Hi Uwe, On Fri, 2025-11-21 at 09:52 +0100, Uwe Kleine-König wrote: > Hello Benjamin, > > On Thu, Nov 20, 2025 at 11:11:07AM +0100, Benjamin Drung wrote: > > On Thu, 2025-11-20 at 08:58 +0100, Uwe Kleine-König wrote: > > > On Mon, Nov 17, 2025 at 02:05:41AM +0100, Benjamin Drung wrote: > > > > On Wed, 2025-11-05 at 20:14 +0100, Uwe Kleine-König wrote: > > > > > Can you try adding > > > > > > > > > > earlyprintk=serial,0x7e215040 > > > > > > > > > > to the kernel commandline. Not sure this activates the right > > > > > procedures, > > > > > maybe try it with the working kernel first. > > > > > > > > I tried with the working kernel 6.12.43+deb13-rpi but these were the > > > > earliest lines: > > > > > > > > [ 4.116565] printk: legacy console [ttyS1] enabled > > > > [ 4.129635] printk: legacy bootconsole [earlycon0] disabled > > > > [ 4.147050] bcm2835-power bcm2835-power: Broadcom BCM2835 power > > > > domains driver > > > > [ 4.160972] mousedev: PS/2 mouse device common for all mice > > > > [ 4.172622] i2c-bcm2835 20805000.i2c: Could not read clock-frequency > > > > property > > > > [ 4.186585] bcm2835-wdt bcm2835-wdt: Broadcom BCM2835 watchdog timer > > > > > > > > I tried with 6.12.57+deb13-rpi but that failed to boot and the > > > > earlyprintk line did not give any additional logs. > > > > > > Can you please provide a full kernel log of the working kernel? > > > > dmesg log is attached. > > > > > Also please provide the output of: > > > > > > for f in /proc/tty/driver/*; do echo $f; sed 's/^/ /' < $f; done > > > > /proc/tty/driver/serial > > serinfo:1.0 driver revision: > > 0: uart:unknown port:00000000 irq:0 > > 1: uart:16550 mmio:0x20215040 irq:53 tx:15629 rx:0 RTS|CTS|DTR > > 2: uart:unknown port:00000000 irq:0 > > 3: uart:unknown port:00000000 irq:0 > > /proc/tty/driver/ttyAMA > > serinfo:1.0 driver revision: > > 0: uart:PL011 rev2 mmio:0x20201000 irq:81 tx:452 rx:980 RTS|CTS|DTR > > OK, is > > earlyprintk=serial,0x20215040 > > more communicative then?
Nope, but I found https://www.raspberrypi.com/documentation/computers/configuration.html#enabling-early-console-for-linux and setting earlycon=uart8250,mmio32,0x20215040 worked. The kernel 6.12.43+deb13-rpi booted with printing the early lines as well (see dmesg of previous mail). With all other experiments cleaned, I tried the latest kernel: ``` $ cat /etc/default/raspi-extra-cmdline earlycon=uart8250,mmio32,0x20215040 $ update-initramfs -u ``` I got following logs before it got stuck: ``` [ 0.000000] Booting Linux on physical CPU 0x0 [ 0.000000] Linux version 6.12.57+deb13-rpi ([email protected]) (arm-linux-gnueabi-gcc-14 (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44) #1 Debian 6.12.57-1 (2025-11-05) [ 0.000000] CPU: ARMv6-compatible processor [410fb767] revision 7 (ARMv7), cr=00c5387d [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT nonaliasing instruction cache [ 0.000000] OF: fdt: Machine model: Raspberry Pi Zero W Rev 1.1 [ 0.000000] random: crng init done [ 0.000000] earlycon: uart8250 at MMIO32 0x20215040 (options '') [ 0.000000] printk: legacy bootconsole [uart8250] enabled [ 0.000000] Memory policy: Data cache writeback [ 0.000000] Reserved memory: bypass linux,cma node, using cmdline CMA params instead [ 0.000000] OF: reserved mem: node linux,cma compatible matching fail [ 0.000000] cma: Reserved 64 MiB at 0x17000000 on node -1 ``` It looks like being cma related and I found a cma boot option in /etc/default/raspi-firmware. So I modified /boot/firmware/cmdline.txt and changed cma=64M to cma=0. Then the system booted without problems: ``` [...] [ 0.000000] Reserved memory: bypass linux,cma node, using cmdline CMA params instead [ 0.000000] OF: reserved mem: node linux,cma compatible matching fail [ 0.000000] Zone ranges: [ 0.000000] Normal [mem 0x0000000000000000-0x000000001bffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000000000000-0x000000001bffffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x000000001bffffff] [ 0.000000] Kernel command line: dma.dmachans=0x7ff5 bcm2708.boardrev=0x9000c1 bcm2708.serial=0x8bb1238 bcm2708.uart_clock=48000000 bcm2708.disk_led_gpio=47 smsc95xx.macaddr=B8:27:EB:BB:12:38 vc_mem.mem_base=0x1ec00000 vc_mem.mem_size=0x20000000 console=tty0 console=ttyS1,115200 root=/dev/mmcblk0p2 rw fsck.repair=yes net.ifnames=0 cma=0 rootwait earlycon=uart8250,mmio32,0x20215040 [...] ``` Then I persisted this change by setting CMA=0 in /etc/default/raspi-firmware: ``` $ grep -Ev '^(#|$)' /etc/default/raspi-firmware CMA=0 $ update-initramfs -u ``` This config removes the cma cmdline option completely. The system still boots: ``` [...] [ 0.000000] Memory policy: Data cache writeback [ 0.000000] Reserved memory: created CMA memory pool at 0x17000000, size 64 MiB [ 0.000000] OF: reserved mem: initialized node linux,cma, compatible id shared-dma-pool [ 0.000000] OF: reserved mem: 0x17000000..0x1affffff (65536 KiB) map reusable linux,cma [ 0.000000] Zone ranges: [ 0.000000] Normal [mem 0x0000000000000000-0x000000001bffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000000000000-0x000000001bffffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x000000001bffffff] [ 0.000000] Kernel command line: dma.dmachans=0x7ff5 bcm2708.boardrev=0x9000c1 bcm2708.serial=0x8bb1238 bcm2708.uart_clock=48000000 bcm2708.disk_led_gpio=47 smsc95xx.macaddr=B8:27:EB:BB:12:38 vc_mem.mem_base=0x1ec00000 vc_mem.mem_size=0x20000000 console=tty0 console=ttyS1,115200 root=/dev/mmcblk0p2 rw fsck.repair=yes net.ifnames=0 rootwait earlycon=uart8250,mmio32,0x20215040 [...] ``` That should hopefully narrow down the issue space. -- Benjamin Drung Debian & Ubuntu Developer
