- (recommended) Docker buildroot
- Docker buildroot-cheat
- Buildroot
- Code comprehension
- Old (not working)
- DEPRECATED. Use buildroot. I never got this fully working but
flowchart TB
EFI --> busybox --> grub.cfg --> vmlinuz --> init --> main.c --> setup.c
qemu --> bzimage --> vmlinuz --> head.S
+- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +
' bootloader ' ' kernel '
' ' ' '
+------+ ' +-----------------------------------+ +------------------------------+ ' ' +-----------------------------+ +---------------------------------------+ '
| BIOS | --> ' | arch/x86/boot/header.S::call main | --> | arch/x86/boot/main.c::main() | ' --> ' | init/main.c::start_kernel() | --> | arch/x86/kernel/setup.c::setup_arch() | '
+------+ ' +-----------------------------------+ +------------------------------+ ' ' +-----------------------------+ +---------------------------------------+ '
' ' ' '
+- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +
CC arch/x86/kernel/head64.o
CC init/version.o
CC arch/x86/boot/version.o
OBJCOPY arch/x86/boot/compressed/vmlinux.bin
CC arch/x86/boot/compressed/kaslr.o
CC arch/x86/boot/compressed/misc.o
MKPIGGY arch/x86/boot/compressed/piggy.S
AS arch/x86/boot/compressed/piggy.o
OBJCOPY arch/x86/boot/vmlinux.bin
AS arch/x86/boot/header.o
OBJCOPY arch/x86/boot/setup.bin
BUILD arch/x86/boot/bzImage
(recommended) From outside the container:
### minimal
cd /media/sarnobat/unmirrored/trash/buildroot-2021.12/docker-buildroot
docker build -t "advancedclimatesystems/buildroot" .
docker run -i --name buildroot_output advancedclimatesystems/buildroot /bin/echo "Data only."
./scripts/run.sh make qemu_x86_64_defconfig menuconfig
scripts/run.sh make
scripts/run.sh /buildroot_output/images/start-qemu.sh
### change some source code (kernel)
(optional) scripts/run.sh vi /buildroot_output/build/linux-5.4.58//init/main.c +/Run
(optional) scripts/run.sh make linux-rebuild
### change some source code (userland)
(optional) scripts/run.sh vi /buildroot_output/build/busybox-1.31.1/networking/wget.c +/download_one_url(const
(optional) scripts/run.sh make busybox-rebuild # if you change wget.c
Troubleshooting
It's fiddly trying to get userland changes to be copied into the new installation. Here are some suggestions:
1) Make sure you are running the right container (it is easier to not use `scripts/run.sh` to make sure multiple docker images aren't created)
2)
cd /buildroot_output make busybox-rebuild all
(instead of just make busybox-rebuild)
(credits: http://underpop.online.fr/b/buildroot/en/_using_buildroot_during_development.htm.gz)
# looks like you don't need to destroy and rebuild the container for busybox. -For init/main.c, I'm yet to determine how to deploy the changes.-
sudo service docker stop
sudo vi /etc/docker/daemon.json
{
"data-root": "/media/sarnobat/ebay/trash/"
}
sudo chmod 777 /var/run/docker.sock
sudo service docker start
- The Docker container doesn't run the build on startup, it just installs the build tools. You have to kick off the build by running the Makefile
2022: I'm having better luck with this https://github.com/AdvancedClimateSystems/docker-buildroot/blob/master/scripts/run.sh
From inside container: root@b218928410d1: cd ~/buildroot/ && make
After editing source code, you need to stop the container and create a new one. It will preserve your code changes to wget.c (how?) and After building from the original commands (takes just a few mins) - you will see your new print statements. I don't understand exactly why it works but at least it does. I think it worked better when I used scripts/run.sh rather than interactively running the make file from inside the interactive container.
50930 docker ps
50931 ./scripts/run.sh make qemu_x86_64_defconfig menuconfig
50932 ./scripts/run.sh bash
50933 docker build -t .
50934 docker run -i advancedclimatesystems/buildroot /bin/bash
50935 disown %1
50936 cd /media/sarnobat/unmirrored/trash/buildroot-2021.12/docker-buildroot
50937 docker run -i advancedclimatesystems/buildroot /usr/bin/find
50938 docker run -i advancedclimatesystems/buildroot /scripts/run.sh make qemu_x86_64_defconfig menuconfig
50939 docker run -i advancedclimatesystems/buildroot make
50940 ./scripts/run.sh make raspberrypi2_defconfig menuconfig
50941 ./scripts/run.sh make menuconfig
50942 docker run -i --name buildroot_output advancedclimatesystems/buildroot /bin/echo "Data only."
50943 ./scripts/run.sh make menuconfig
50944 ./scripts/run.sh make qemu_x86_64_defconfig menuconfig
50945 ./scripts/run.sh make
50946 ./scripts/run.sh make | tee /tmp/docker.log &!
