ASUS C302CA Chromebook 安装 Linux 和 Windows

图源：@山桂贰 87141455

最近在咸鱼上淘到了一个二手的华硕 Chromebook（具体型号是 ASUS C302CA）。四核 M3-6Y30 + 8G 运行内存+ 32G eMMC 存储 + 12.5 寸触摸屏，虽然机身有少量磕碰，笔记本的转折铰链也有问题，但 800 元的价格着实实惠。

机器寄过来的时候依然是原装系统（Power Wash 过的 Chrome OS）。写个文章记录一将 OS 从 Chrome OS 换成 Manjaro 和 Windows 10 的过程。

拆写保护（WP）螺丝

Chromebook 的 BIOS 都是为了配合 Chrome OS 而特殊定做的，因此无法用来启动其他操作系统，没有 BIOS 设置界面，也无法升级 BIOS。但是可能是出于修理和防止可能的 BIOS 紧急固件更新，制造商仍然允许使用者解除 BIOS 的写入保护。常见的保护方式在 Chromium Projects Wiki 里有详细说明：

Application Processor (AP) Firmware

AP firmware (also known as “SOC firmware”, “host firmware”, “main firmware” or even “BIOS”) typically resides on a SPI ROM. Protection registers on the SPI ROM are programmed to protect the read-only region, and these registers normally cannot be modified while the SPI ROM WP (write protect) pin is asserted. This pin is asserted through various physical means (see below), but with effort, users can unprotect devices they own.

Embedded Controller (EC) Firmware

The Chrome OS Embedded Controller (EC) typically has a WP input pin driven by the same hardware that generates SOC firmware write protect. While this pin is asserted, certain debug features (eg. arbitrary I2C access through host commands) are locked out. Some ECs load code from external storage, and for these ECs, RO protection works similar to SOC firmware RO protection (WP pin is asserted to EC SPI ROM). Other ECs use internal flash, and these ECs emulate SPI ROM protection registers, disabling write access to certain regions while the WP pin is asserted.