Linux
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allwinner a10
The Allwinner A10 CPU has been developed in, and is sold in, the People's Republic of China. Its mass-volume price is around $7, yet it is a 400-pin highly feature-rich 1.2ghz ARM Cortex A8 with a MALI400 GPU. It has the distinction of having the highest bang-per-buck ratio of any SoC available at the time of writing, by quite a margin. Its price and features is causing massive disruption of the tablet market in China (a minor recession was caused by widespread cancellation of prior committments to other SoCs!)
Inside the /proc directory, you’ll see two types of content — numbered directories, and system information files. /proc is not a real file system, it is a virtual file system. For example, if you do ls -l /proc/stat, you’ll notice that it has a size of 0 bytes, but if you do “cat /proc/stat”, you’ll see some content inside the file. Do a ls -l /proc, and you’ll see lot of directories with just numbers. These numbers represents the process ids, the files inside this numbered directory corresponds to the process with that particular PID.
Explore Linux /proc File System (/proc directories, /proc files)
As USB is designed for hotplugging of devices, the operating system also needs a mechanism that dynamically creates devices (device files) for the devices currently connected and switched on. The operating system has to determine which users may access a device dynamically. As the operating system cannot determine this by itself, there have to be some helper applications.
4.3. Setting up permissions for USB ports
This subdirectory contains information about all IDE devices of which the kernel is aware. There is one subdirectory for each IDE controller, the file drivers and a link for each IDE device, pointing to the device directory in the controller-specific subtree. The file drivers contains general information about the drivers used for the IDE devices. More detailed information can be found in the controller-specific subdirectories. These are named ide0, ide1 and so on.
/proc
The proc file system is a pseudo-file system which is used as an interface to kernel data structures. It is commonly mounted at /proc . Most of it is read- only, but some files allow kernel variables to be changed.
proc(5) - Linux manual page
Serial Drivers Creating
Advice for boot loader authors
Serial console support in a boot loader is very useful. Thank you for supporting it. The boot loader should support the 8250A UART and its programming-compatible 82510 , 16450 , 16550 and 16750 descendants. The serial chip used in the IBM PC/XT , the 8250 (no A), and its 8250B descendant need not be supported. The 8250A data sheet is 82C50A CMOS Asynchronous Communications Element and is updated by Intel's errata 82510 PC Software Compatibility .
Advice for BIOS authors
Thank you for adding support for remote operations to your BIOS . A few points will maximize the benefits of that support, most of them are listed in Section F.1 . Keep the user interface simple.
A conventional computer operating system usually segregates virtual memory into kernel space and user space . Kernel space is strictly reserved for running the kernel , kernel extensions, and most device drivers . In contrast, user space is the memory area where all user mode applications work and this memory can be swapped out when necessary. Similarly, the term userland refers to all application software that runs in user space. [ 1 ] Userland usually refers to the various programs and libraries that the operating system uses to interact with the kernel: software that performs input/output , manipulates file system objects, etc. Each user space process normally runs in its own virtual memory space, and, unless explicitly requested, cannot access the memory of other processes.
User space - Wikipedia, the free encyclopedia
