Stefan Seyfried wrote:
Hi Per,
On 04.01.21 14:13, Per Jessen wrote:
In grub, edit the command line, put "console=ttyS0..." last (after "console=tty") and maybe add "earlyprintk=serial,ttyS0,115200", then remove the "loglevel=...", "splash=..." and instead add "debug" to get as much output from the kernel as early as possible.
I tried that, still no more output after this line:
OK, then it is of course possible that the kernel just does not start at all.
If you'd want to give it another try, one method to verify that your command line is actually working for early kernel debugging
I tried the same options with the TW jeOS image, works fine: Loading Linux 5.8.15-1-lpae ... mods Loading initial ramdisk ... EFI stub: Entering in HYP mode with MMU enabled EFI stub: Booting Linux Kernel... EFI stub: Using DTB from configuration table EFI stub: Exiting boot services and installing virtual address map... EHCI failed to shut down host controller. [ 0.000000] Booting Linux on physical CPU 0x0 [ 0.000000] Linux version 5.8.15-1-lpae (geeko@buildhost) (gcc (SUSE Linux) 10.2.1 20200825 [revision c0746a1beb1ba073c7981eb09f55b3d993b32e5c], GNU ld (GNU Binutils; openSUSE Tumbleweed) 2.34.0.20200325-1) #1 SMP Thu Oct 15 08:10:08 UTC 2020 (c680e93) [ 0.000000] CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=30c5387d [ 0.000000] CPU: div instructions available: patching division code [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache [ 0.000000] OF: fdt: Machine model: FriendlyARM NanoPi NEO [ 0.000000] Memory policy: Data cache writealloc [ 0.000000] efi: EFI v2.80 by Das U-Boot [ 0.000000] efi: RTPROP=0x5af49040 SMBIOS=0x5af48000 MEMRESERVE=0x512a7040 [ 0.000000] efi: [Firmware Bug]: ExitBootServices() returned with MMU and Dcache disabled, please fix your firmware! [ 0.000000] efi: CPSR at EFI stub entry : 0x600001da [ 0.000000] efi: SCTLR at EFI stub entry : 0x30c5087d [ 0.000000] efi: CPSR after ExitBootServices() : 0x600001da [ 0.000000] efi: SCTLR after ExitBootServices(): 0x30c50878 [ 0.000000] cma: Reserved 64 MiB at 0x000000005bc00000 Kernel command line: BOOT_IMAGE=/boot/zImage-5.8.15-1-lpae root=UUID=32ca1b87-ae87-4304-8a89-754e69244b54 rw debug earlyprintk=serial,ttyS0,115200 console=ttyS0,115200,8n1 plymouth.enable=0 -- Per Jessen, Zürich (-0.6°C)