>>>> have > > > > > >>>>>>>> accessible pins). > > > > > >>>>>>> > > > > > >>>>>>> I know, but there are known versions ob the bootrom where > > > > > >>>>>>> uart boot > > > > > >>>>>>> isn't supported (correctly). > > > > > >>>>>> > > > > > >>>>>> I heard about it... maybe it is a bug in client software > > > > > >>>>>> (kwboot)? I do > > > > > >>>>>> not have such board if you are interested in it I could try to > > > > > >>>>>> send some > > > > > >>>>>> details how to debug it. > > > > > >>>>> > > > > > >>>>> The Kirkwood SoCs came with different BootROM versions. Version > > > > > >>>>> 1.1 > > > > > >>>>> cannot be booted over UART, but version 1.2 can. I think there > > > > > >>>>> must > > > > > >>>>> be a bug in the BootROM 1.1. The older Kirkwood such as > > > > > >>>>> Sheevaplug, > > > > > >>>>> Dockstar, iConnect boards come with BootROM 1.1. Later version > > > > > >>>>> of > > > > > >>>>> Sheevaplug, GoFlex Home, GoFlex Net, Dreamplug, Pogoplug V4, > > > > > >>>>> Zyxel > > > > > >>>>> NSA310S, NSA320, NSA325 come with BootROM 1.2. So even though > > > > > >>>>> it is > > > > > >>>>> the same SoC, eg. 6281, they are actually produced at a > > > > > >>>>> different time > > > > > >>>>> and have different BootROM versions. > > > > > >>>> > > > > > >>>> There are always multiple revisions of the same SoC. So it is > > > > > >>>> possible > > > > > >>>> that something was broken on first revision of 88F6281 and in > > > > > >>>> next > > > > > >>>> revision was updated BootROM with some fixes. Revision is > > > > > >>>> written on > > > > > >>>> package label and for Armada SoCs it is available also in some > > > > > >>>> register > > > > > >>>> (not sure about Kirkwood). It looks like that there is at least > > > > > >>>> revision > > > > > >>>> Z0 and revision A0 of some Kirkwood SoC. > > > > > >>>> > > > > > >>>> If there is a bug in first revisions then it should be > > > > > >>>> documented in > > > > > >>>> some Kirkwood Errata document. Unfortunately I have never seen > > > > > >>>> it, it is > > > > > >>>> not public, so I have no idea. In any case, if somebody has > > > > > >>>> access to > > > > > >>>> Marvell documents, interesting are these document numbers: > > > > > >>>> > > > > > >>>> * MV-S105223-001 - Differences Between the 88F6192, and 88F6281 > > > > > >>>> Stepping Z0 and A0 > > > > > >>>> * MV-S501081-00 - 88F6180, 88F6192, and 88F6281 Functional > > > > > >>>> Errata, Interface Guidelines, and Restrictions > > > > > >>>> * MV-S501157-U0 - 88F6180, 88F6190, 88F6192, and 88F6281 > > > > > >>>> Functional Errata, Interface Guidelines, and Restrictions > > > > > >>>> > > > > > >>>> One of the option how to investigate or debug this issue without > > > > > >>>> documentation is to dump both BootROM versions (1.1, 1.2) and > > > > > >>>> compare > > > > > >>>> them. Either there is different UART protocol for booting (which > > > > > >>>> needs > > > > > >>>> to be implemented) or UART protocol is buggy and needs some > > > > > >>>> workaround > > > > > >>>> or it is completely broken and does not work. > > > > > >>> > > > > > >>> BootROM is mapped to 0xF8000000 address and is 64 kB long. So via > > > > > >>> U-Boot > > > > > >>> md command it is possible to dump it over console. Or via > > > > > >>> ext4write > > > > > >>> command store it so ext4 fs on sd card / sata disk. > > > > > >> > > > > > >> Thanks