Creating regular file /root/buildroot/output/images/rootfs.ext2
Creating filesystem with 61440 1k blocks and 15360 inodes
Filesystem UUID: 9fd1248a-5cbc-4177-acc2-f1506ec9389b
Superblock backups stored on blocks:
8193, 24577, 40961, 57345
Allocating group tables: done
Writing inode tables: done
Copying files into the device: done
Writing superblocks and filesystem accounting information: done
ln -snf /root/buildroot/output/host/x86_64-buildroot-linux-uclibc/sysroot /root/buildroot/output/staging
>>> Executing post-image script board/qemu/post-image.sh
root@b218928410d1:~/buildroot#
(recommended) From outside the container:
cd /media/sarnobat/unmirrored/trash/buildroot-2021.12/docker-buildroot
scripts/run.sh /buildroot_output/images/start-qemu.sh
From inside container: root@b218928410d1: ~/buildroot# sh /buildroot_output/images/start-qemu.sh
run this to start it:
/buildroot_output/images/start-qemu.sh
/root/buildroot/output/images/start-qemu.sh
TODO: modify this for docker
qemu-system-x86_64 -kernel /boot/vmlinuz-4.15.0-133-generic -initrd /boot/initrd.img-4.15.0-133-generic
Starting network: udhcpc: started, v1.31.1
random: mktemp: uninitialized urandom read (6 bytes read)
udhcpc: sending discover
udhcpc: sending select for 10.0.2.15
udhcpc: lease of 10.0.2.15 obtained, lease time 86400
deleting routers
random: mktemp: uninitialized urandom read (6 bytes read)
adding dns 10.0.2.3
OK
Welcome to Buildroot
buildroot login:
# wget 'netgear.rohidekar.com'
SRIDHAR Connecting to netgear.rohidekar.com (73.222.175.43:80)
saving to 'index.html'
index.html 100% |********************************| 1718 0:00:00 ETA
'index.html' saved
The modified busybox seems to come from this native file:
/media/sarnobat/ebay/trash/docker/volumes/d02844a1aa32dcc42ab075b1c2f63f5b7a70673bcaf6606ae9bdb0198ca11dd6/_data/target/bin/busybox
132 docker images -a
133 docker image inspect f0f1e5b912da
Note: this won't allow you to change the source code, it just downloads a lot of precompiled binaries.
cd /media/sarnobat/unmirrored/trash/buildroot-2021.12/linux-kernel-module-cheat.2022-02
Then: https://github.com/cirosantilli/linux-kernel-module-cheat#25-docker-host-setup
- Note, install
docker.io.dockerdoesn't work, even though it should. - Do not confuse linux-kernel-module-cheat with linux-cheat. Ciro Santilli has a lot of great repositories and you need the kernel module one (linux-cheat is just for installing linux, not recompiling the source, I believe)
Ending log output:
mke2fs 1.45.6 (20-Mar-2020)
Creating regular file /root/lkmc/out.docker/buildroot/build/default/x86_64/images/rootfs.ext2
Creating filesystem with 262144 4k blocks and 65536 inodes
Filesystem UUID: 2d241e73-1deb-481c-b97d-4d7ce97c92c6
Superblock backups stored on blocks:
32768, 98304, 163840, 229376
Allocating group tables: done
Writing inode tables: done
Copying files into the device: done
Writing superblocks and filesystem accounting information: done
>>> Executing post-image script board/qemu/post-image.sh
+ /root/lkmc/out.docker/qemu/default/opt/qemu-img \
-T pr_manager_run,file=/dev/null \
convert \
-f raw \
-O qcow2 \
/root/lkmc/out.docker/buildroot/build/default/x86_64/images/rootfs.ext2 \
/root/lkmc/out.docker/buildroot/build/default/x86_64/images/rootfs.ext2.qcow2 \
;
time 02:25:03
with Buildroot it was much easier.
2021: Not Working on ubuntu 16 (which recently reached end of life) 2019: Worked on ubuntu 16 (when it was still supported)
See also /Volumes/git/sarnobat.git/yEd/2020/technology/linux_boot.graphml /Volumes/git/sarnobat.git/yEd/2020/technology/linux_buildroot_cheat_build_deps.graphml /Volumes/git/sarnobat.git/yEd/2020/technology/linux_buildroot_docker.graphml
- /Volumes/git/sarnobat.git/yEd/2020/technology/linux_call_graph.graphml
- /Volumes/git/sarnobat.git/yEd/2020/technology/minix_call_graph.graphml
- (mentions
head.S)
- (mentions
https://www.tamacom.com/tour/kernel/linux/S/39904.html#L474 https://unix.stackexchange.com/questions/139297/what-are-the-two-head-s-files-in-linux-source
Kernel launch (from busybox?):
./buildroot_output/build/linux-5.4.58/arch/x86/kernel/setup.c:885: printk(KERN_INFO "SRIDHAR Command line: %s\n", boot_command_line);
SRIDHAR Command line: rootwait root=/dev/vda console=tty1 console=ttyS0
./buildroot_output/build/linux-headers-5.4.58/init/main.c: pr_notice("SRIDHAR: Kernel command line: %s\n", boot_command_line);
SRIDHAR Kernel command line: rootwait root=/dev/vda console=tty1 console=ttyS0
init launch:
./buildroot_output/build/linux-5.4.58/init/main.c:1048: pr_info("SRIDHAR: Run %s as init process\n", init_filename);
SRIDHAR: Run /sbin/init as init process
- piggy.S
- vmlinux.c
Kernel boot parameters: start_qemu.sh
