A38x: Broken Linux kernel booting over UART

[Pali Rohár]

On Monday 11 October 2021 10:32:22 Tom Rini wrote:
> On Mon, Oct 11, 2021 at 04:25:48PM +0200, Pali Rohár wrote:
> > On Monday 11 October 2021 10:03:21 Tom Rini wrote:
> > > On Mon, Oct 11, 2021 at 12:13:29PM +0200, Pali Rohár wrote:
> > > 
> > > > Hello!
> > > > 
> > > > Current U-Boot master has broken booting of Linux kernel over UART on
> > > > A38x.
> > > > 
> > > > After transferring image over UART it just prints:
> > > > 
> > > > CACHE: Misaligned operation at range [01000000, 014e5d96]
> > > > ## Total Size      = 0x004e5d96 = 5135766 Bytes
> > > > ## Start Addr      = 0x01000000
> > > > Kernel image @ 0x1000000 [ 0x000000 - 0x4e0e60 ]
> > > > FDT and ATAGS support not compiled in
> > > > 
> > > > resetting ...
> > > > 
> > > > It resets board and does not boot kernel. Note that I'm trying to boot
> > > > recent 5.15 kernel image, not something old.
> > > > 
> > > > I did git bisect and it found following commit which broke booting:
> > > > 
> > > > 9774462e34faaa64a91eb9c68b438a52d22bba6a is the first bad commit
> > > > commit 9774462e34faaa64a91eb9c68b438a52d22bba6a
> > > > Author: Tom Rini <trini at konsulko.com>
> > > > Date:   Mon Aug 30 09:16:30 2021 -0400
> > > > 
> > > >     arm: Disable ATAGs support
> > > > 
> > > > Prior this commit booting working fine.
> > > > 
> > > > Do you have any idea what is with above commit? Or any hints?
> > > 
> > > Can you provide the full log of what you're doing?  And what's in that
> > > image you're passing, exactly?  Thanks.
> > 
> > Here is full log:
> > 
> > $ make CROSS_COMPILE=arm-linux-gnueabihf- turris_omnia_defconfig
> > ...
> > $ make CROSS_COMPILE=arm-linux-gnueabihf- -j8
> > ...
> > $ ./tools/kwboot -b ./u-boot-spl.kwb -B 5200000 -t /dev/ttyUSB0
> > Patching image boot signature to UART
> > Injecting binary header code for changing baudrate to 5200000 Bd
> > Injecting code for changing baudrate back
> > Aligning image header to Xmodem block size
> > Sending boot message. Please reboot the target...-
> > Waiting 2s and flushing tty
> > Sending boot image header (115072 bytes)...
> >   0 % [......................................................................]
> > ...
> >  93 % [...........................................................           ]
> > Done
> > 
> > U-Boot SPL 2021.10-00600-gf331497d3ad4 (Oct 11 2021 - 16:13:39 +0200)
> > High speed PHY - Version: 2.0
> > MiniPCIe/mSATA card detection... MiniPCIe
> > Detected Device ID 6820
> > board SerDes lanes topology details:
> >  | Lane # | Speed |  Type       |
> >  --------------------------------
> >  |   0    |   5   | PCIe0       |
> >  |   1    |   5   | USB3 HOST0  |
> >  |   2    |   5   | PCIe1       |
> >  |   3    |   5   | USB3 HOST1  |
> >  |   4    |   5   | PCIe2       |
> >  |   5    |   0   | SGMII2      |
> >  --------------------------------
> > High speed PHY - Ended Successfully
> > mv_ddr: 14.0.0 
> > DDR3 Training Sequence - Switching XBAR Window to FastPath Window
> > mv_ddr: completed successfully
> > Disabling MCU watchdog... disabled
> > Trying to boot from BOOTROM
> > Returning to BootROM (return address 0xffff05c4)...
> > 
> > Changing baudrate to 5200000 Bd
> > 
> > Sending boot image data (747780 bytes)...
> >   0 % [......................................................................]
> > ...
> >  99 % [.................................                                     ]
> > Done
> > Finishing transfer
> > 
> > Changing baudrate back to 115200 Bd
> > 
> > [Type Ctrl-\ + c to quit]
> > 
> > 
> > U-Boot 2021.10-00600-gf331497d3ad4 (Oct 11 2021 - 16:13:39 +0200)
> > 
> > SoC:   MV88F6820-A0 at 1600 MHz
> > DRAM:  2 GiB (800 MHz, 32-bit, 2T, ECC not enabled)
> > WDT:   Started watchdog at 20300 with servicing (60s timeout)
> > MMC:   mv_sdh: 0
> > Loading Environment from SPIFlash... SF: Detected s25fl164k with page size 256 Bytes, erase size 4 KiB, total 8 MiB
> > OK
> > Model: Turris Omnia
> > Turris Omnia:
> >   RAM size: 2048 MiB
> >   Serial Number: 0000000B00007B3C
> > Regdomain set to **
> > Net:   eth0: ethernet at 70000, eth1: ethernet at 30000, eth2: ethernet at 34000
> > =>
> > 
> > $ kermit
> > C-Kermit>set line /dev/ttyUSB0
> > C-Kermit>set speed 115200
> > C-Kermit>set carrier-watch off
> > C-Kermit>connect
> > Connecting to /dev/ttyUSB0, speed 115200
> >  Escape character: Ctrl-\ (ASCII 28, FS): enabled
> > Type the escape character followed by C to get back,
> > or followed by ? to see other options.
> > ----------------------------------------------------
> > 
> > => echo $uart_boot
> > loadb $kernel_addr_r 5200000 && part uuid mmc 0:1 partuuid && setenv bootargs earlyprintk rootwait console=ttyS0,115200 rootfstype=btrfs root=PARTUUID=${partuuid} rootflags=commit=5,subvol=@ rw cfg80211.freg=${regdomain} && bootz ${kernel_addr_r}
> > => run uart_boot
> > ## Switch baudrate to 5200000 bps and press ENTER ...
> > C-Kermit>set speed 5200000
> > ?No keywords match - 5200000 (,Transmission rate for /dev/ttyUSB0 (bits per second))
> > 
> > ?SET SPEED fails, speed is 5260273
> > C-Kermit>send /tmp/kernel
> > C-Kermit>set speed 115200
> > /dev/ttyUSB0, 115200 bps
> > C-Kermit>connect
> > CACHE: Misaligned operation at range [01000000, 014e5d96]
> > ## Total Size     = 0x004e5d96 = 5135766 Bytes
> > ## Start Addr      = 0x01000000
> > ## Switch baudrate to 115200 bps and press ESC ...
> > Kernel image @ 0x1000000 [ 0x000000 - 0x4e0e60 ]
> > FDT and ATAGS support not compiled in
> > 
> > resetting ...
> 
> OK, and is /tmp/kernel something with an appended dtb then?

Yes, single image suitable for single kermit UART transfer:
cat arch/arm/boot/zImage arch/arm/boot/dts/armada-385-turris-omnia.dtb > /tmp/kernel