for the info. It will be a while before I can get back to > > > > > >> this > > > > > >> BootROM 1.1 vs 1.2 topic. > > > > > >> > > > > > > > > > > > > I have run some more tests, and am quite positive that if the uart0 > > > > > > node exists in the DTS, it must be tagged with dm,pre-reloc. That is > > > > > > consistent with the serial documentation in > > > > > > doc/develop/driver-model/serial-howto.rst. The issue is whether the > > > > > > uart0 node is specified in the DTS. If it is, the dm-pre-reloc tag > > > > > > must also be used. > > > > > > > > > > > > To prove my theory, I've modified the Pogo V4 DTS to look exactly > > > > > > like > > > > > > the NSA310S, as far as uart0 is concerned. The NSA310S does not even > > > > > > have a uart0 node! and DM_SERIAL boots fine with this box. With the > > > > > > patch below, the Pogo V4 can be kwboot and run normally. No > > > > > > dm-pre-reloc tag is needed. > > > > > > > > > > > > diff --git a/arch/arm/dts/kirkwood-pogoplug-series-4.dts > > > > > > b/arch/arm/dts/kirkwood-pogoplug-series-4.dts > > > > > > index 5aa4669ae2..227d5ff802 100644 > > > > > > --- a/arch/arm/dts/kirkwood-pogoplug-series-4.dts > > > > > > +++ b/arch/arm/dts/kirkwood-pogoplug-series-4.dts > > > > > > @@ -24,7 +24,8 @@ > > > > > > }; > > > > > > > > > > > > chosen { > > > > > > - stdout-path = "uart0:115200n8"; > > > > > > + bootargs = "console=ttyS0,115200"; > > > > > > + stdout-path = &uart0; > > > > > > }; > > > > > > > > > > > > gpio_keys { > > > > > > @@ -97,10 +98,6 @@ > > > > > > }; > > > > > > }; > > > > > > > > > > > > -&uart0 { > > > > > > - status = "okay"; > > > > > > -}; > > > > > > - > > > > > > /* > > > > > > * This PCIE controller has a USB 3.0 XHCI controller at 1,0 > > > > > > */ > > > > > > > > > > FWIU, you are hitting a bug in the early serial console code, perhaps > > > > > in serial_check_stdout()? > > > > > > > > Quite possible. But I recall trying the same stdout path as the > > > > NSA310S, i.e. stdout-path = &uart0. So the stdout-path itself is not > > > > the reason. Perhaps the bug is in another part of the function. > > > > > > > > > > > > > > Could you please check if Pogo V4 boots with > > > > > CONFIG_REQUIRE_SERIAL_CONSOLE unset? > > > > > > > > > Indeed, you're right! unset CONFIG_REQUIRE_SERIAL_CONSOLE allows the > > > > Pogo V4 to boot OK, without dm-pre-reloc needed. And it booted > > > > normally with kwboot, all serial input/outputs are OK. > > > > > > > > > > Also, note that just enabling DEBUG_UART would always make the board > > > > > > frozen when u-boot starts. > > > > > > > > > > This should not be the case of course. Are you sure you've correctly > > > > > configured the DEBUG UART? > > > > > > > > I think I did that correctly (we've used that to debug the orion_timer > > > > issue previously). Here is how I've configured it: > > > > > > > > +CONFIG_DEBUG_UART_BASE=0xf1012000 > > > > +CONFIG_DEBUG_UART_CLOCK=250000000 > > > > +CONFIG_DEBUG_UART=y > > > > > > Maybe you hit same issue in mach-kirkwood as me in the past for > > > mach-mvebu? U-Boot code was trying to initialize UART at the _new_ base > > > register address (0xf1012000) when U-Boot was still using the _old_ base > > > register address (0xd0012000). > > > > > > I fixed it by moving code which changes base register address from > > > arch_cpu_init() function to arch_very_early_init() function