Unfortunately you can't put a prink statement in head64.c. It will change the size of it, corrupting the instructions in the boot sector. (but you can read about it in the "jump to main" section here: https://0xax.gitbooks.io/linux-insides/content/Booting/linux-bootstrap-1.html )
./buildroot_output/build/linux-5.4.58/arch/x86/kernel/head64.c: start_kernel();
SRIDHAR start_kernel() 9
./buildroot_output/build/linux-5.4.58/arch/x86/kernel/smpboot.c: pr_info("Allowing %d CPUs, %d hotplug CPUs\n",
./buildroot_output/build/linux-5.4.58/arch/x86/kernel/apic/apic.c: pr_info("APIC: Switch to symmetric I/O mode setup\n");
Thanks to these sources for helping me find some of this code:
- https://0xax.gitbooks.io/linux-insides/content/Booting/linux-bootstrap-1.html
- https://tldp.org/HOWTO/Linux-i386-Boot-Code-HOWTO/init_main.html
- https://www.oreilly.com/library/view/linux-device-drivers/0596000081/ch16s03.html
/Users/sarnobat/mwk.git/snippets/basic_clusters_still_need_human_sorting/code/snpt_1633771455105_0__linux_code_comprehension_1.mwk/Users/sarnobat/mwk.git/snippets/basic_clusters_still_need_human_sorting/code/snpt_1633771455134_0__linux_code_comprehension_2.mwk
antec Mon 14 February 2022 11:08PM> scripts/run.sh /buildroot_output/images/start-qemu.sh
docker run --rm -ti --volumes-from buildroot_output -v /media/sarnobat/unmirrored/trash/buildroot-2021.12/docker-buildroot/data:/root/buildroot/data -v /medt
VNC server running on 127.0.0.1:5900
SRIDHAR arch/x86/boot/main.c::main()
SRIDHAR init/main.c::start_kernel() Linux version 5.4.58 (root@5465dd08bf9e) (gcc version 9.3.0 (Buildroot 2020.08)) #20 SMP Thu Feb 17 06:51:32 UTC 2022
SRIDHAR arch/x86/kernel/setup.c::setup_arch() 1 Command line: rootwait root=/dev/vda console=tty1 console=ttyS0
x86/fpu: x87 FPU will use FXSAVE
BIOS-provided physical RAM map:
BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable
BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved
BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved
BIOS-e820: [mem 0x0000000000100000-0x0000000007fdcfff] usable
BIOS-e820: [mem 0x0000000007fdd000-0x0000000007ffffff] reserved
BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved
NX (Execute Disable) protection: active
SMBIOS 2.8 present.
DMI: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
last_pfn = 0x7fdd max_arch_pfn = 0x400000000
x86/PAT: Configuration [0-7]: WB WC UC- UC WB WP UC- WT
found SMP MP-table at [mem 0x000f5aa0-0x000f5aaf]
ACPI: Early table checksum verification disabled
ACPI: RSDP 0x00000000000F58C0 000014 (v00 BOCHS )
ACPI: RSDT 0x0000000007FE156F 000030 (v01 BOCHS BXPCRSDT 00000001 BXPC 00000001)
ACPI: FACP 0x0000000007FE144B 000074 (v01 BOCHS BXPCFACP 00000001 BXPC 00000001)
ACPI: DSDT 0x0000000007FE0040 00140B (v01 BOCHS BXPCDSDT 00000001 BXPC 00000001)
ACPI: FACS 0x0000000007FE0000 000040
ACPI: APIC 0x0000000007FE14BF 000078 (v01 BOCHS BXPCAPIC 00000001 BXPC 00000001)
ACPI: HPET 0x0000000007FE1537 000038 (v01 BOCHS BXPCHPET 00000001 BXPC 00000001)
Zone ranges:
DMA [mem 0x0000000000001000-0x0000000000ffffff]
DMA32 [mem 0x0000000001000000-0x0000000007fdcfff]
Normal empty
Movable zone start for each node
Early memory node ranges
node 0: [mem 0x0000000000001000-0x000000000009efff]
node 0: [mem 0x0000000000100000-0x0000000007fdcfff]
Zeroed struct page in unavailable ranges: 133 pages
Initmem setup node 0 [mem 0x0000000000001000-0x0000000007fdcfff]
ACPI: PM-Timer IO Port: 0x608
ACPI: LAPIC_NMI (acpi_id[0xff] dfl dfl lint[0x1])
IOAPIC[0]: apic_id 0, version 32, address 0xfec00000, GSI 0-23
ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl dfl)
ACPI: INT_SRC_OVR (bus 0 bus_irq 5 global_irq 5 high level)
ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
ACPI: INT_SRC_OVR (bus 0 bus_irq 10 global_irq 10 high level)
ACPI: INT_SRC_OVR (bus 0 bus_irq 11 global_irq 11 high level)
Using ACPI (MADT) for SMP configuration information
ACPI: HPET id: 0x8086a201 base: 0xfed00000
smpboot: Allowing 1 CPUs, 0 hotplug CPUs
[mem 0x08000000-0xfffbffff] available for PCI devices
Booting paravirtualized kernel on bare hardware
clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645519600211568 ns
SRIDHAR kernel/setup.c::setup_arch() 9
setup_percpu: NR_CPUS:64 nr_cpumask_bits:64 nr_cpu_ids:1 nr_node_ids:1
percpu: Embedded 41 pages/cpu s127256 r8192 d32488 u2097152
Built 1 zonelists, mobility grouping on. Total pages: 32102
SRIDHAR init/main.c start_kernel() Kernel command line: rootwait root=/dev/vda console=tty1 console=ttyS0
Dentry cache hash table entries: 16384 (order: 5, 131072 bytes, linear)
Inode-cache hash table entries: 8192 (order: 4, 65536 bytes, linear)
mem auto-init: stack:off, heap alloc:off, heap free:off
Memory: 113616K/130540K available (8195K kernel code, 446K rwdata, 1640K rodata, 876K init, 640K bss, 16924K reserved, 0K cma-reserved)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
rcu: Hierarchical RCU implementation.
