Thanks for doing this. I often encounter situations where I need to test whether or not a particular application would be benefit from PREEMPT_RT or not, but it's always been somewhat of a hassle to set up an environment where one can easily swap between PREEMPT and PREEMPT_RT for testing. Now, it's just a matter of modifying config.txt. That's great!
I'm excited to test a few things, but unfortunately on my CM4-Lite device, I can't get it to boot. kernel=kernel8.img boots fine. kernel=kernel8_rt.img doesn't seem to get past the bootloader. Everything else is identical.
Here's what I see being emitted on the serial port when booting with kernel=kernel8_rt.img.After that...nothing.
rpi-update succeeded, and I can see kernel8_rt.img in the /boot/firmware folder. It's just not booting for some reason.
I'm excited to test a few things, but unfortunately on my CM4-Lite device, I can't get it to boot. kernel=kernel8.img boots fine. kernel=kernel8_rt.img doesn't seem to get past the bootloader. Everything else is identical.
Here's what I see being emitted on the serial port when booting with kernel=kernel8_rt.img.
Code:
0.10 RPi: BOOTSYS release VERSION:5f18ffb6 DATE: 2024/07/30 TIME: 14:02:35 0.14 BOOTMODE: 0x06 partition 0 build-ts BUILD_TIMESTAMP=1722344555 serial e1dcac7d boardrev a03140 stc 514134 0.31 PM_RSTS: 0x00001020 0.31 part 00000000 reset_info 00000000 0.34 uSD voltage 3.3V 0.60 Initialising SDRAM 'Samsung' 8Gb x1 total-size: 8 Gbit 3200 0.63 DDR 3200 0 0 8 152 1.01 OTP boardrev a03140 bootrom 48b0 48b0 1.03 Customer key hash 0000000000000000000000000000000000000000000000000000000000000000 1.10 VC-JTAG unlocked 1.85 RPi: BOOTLOADER release VERSION:5f18ffb6 DATE: 2024/07/30 TIME: 14:02:35 1.90 BOOTMODE: 0x06 partition 0 build-ts BUILD_TIMESTAMP=1722344555 serial e1dcac7d boardrev a03140 stc 1790120 1.25 Boot mode: SD (01) order f3754 1.39 SD HOST: 200000000 CTL0: 0x00800000 BUS: 400000 Hz actual: 390625 HZ div: 512 (256) status: 0x1fff0000 delay: 276 1.50 SD HOST: 200000000 CTL0: 0x00800f00 BUS: 400000 Hz actual: 390625 HZ div: 512 (256) status: 0x1fff0000 delay: 276 1.61 OCR c0ff8000 [2]CID: 00ad4c535553443030103a050d6e0188CSD: 400e0032db790000ec537f800a400000 1.69 SD: bus-width: 4 spec: 2 SCR: 0x02358487 0x00000000 1.77 SD HOST: 200000000 CTL0: 0x00800f04 BUS: 50000000 Hz actual: 50000000 HZ div: 4 (2) status: 0x1fff0000 delay: 2 1.86 MBR: 0x00002000, 524288 type: 0x0c 1.88 MBR: 0x00082000, 2097152 type: 0x83 1.92 MBR: 0x00282000,59322368 type: 0x83 1.96 MBR: 0x00000000, 0 type: 0x00 1.99 Trying partition: 0 1.02 type: 32 lba: 8192 'mkfs.fat' ' bootfs ' clusters 130554 (4) 1.08 rsc 32 fat-sectors 1020 root dir cluster 2 sectors 0 entries 0 1.14 FAT32 clusters 130554 1.23 [sdcard] autoboot.txt not found 1.23 Select partition rsts 0 C(boot_partition) 0 EEPROM config 0 result 0 1.30 Trying partition: 0 1.33 type: 32 lba: 8192 'mkfs.fat' ' bootfs ' clusters 130553 (4) 1.39 rsc 32 fat-sectors 1020 root dir cluster 2 sectors 0 entries 0 1.45 FAT32 clusters 130553 1.49 Read config.txt bytes 1059 hnd 0xa 1.52 gpio_cmd: '26=op,np,dh' pins: 26-26 drive: 1 fsel: 1 term: 0 1.58 gpio_cmd: '44=op,np,dh' pins: 44-44 drive: 1 fsel: 1 term: 0 1.64 gpio_cmd: '6-7=ip' pins: 6-7 drive: -1 fsel: 0 term: -1 1.69 gpio_cmd: '10-11=ip' pins: 10-11 drive: -1 fsel: 0 term: -1 1.75 gpio_cmd: '16-18=ip' pins: 16-18 drive: -1 fsel: 0 term: -1 1.81 gpio_cmd: '19-24=op,pd,dl' pins: 19-24 drive: 0 fsel: 1 term: 1 1.87 gpio_cmd: '45=op,pd,dl' pins: 45-45 drive: 0 fsel: 1 term: 1 1.95 [sdcard] pieeprom.upd not found 1.98 [sdcard] recover4.elf not found 2.02 [sdcard] recovery.elf not found 2.26 Read start4.elf bytes 2263968 hnd 0x7430 2.29 Read fixup4.dat bytes 5456 hnd 0x26d 2.31 0x00a03140 0x00000000 0x00001fff 2.35 MEM GPU: 76 ARM: 948 TOTAL: 1024 2.04 Firmware: 5560078dcc8591a00f57b9068d13e5544aeef3aa Apr 30 2025 13:33:39 2.36 Starting start4.elf @ 0xfec00200 partition 0 2.38 PCI0 reset 2.49 +rpi-update succeeded, and I can see kernel8_rt.img in the /boot/firmware folder. It's just not booting for some reason.
Statistics: Posted by JinShil — Wed May 28, 2025 4:55 am