in commit: > > > https://source.denx.de/u-boot/u-boot/-/commit/5bb2c550b11eb087437740b2a0d1fe780be5aec3 > > > > Thanks for the info! Looking at that patch, I think I'm out of my > > depth :) > > That is pretty simple. It is something like this: > > diff --git a/arch/arm/mach-kirkwood/Kconfig b/arch/arm/mach-kirkwood/Kconfig > index c8a193dd4cdf..ba39e9ae416e 100644 > --- a/arch/arm/mach-kirkwood/Kconfig > +++ b/arch/arm/mach-kirkwood/Kconfig > @@ -5,9 +5,11 @@ config FEROCEON_88FR131 > > config KW88F6192 > bool > + select ARCH_VERY_EARLY_INIT > > config KW88F6281 > bool > + select ARCH_VERY_EARLY_INIT > > config SHEEVA_88SV131 > bool > diff --git a/arch/arm/mach-kirkwood/Makefile b/arch/arm/mach-kirkwood/Makefile > index 3b2eef8d5419..0fb5a2326f5f 100644 > --- a/arch/arm/mach-kirkwood/Makefile > +++ b/arch/arm/mach-kirkwood/Makefile > @@ -6,6 +6,7 @@ > > obj-y = cpu.o > obj-y += cache.o > +obj-y += lowlevel.o > obj-y += mpp.o > > # cpu.o and cache.o contain CP15 instructions which cannot be run in > diff --git a/arch/arm/mach-kirkwood/cpu.c b/arch/arm/mach-kirkwood/cpu.c > index df3e8f11782a..2b493b36c20d 100644 > --- a/arch/arm/mach-kirkwood/cpu.c > +++ b/arch/arm/mach-kirkwood/cpu.c > @@ -189,9 +189,6 @@ int arch_cpu_init(void) > struct kwcpu_registers *cpureg = > (struct kwcpu_registers *)KW_CPU_REG_BASE; > > - /* Linux expects the internal registers to be at 0xf1000000 */ > - writel(KW_REGS_PHY_BASE, KW_OFFSET_REG); > - > /* Enable and invalidate L2 cache in write through mode */ > writel(readl(&cpureg->l2_cfg) | 0x18, &cpureg->l2_cfg); > invalidate_l2_cache(); > diff --git a/arch/arm/mach-kirkwood/lowlevel.S > b/arch/arm/mach-kirkwood/lowlevel.S > index e69de29bb2d1..3b339f97f056 100644 > --- a/arch/arm/mach-kirkwood/lowlevel.S > +++ b/arch/arm/mach-kirkwood/lowlevel.S > @@ -0,0 +1,12 @@ > +/* SPDX-License-Identifier: GPL-2.0+ */ > + > +#include <config.h> > +#include <linux/linkage.h> > + > +ENTRY(arch_very_early_init) > + /* Move internal registers from KW_OFFSET_REG to KW_REGS_PHY_BASE */ > + ldr r0, =KW_REGS_PHY_BASE > + ldr r1, =KW_OFFSET_REG > + str r0, [r1] > + bx lr > +ENDPROC(arch_very_early_init)
Thanks! I'll try this eventually. But please see my response to Stefan below. Would the forced setting CONFIG_DEBUG_UART_BASE=0xd0012000 give us some output from uart0 before arch_early_init ? > > For now I will fix this Pogo V4 with the -u-boot.dtsi, so as > > not to mess up anybody who might try UART booting with kwboot. > > > > Thanks, > > Tony > > > > > > > > So this was another factor why it took me > > > > > > so long to figure this out :) I've just restored everything and > > > > > > removed the uart0 node from the Pogo V4 DTS like above and it is > > > > > > working. > > > > > > > > > > > > But of course, we don't want to change the Pogo V4 DTS, so I will > > > > > > submit another patch just for the Pogo V4 to add -u-boot.dtsi for > > > > > > this > > > > > > box to enable the dm-pre-reloc tag for uart0. > > > > > > > > > > Understood. Regarding Stefan's suggestion about trying using CONFIG_DEBUG_UART_BASE=0xd0012000. Yes, I also tried that address (I'm aware of this address while building kernels for some old Armada 370 boards such as the Mirabox and Netgear RN102). I suspect for some reason, i.e. bug, at the pre-relocation phase we don't even have the uart0 device so DEBUG UART printch() just hangs. Thanks, Tony