rcu: RCU restricting CPUs from NR_CPUS=64 to nr_cpu_ids=1.
rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
NR_IRQS: 4352, nr_irqs: 48, preallocated irqs: 16
Console: colour VGA+ 80x25
printk: console [tty1] enabled
printk: console [ttyS0] enabled
ACPI: Core revision 20190816
clocksource: hpet: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604467 ns
APIC: Switch to symmetric I/O mode setup
..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
tsc: Unable to calibrate against PIT
tsc: using HPET reference calibration
tsc: Detected 2801.037 MHz processor
clocksource: tsc-early: mask: 0xffffffffffffffff max_cycles: 0x2860145f0a0, max_idle_ns: 440795343665 ns
Calibrating delay loop (skipped), value calculated using timer frequency.. 5602.07 BogoMIPS (lpj=11204148)
pid_max: default: 32768 minimum: 301
SRIDHAR init/main.c fork_init()
Mount-cache hash table entries: 512 (order: 0, 4096 bytes, linear)
Mountpoint-cache hash table entries: 512 (order: 0, 4096 bytes, linear)
SRIDHAR init/main.c 7
SRIDHAR init/main.c 7.5
SRIDHAR init/main.c 8
SRIDHAR init/main.c 8.1
Last level iTLB entries: 4KB 0, 2MB 0, 4MB 0
Last level dTLB entries: 4KB 0, 2MB 0, 4MB 0, 1GB 0
Spectre V1 : Mitigation: usercopy/swapgs barriers and __user pointer sanitization
Spectre V2 : Mitigation: Full AMD retpoline
Spectre V2 : Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch
Speculative Store Bypass: Vulnerable
Freeing SMP alternatives memory: 24K
SRIDHAR init/main.c 8.2
SRIDHAR init/main.c 8.3
SRIDHAR init/main.c 8.4
SRIDHAR init/main.c 8.5
SRIDHAR init/main.c rest_init() 0 - starting scheduler
SRIDHAR kernel_init() 1
kernel_init_freeable() 1
smpboot: CPU0: AMD QEMU Virtual CPU version 2.5+ (family: 0x6, model: 0x6, stepping: 0x3)
Performance Events: PMU not available due to virtualization, using software events only.
rcu: Hierarchical SRCU implementation.
smp: Bringing up secondary CPUs ...
smp: Brought up 1 node, 1 CPU
smpboot: Max logical packages: 1
smpboot: Total of 1 processors activated (5602.07 BogoMIPS)
devtmpfs: initialized
SRIDHAR init/main.c do_initcall_level() run level = 0 :: rootwait root=/dev/vda console=tty1 console=ttyS0
random: get_random_u32 called from bucket_table_alloc.isra.0+0x75/0x160 with crng_init=0
SRIDHAR init/main.c do_initcall_level() run level = 1 :: rootwait root=/dev/vda console=tty1 console=ttyS0
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns
futex hash table entries: 256 (order: 2, 16384 bytes, linear)
NET: Registered protocol family 16
SRIDHAR init/main.c do_initcall_level() run level = 2 :: rootwait root=/dev/vda console=tty1 console=ttyS0
cpuidle: using governor ladder
SRIDHAR init/main.c do_initcall_level() run level = 3 :: rootwait root=/dev/vda console=tty1 console=ttyS0
ACPI: bus type PCI registered
PCI: Using configuration type 1 for base access
SRIDHAR init/main.c do_initcall_level() run level = 4 :: rootwait root=/dev/vda console=tty1 console=ttyS0
ACPI: Added _OSI(Module Device)
ACPI: Added _OSI(Processor Device)
ACPI: Added _OSI(3.0 _SCP Extensions)
ACPI: Added _OSI(Processor Aggregator Device)
ACPI: Added _OSI(Linux-Dell-Video)
ACPI: Added _OSI(Linux-Lenovo-NV-HDMI-Audio)
ACPI: Added _OSI(Linux-HPI-Hybrid-Graphics)
ACPI: 1 ACPI AML tables successfully acquired and loaded
ACPI: Interpreter enabled
ACPI: (supports S0 S3 S5)
ACPI: Using IOAPIC for interrupt routing
PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug
ACPI: Enabled 2 GPEs in block 00 to 0F
ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])
acpi PNP0A03:00: _OSC: OS supports [Segments HPX-Type3]
acpi PNP0A03:00: fail to add MMCONFIG information, can't access extended PCI configuration space under this bridge.
PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7 window]
pci_bus 0000:00: root bus resource [io 0x0d00-0xffff window]
pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff window]
pci_bus 0000:00: root bus resource [mem 0x08000000-0xfebfffff window]
pci_bus 0000:00: root bus resource [mem 0x100000000-0x17fffffff window]
pci_bus 0000:00: root bus resource [bus 00-ff]
pci 0000:00:00.0: [8086:1237] type 00 class 0x060000
pci 0000:00:01.0: [8086:7000] type 00 class 0x060100
pci 0000:00:01.1: [8086:7010] type 00 class 0x010180
pci 0000:00:01.1: reg 0x20: [io 0xc0a0-0xc0af]
pci 0000:00:01.1: legacy IDE quirk: reg 0x10: [io 0x01f0-0x01f7]
pci 0000:00:01.1: legacy IDE quirk: reg 0x14: [io 0x03f6]
pci 0000:00:01.1: legacy IDE quirk: reg 0x18: [io 0x0170-0x0177]
pci 0000:00:01.1: legacy IDE quirk: reg 0x1c: [io 0x0376]
pci 0000:00:01.3: [8086:7113] type 00 class 0x068000
pci 0000:00:01.3: quirk: [io 0x0600-0x063f] claimed by PIIX4 ACPI
pci 0000:00:01.3: quirk: [io 0x0700-0x070f] claimed by PIIX4 SMB
pci 0000:00:02.0: [1234:1111] type 00 class 0x030000
pci 0000:00:02.0: reg 0x10: [mem 0xfd000000-0xfdffffff pref]
pci 0000:00:02.0: reg 0x18: [mem 0xfebd0000-0xfebd0fff]
pci 0000:00:02.0: reg 0x30: [mem 0xfebc0000-0xfebcffff pref]
pci 0000:00:03.0: [1af4:1000] type 00 class 0x020000
pci 0000:00:03.0: reg 0x10: [io 0xc080-0xc09f]
pci 0000:00:03.0: reg 0x14: [mem 0xfebd1000-0xfebd1fff]
pci 0000:00:03.0: reg 0x20: [mem 0xfe000000-0xfe003fff 64bit pref]
pci 0000:00:03.0: reg 0x30: [mem 0xfeb80000-0xfebbffff pref]
pci 0000:00:04.0: [1af4:1001] type 00 class 0x010000
pci 0000:00:04.0: reg 0x10: [io 0xc000-0xc07f]
pci 0000:00:04.0: reg 0x14: [mem 0xfebd2000-0xfebd2fff]
pci 0000:00:04.0: reg 0x20: [mem 0xfe004000-0xfe007fff 64bit pref]
ACPI: PCI Interrupt Link [LNKA] (IRQs 5 *10 11)
ACPI: PCI Interrupt Link [LNKB] (IRQs 5 *10 11)
ACPI: PCI Interrupt Link [LNKC] (IRQs 5 10 *11)
ACPI: PCI Interrupt Link [LNKD] (IRQs 5 10 *11)
ACPI: PCI Interrupt Link [LNKS] (IRQs *9)
pci 0000:00:02.0: vgaarb: setting as boot VGA device
pci 0000:00:02.0: vgaarb: VGA device added: decodes=io+mem,owns=io+mem,locks=none
pci 0000:00:02.0: vgaarb: bridge control possible
vgaarb: loaded
SCSI subsystem initialized
ACPI: bus type USB registered
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
Advanced Linux Sound Architecture Driver Initialized.
PCI: Using ACPI for IRQ routing
SRIDHAR init/main.c do_initcall_level() run level = 5 :: rootwait root=/dev/vda console=tty1 console=ttyS0
clocksource: Switched to clocksource tsc-early
pnp: PnP ACPI init
pnp: PnP ACPI: found 6 devices
thermal_sys: Registered thermal governor 'step_wise'
thermal_sys: Registered thermal governor 'user_space'
clocksource: acpi_pm: mask: 0xffffff max_cycles: 0xffffff, max_idle_ns: 2085701024 ns
pci_bus 0000:00: resource 4 [io 0x0000-0x0cf7 window]
pci_bus 0000:00: resource 5 [io 0x0d00-0xffff window]
pci_bus 0000:00: resource 6 [mem 0x000a0000-0x000bffff window]
pci_bus 0000:00: resource 7 [mem 0x08000000-0xfebfffff window]
pci_bus 0000:00: resource 8 [mem 0x100000000-0x17fffffff window]
NET: Registered protocol family 2
tcp_listen_portaddr_hash hash table entries: 256 (order: 0, 4096 bytes, linear)
TCP established hash table entries: 1024 (order: 1, 8192 bytes, linear)
TCP bind hash table entries: 1024 (order: 2, 16384 bytes, linear)
TCP: Hash tables configured (established 1024 bind 1024)
UDP hash table entries: 256 (order: 1, 8192 bytes, linear)
UDP-Lite hash table entries: 256 (order: 1, 8192 bytes, linear)
NET: Registered protocol family 1
pci 0000:00:01.0: PIIX3: Enabling Passive Release
pci 0000:00:00.0: Limiting direct PCI/PCI transfers
pci 0000:00:01.0: Activating ISA DMA hang workarounds
pci 0000:00:02.0: Video device with shadowed ROM at [mem 0x000c0000-0x000dffff]
PCI: CLS 0 bytes, default 64
SRIDHAR init/main.c do_initcall_level() run level = 6 :: rootwait root=/dev/vda console=tty1 console=ttyS0
workingset: timestamp_bits=62 max_order=15 bucket_order=0
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254)
io scheduler mq-deadline registered
io scheduler kyber registered
input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input0
ACPI: Power Button [PWRF]
PCI Interrupt Link [LNKC] enabled at IRQ 11
PCI Interrupt Link [LNKD] enabled at IRQ 10
Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
00:05: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
bochs-drm 0000:00:02.0: remove_conflicting_pci_framebuffers: bar 0: 0xfd000000 -> 0xfdffffff
bochs-drm 0000:00:02.0: remove_conflicting_pci_framebuffers: bar 2: 0xfebd0000 -> 0xfebd0fff
bochs-drm 0000:00:02.0: vgaarb: deactivate vga console
Console: switching to colour dummy device 80x25
[drm] Found bochs VGA, ID 0xb0c0.
