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Month: November 2017

Kernel Bootup Page Table Initialize Process(x86_64)

Kernel Bootup Page Table Initialize Process(x86_64)

This article will provide detailed information about the kernel bootup page table setup. In a brief view, the kernel setup page table in three steps: Setup the 4GB identity mapping Setup 64bit mode page table early_top_pgt Setup 64bit mode page table init_top_pgt The last two steps are both higher mapping: Map the 512MB physical address to virtual address 0xffff80000000 – 0xffff80000000 + 512MB. Next, we will talk about the details. We will use the 4.14 version code to explain the process….

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Kernel Driver btusb Overview

Kernel Driver btusb Overview

Function btusb_probe btusb_probe is use for hot plug-in for bluetooth usb generic controller, here will explain the function in detail. First is an interface check mechanism This special condition is used for supporting apple Macbook 12,8 (2015 early). According to the normal specification, the main interface for USB is 0, and audio (isochronous) is 1, but apple made a change on it, changing the main interface to 2 and audio to 3. The “bInterfaceNumber !=2 ” is for checking hardware…

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