I’d try: (gdb) target remote localhost:1234 (gdb) continue Using the ‘-s’ option makes qemu listen on port tcp::1234, which you can connect to as localhost:1234 if you are on the same machine. Qemu’s ‘-S’ option makes Qemu stop execution until you give the continue command. Best thing would probably be to have a look at … Read more
if the full message is: kernel panic – not syncing: Attempted to kill inint ! PId: 1, comm: init not tainted 2.6.32.-279-5.2.e16.x86_64 #1 then you should have disabled selinux and after that you have rebooted the system. The easier way is to use a live OS and re-enable it vim /etc/selinux/config … SELINUX=enforcing … Second … Read more
The reason that documentation is scarce is that it’s an area that’s quite architecture-dependent. The code is really the best documentation – for example, the THREAD_SIZE macro defines the (architecture-dependent) per-thread kernel stack size. The stacks are allocated in alloc_thread_stack_node(). The stack pointer in the struct task_struct is updated in dup_task_struct(), which is called as … Read more
Long story short: the probe() function of the driver is called as a result of calling the register_driver for that specific bus. More precisely, it’s called by the probe() of that bus_type structure. In your case: i2c_bus_type. Here’s the call chain in your I2C case: i2c_register_driver driver_register bus_add_driver driver_attach __driver_attach (for your device) driver_probe_device really_probe … Read more
Memory-mapped I/O allows the CPU to control hardware by reading and writing specific memory addresses. Usually, this would be used for low-bandwidth operations such as changing control bits. DMA allows hardware to directly read and write memory without involving the CPU. Usually, this would be used for high-bandwidth operations such as disk I/O or camera … Read more
1) By default, perf stat shows task-clock, and does not show cpu-clock. Therefore we can tell task-clock was expected to be much more useful. 2) cpu-clock was simply broken, and has not been fixed for many years. It is best to ignore it. It was intended that cpu-clock of sleep 1 would show about 1 … Read more
Start with these: Kernel Bugs involving typo. (Search everyday until you find something promising). Search that bug database with keywords like “comment”, “typo”, “documentation”, “minor bug”, etc. Also, search under the category Documentation here. Learn the process first. Then, attempt to contribute something significant.
Your references are good but lack a definition of what is a platform device. There is one on LWN. What we can learn from this page: Platform devices are inherently not discoverable, i.e. the hardware cannot say “Hey! I’m present!” to the software. Typical examples are i2c devices, kernel/Documentation/i2c/instantiating-devices states: Unlike PCI or USB devices, … Read more
I assume, this refers to the same as the (y,n,m) prompt when running make config; in that case it would be “module”. Note that compiling Unix domain sockets (CONFIG_UNIX) as module is probably not a good idea. A lot of system components and programs depend on them, and some services might fail to start up … Read more