[drm] Framebuffer size 16384 kB @ 0xfd000000, mmio @ 0xfebd0000.
[TTM] Zone kernel: Available graphics memory: 56820 KiB
[TTM] Initializing pool allocator
[TTM] Initializing DMA pool allocator
[drm] Found EDID data blob.
[drm] Initialized bochs-drm 1.0.0 20130925 for 0000:00:02.0 on minor 0
fbcon: bochs-drmdrmfb (fb0) is primary device
Console: switching to colour frame buffer device 128x48
bochs-drm 0000:00:02.0: fb0: bochs-drmdrmfb frame buffer device
virtio_blk virtio1: [vda] 122880 512-byte logical blocks (62.9 MB/60.0 MiB)
scsi host0: ata_piix
scsi host1: ata_piix
ata1: PATA max MWDMA2 cmd 0x1f0 ctl 0x3f6 bmdma 0xc0a0 irq 14
ata2: PATA max MWDMA2 cmd 0x170 ctl 0x376 bmdma 0xc0a8 irq 15
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
ehci-pci: EHCI PCI platform driver
uhci_hcd: USB Universal Host Controller Interface driver
usbcore: registered new interface driver usb-storage
i8042: PNP: PS/2 Controller [PNP0303:KBD,PNP0f13:MOU] at 0x60,0x64 irq 1,12
serio: i8042 KBD port at 0x60,0x64 irq 1
serio: i8042 AUX port at 0x60,0x64 irq 12
tsc: Refined TSC clocksource calibration: 2806.295 MHz
clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x28737b6f6bd, max_idle_ns: 440795264818 ns
clocksource: Switched to clocksource tsc
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
input: AT Translated Set 2 keyboard as /devices/platform/i8042/serio0/input/input1
NET: Registered protocol family 10
Segment Routing with IPv6
sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
NET: Registered protocol family 17
SRIDHAR init/main.c do_initcall_level() run level = 7 :: rootwait root=/dev/vda console=tty1 console=ttyS0
IPI shorthand broadcast: enabled
sched_clock: Marking stable (1977305344, -46258675)->(1947468641, -16421972)
ALSA device list:
No soundcards found.
ata2.00: ATAPI: QEMU DVD-ROM, 2.5+, max UDMA/100
scsi 1:0:0:0: CD-ROM QEMU QEMU DVD-ROM 2.5+ PQ: 0 ANSI: 5
input: ImExPS/2 Generic Explorer Mouse as /devices/platform/i8042/serio1/input/input3
EXT4-fs (vda): mounting ext2 file system using the ext4 subsystem
EXT4-fs (vda): mounted filesystem without journal. Opts: (null)
VFS: Mounted root (ext2 filesystem) readonly on device 254:0.
devtmpfs: mounted
SRIDHAR kernel_init_freeable() 9
Freeing unused kernel image memory: 876K
Write protecting the kernel read-only data: 12288k
Freeing unused kernel image memory: 2016K
Freeing unused kernel image memory: 408K
SRIDHAR kernel_init() 5
SRIDHAR kernel_init() 7
SRIDHAR kernel_init() 8
SRIDHAR: Run /sbin/init as init process
random: fast init done
SRIDHAR busybox/init/init.c init_main()
SRIDHAR busybox/init/init.c new_init_action() - /bin/mount -t proc proc /proc
SRIDHAR busybox/init/init.c new_init_action() - /bin/mount -o remount,rw /
SRIDHAR busybox/init/init.c new_init_action() - /bin/mkdir -p /dev/pts /dev/shm
SRIDHAR busybox/init/init.c new_init_action() - /bin/mount -a
SRIDHAR busybox/init/init.c new_init_action() - /sbin/swapon -a
SRIDHAR busybox/init/init.c new_init_action() - /bin/ln -sf /proc/self/fd /dev/fd
SRIDHAR busybox/init/init.c new_init_action() - /bin/ln -sf /proc/self/fd/0 /dev/stdin
SRIDHAR busybox/init/init.c new_init_action() - /bin/ln -sf /proc/self/fd/1 /dev/stdout
SRIDHAR busybox/init/init.c new_init_action() - /bin/ln -sf /proc/self/fd/2 /dev/stderr
SRIDHAR busybox/init/init.c new_init_action() - /bin/hostname -F /etc/hostname
SRIDHAR busybox/init/init.c new_init_action() - /etc/init.d/rcS
SRIDHAR busybox/init/init.c new_init_action() - /sbin/getty -L console 0 vt100
SRIDHAR busybox/init/init.c new_init_action() - /sbin/getty -L tty1 0 vt100
SRIDHAR busybox/init/init.c new_init_action() - /etc/init.d/rcK
SRIDHAR busybox/init/init.c new_init_action() - /sbin/swapoff -a
SRIDHAR busybox/init/init.c new_init_action() - /bin/umount -a -r
SRIDHAR busybox/init/init.c init_main() running SYSINIT
EXT4-fs (vda): re-mounted. Opts: (null)
ext2 filesystem being remounted at / supports timestamps until 2038 (0x7fffffff)
Starting syslogd: OK
Starting klogd: OK
Running sysctl: OK
Saving random seed: random: dd: uninitialized urandom read (512 bytes read)
OK
Starting network: udhcpc: started, v1.31.1
random: mktemp: uninitialized urandom read (6 bytes read)
udhcpc: sending discover
udhcpc: sending select for 10.0.2.15
udhcpc: lease of 10.0.2.15 obtained, lease time 86400
deleting routers
random: mktemp: uninitialized urandom read (6 bytes read)
adding dns 10.0.2.3
OK
Welcome to Buildroot
buildroot login:
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/cli_function.py:152: print(' SRIDHAR cli_function::CliFunction::_do_main()')
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/cli_function.py:240: print(' SRIDHAR cli_noexit')
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/cli_function.py:261: print('SRIDHAR cli_function::CliFunction::cli_noexit()')
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/common.py:45:print(' SRIDHAR consts[root_dir] = ' + consts['root_dir'])
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/common.py:749: print(' SRIDHAR: common::LkmcCliFunction::_init_env() env[buildroot_rootfs_raw_file] = ' + env['buildroot_rootfs_raw_file'])
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/common.py:1314: print(' SRIDHAR common::LkmcCliFunction::main()')
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/common.py:1367: print(' SRIDHAR raw_to_qcow2()')
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/drivers/net/ethernet/intel/fm10k/fm10k_pci.c:1836:printk("SRIDHAR fm10k_up() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/drivers/staging/wilc1000/wilc_wfi_cfgoperations.c:266:printf("SRIDHAR connect() - begin 2\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/drivers/block/xen-blkback/xenbus.c:839:printf("SRIDHAR connect()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/tcp_output.c:1027:printk("SRIDHAR __tcp_transmit_skb() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/tcp_output.c:1129:printk("SRIDHAR __tcp_transmit_skb() - send_check\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/tcp_output.c:2331:printk("SRIDHAR tcp_write_xmit() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/tcp_ipv4.c:620:printk("SRIDHAR __tcp_v4_send_check()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/tcp_ipv4.c:1414:printk("SRIDHAR tcp_v4_syn_recv_sock() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/tcp_ipv4.c:2605:printk("SRIDHAR tcp_sk_init() - begin");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/af_inet.c:609:/*printf("SRIDHAR __inet_stream_connect()\n");*/
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/af_inet.c:610:/*fprintf("SRIDHAR __inet_stream_connect()\n");*/
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/af_inet.c:611:printk("SRIDHAR __inet_stream_connect() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/ip_output.c:101:printk("SRIDHAR __ip_local_out() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/ip_output.c:122:printk("SRIDHAR ip_local_out() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/ip_output.c:446:printk("SRIDHAR __ip_queue_xmit() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/ipv4/ip_output.c:1390:printk("SRIDHAR __ip_make_skb() - begin\b");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/socket.c:1821:printk("SRIDHAR __sys_connect()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/socket.c:1845: printk("SRIDHAR SYSCALL_DEFINE3()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/socket.c:2317:printk("SRIDHAR __sys_sendmsg()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/socket.c:2705:printk("SRIDHAR socket.c::SYSCALL_DEFINE2()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/netfilter/core.c:270: printk("SRIDHAR nf_hook_entry_head() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/net/compat.c:724:printk("SRIDHAR COMPAT_SYSCALL_DEFINE2()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/tools/usb/usbip/src/usbipd.c:430:printf("SRIDHAR do_getaddrinfo() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/include/linux/netfilter.h:216:printk("SRIDHAR nf_hook() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/include/net/ip.h:198: printk("SRIDHAR ip_queue_xmit()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/include/net/l3mdev.h:178:printk("SRIDHAR l3mdev_l3_out() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/linux/include/net/l3mdev.h:194: printk("SRIDHAR l3mdev_ip_out() - begin\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/qemu/roms/edk2/StdLib/BsdSocketLib/connect.c:69: printf("SRIDHAR connect() - begin 3\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/submodules/qemu/roms/edk2/AppPkg/Applications/Python/Python-2.7.2/Modules/getaddrinfo.c:247:printf("SRIDHAR getaddrinfo()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/userland/posix/wget.c:30:printf("SRIDHAR wget\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/socket.c:1821:printk("SRIDHAR __sys_connect()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/socket.c:1845: printk("SRIDHAR SYSCALL_DEFINE3()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/socket.c:2317:printk("SRIDHAR __sys_sendmsg()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/socket.c:2705:printk("SRIDHAR socket.c::SYSCALL_DEFINE2()\n");
/media/sarnobat/cadet/trash/buildroot/buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat/shell_helpers.py:368: print(' SRIDHAR cmd = ' + ' '.join(cmd))
At run level 1, the following are running:
systemd─┬─3*[dbus-daemon]
├─sshd───sshd───zsh───pstree
├─systemd─┬─(sd-pam)
│ ├─dbus-daemon
│ ├─gvfs-udisks2-vo───2*[{gvfs-udisks2-vo}]
│ ├─gvfsd───3*[{gvfsd}]
│ ├─gvfsd-fuse───5*[{gvfsd-fuse}]
│ ├─pulseaudio───3*[{pulseaudio}]
│ └─tracker-miner-f───3*[{tracker-miner-f}]
├─systemd-journal
├─systemd-sulogin───sulogin
├─systemd-timesyn───{systemd-timesyn}
└─systemd-udevd
fileserver2017 Mon 21 February 2022 8:19PM> ls --color -lrhsSA /etc/rc1.d/
total 0
0 lrwxrwxrwx 1 root root 13 Jan 9 19:31 K01ufw -> ../init.d/ufw
0 lrwxrwxrwx 1 root root 14 Jan 9 19:31 K01gdm3 -> ../init.d/gdm3
0 lrwxrwxrwx 1 root root 14 Jan 9 19:31 K01cups -> ../init.d/cups
0 lrwxrwxrwx 1 root root 15 Jan 9 19:31 K01uuidd -> ../init.d/uuidd
0 lrwxrwxrwx 1 root root 15 Jan 9 19:31 K01saned -> ../init.d/saned
0 lrwxrwxrwx 1 root root 17 Jan 9 19:31 K01rsyslog -> ../init.d/rsyslog
0 lrwxrwxrwx 1 root root 17 Jan 9 20:34 K01rpcbind -> ../init.d/rpcbind
0 lrwxrwxrwx 1 root root 17 Jan 9 19:31 K01openvpn -> ../init.d/openvpn
0 lrwxrwxrwx 1 root root 18 Jan 9 19:31 K01whoopsie -> ../init.d/whoopsie
0 lrwxrwxrwx 1 root root 19 Jan 9 19:31 K01bluetooth -> ../init.d/bluetooth
0 lrwxrwxrwx 1 root root 20 Jan 9 21:13 K01ubuntu-fan -> ../init.d/ubuntu-fan
0 lrwxrwxrwx 1 root root 20 Jan 9 20:34 K01nfs-common -> ../init.d/nfs-common
0 lrwxrwxrwx 1 root root 20 Jan 9 19:31 K01kerneloops -> ../init.d/kerneloops
0 lrwxrwxrwx 1 root root 20 Jan 9 19:31 K01irqbalance -> ../init.d/irqbalance
0 lrwxrwxrwx 1 root root 20 Jan 9 19:31 K01alsa-utils -> ../init.d/alsa-utils
0 lrwxrwxrwx 1 root root 22 Jan 9 19:31 K01cups-browsed -> ../init.d/cups-browsed
0 lrwxrwxrwx 1 root root 22 Jan 9 19:31 K01avahi-daemon -> ../init.d/avahi-daemon
0 lrwxrwxrwx 1 root root 23 Jan 9 19:31 K01spice-vdagent -> ../init.d/spice-vdagent
0 lrwxrwxrwx 1 root root 23 Jan 9 19:31 K01lvm2-lvmpolld -> ../init.d/lvm2-lvmpolld
0 lrwxrwxrwx 1 root root 27 Jan 9 19:31 K01speech-dispatcher -> ../init.d/speech-dispatcher
0 lrwxrwxrwx 1 root root 27 Jan 9 20:34 K01nfs-kernel-server -> ../init.d/nfs-kernel-server
0 lrwxrwxrwx 1 root root 37 Jan 9 19:31 K01pulseaudio-enable-autospawn -> ../init.d/pulseaudio-enable-autospawn
https://github.com/cirosantilli/linux-kernel-module-cheat
- 2022-02: not working with ubuntu 20. I guess it was only tested on Ubuntu 18.
- 2021-12-31: not working? Maybe I need to try on a version of Ubuntu that is still supported.
- 2021: Not Working on ubuntu 16 (which recently reached end of life)
- 2019: Worked on ubuntu 16 (when it was still supported)
Kernel:
# https://github.com/cirosantilli/linux-kernel-module-cheat#qemu-buildroot-setup-getting-started
./setup
# add deb-src repo: https://askubuntu.com/a/857433/126830
unset PERL_MM_OPT && PATH=/bin/:/usr/local/bin:/usr/bin:/sbin ./build --download-dependencies qemu-buildroot | tee /tmp/buildrootcheat.log
run
Inside guest
ifup -a
Busybox:
~~There's no easy to rebuild packages like wget after adding print statements, because buildroot will download the source again and ovwerite it (I think). You'll have to drop back to Buildroot non-cheat version.
unset PERL_MM_OPT && PATH=/bin/:/usr/local/bin:/usr/bin:/sbin ./build-buildroot -- busybox-rebuild
Other useful things to note:
--ctrl-c-host- there's a graphml diagram
Kernel (https://cirosantilli.com/linux-kernel-module-cheat/#gdb-step-debug-kernel-post-boot):
./run
./run-gdb
fileserver2017 Thu 30 December 2021 3:27PM> cd /media/sarnobat/cadet/trash/buildroot && ls -l /media/sarnobat/cadet/trash/buildroot
total 6208
-rw-rw-r-- 1 sarnobat sarnobat 6342933 Oct 3 2019 buildroot-2019.02.6.tar.gz
drwxrwxr-x 16 sarnobat sarnobat 4096 Nov 11 2019 buildroot-arm.2019.02.6
drwxrwxr-x 3 sarnobat sarnobat 4096 Oct 27 2019 buildroot-arm.2019.02.6.cheat
lrwxrwxrwx 1 sarnobat sarnobat 55 Nov 21 2019 buildroot-cheat -> buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat
drwxrwxr-x 17 sarnobat sarnobat 4096 Nov 6 2019 buildroot-x86.2019-11-06.git
lrwxrwxrwx 1 sarnobat sarnobat 55 Nov 21 2019 cheat -> buildroot-arm.2019.02.6.cheat/linux-kernel-module-cheat
Make sure you get a RELEASE, not the latest source.
make
qemu-system-x86_64 -kernel /boot/vmlinuz-5.3.0 -initrd /boot/initrd.img-5.3.0