Translate Chapter 5 and modify the source file format (#187)

* Translation Chapter 05

* Modify RPi3 and RPi4 unified formats
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# 教程 05 - 驱动程序: GPIO和UART
## tl;dr
- 添加了用于真实`UART`和`GPIO`控制器的驱动程序。
- **我们将首次能够在真实硬件上运行代码** (请向下滚动查看说明)。
## 简介
在上一篇教程中,我们启用了全局安全变量,为添加第一个真实设备驱动程序奠定了基础。
我们放弃了神奇的QEMU控制台并引入了一个`驱动程序管理器`,允许`BSP`将设备驱动程序注册到`内核`中。
## 驱动程序管理器
第一步是向内核添加一个`driver subsystem`。相应的代码将位于`src/driver.rs`中。
该子系统引入了`interface::DeviceDriver`,这是每个设备驱动程序都需要实现的通用特征,并为内核所知。
在同一文件中实例化的全局`DRIVER_MANAGER`实例(类型为`DriverManager`)作为一个中央实体,可以被调用来管理内核中的所有设备驱动程序。
例如,通过使用全局可访问的`crate::driver::driver_manager().register_driver(...)`,任何代码都可以注册一个实现了`interface::DeviceDriver`特征的具有静态生命周期的对象。
在内核初始化期间,调用`crate::driver::driver_manager().init_drivers(...)`将使驱动程序管理器遍历所有已注册的驱动程序,
并启动它们的初始化,并执行可选的`post-init callback`,该回调可以与驱动程序一起注册。
例如,此机制用于在`UART`驱动程序初始化后将其切换为主系统控制台的驱动程序。
## BSP驱动程序实现
在`src/bsp/raspberrypi/driver.rs`中,函数`init()`负责注册`UART`和`GPIO`驱动程序。
因此,在内核初始化期间,按照以下来自`main.rs`的代码,正确的顺序是:
i首先初始化BSP驱动程序子系统然后ii调用`driver_manager()`。
```rust
unsafe fn kernel_init() -> ! {
// Initialize the BSP driver subsystem.
if let Err(x) = bsp::driver::init() {
panic!("Error initializing BSP driver subsystem: {}", x);
}
// Initialize all device drivers.
driver::driver_manager().init_drivers();
// println! is usable from here on.
```
驱动程序本身存储在`src/bsp/device_driver`中,并且可以在不同的`BSP`之间重复使用
在这些教程中添加的第一个驱动程序是`PL011Uart`驱动程序:它实现了`console::interface::*`特征,并且从现在开始用作主系统控制台。
第二个驱动程序是`GPIO`驱动程序,它根据需要将`RPii's`的`UART`映射(即将来自`SoC`内部的信号路由到实际的硬件引脚)。
请注意,`GPIO`驱动程序区分**RPi 3**和**RPi 4**。它们的硬件不同,因此我们必须在软件中进行适配。
现在,`BSP`还包含了一个内存映射表,位于`src/bsp/raspberrypi/memory.rs`中。它提供了树莓派的`MMIO`地址,
`BSP`使用这些地址来实例化相应的设备驱动程序,以便驱动程序代码知道在内存中找到设备的寄存器的位置。
## SD卡启动
由于我们现在有了真实的`UART`输出,我们可以在真实的硬件上运行代码。
由于前面提到的`GPIO`驱动程序的差异,构建过程在**RPi 3**和**RPi 4**之间有所区别。
默认情况下,所有的`Makefile`目标都将为**RPi 3**构建。
为了**RPi 4**构建,需要在每个目标前加上`BSP=rpi4`。例如:
```console
$ BSP=rpi4 make
$ BSP=rpi4 make doc
```
不幸的是QEMU目前还不支持**RPi 4**,因此`BSP=rpi4 make qemu`无法工作。
**准备SD卡的一些步骤在RPi3和RPi4之间有所不同请在以下操作中小心。**
### 通用步骤
1. 创建一个名为`boot`的`FAT32`分区。
2. 在SD卡上生成一个名为`config.txt`的文件,并将以下内容写入其中:
```txt
arm_64bit=1
init_uart_clock=48000000
```
### RPi 3
3. 从[Raspberry Pi firmware repo](https://github.com/raspberrypi/firmware/tree/master/boot)中将以下文件复制到SD卡上
- [bootcode.bin](https://github.com/raspberrypi/firmware/raw/master/boot/bootcode.bin)
- [fixup.dat](https://github.com/raspberrypi/firmware/raw/master/boot/fixup.dat)
- [start.elf](https://github.com/raspberrypi/firmware/raw/master/boot/start.elf)
4. 运行`make`命令。
### RPi 4
3. 从[Raspberry Pi firmware repo](https://github.com/raspberrypi/firmware/tree/master/boot)中将以下文件复制到SD卡上
- [fixup4.dat](https://github.com/raspberrypi/firmware/raw/master/boot/fixup4.dat)
- [start4.elf](https://github.com/raspberrypi/firmware/raw/master/boot/start4.elf)
- [bcm2711-rpi-4-b.dtb](https://github.com/raspberrypi/firmware/raw/master/boot/bcm2711-rpi-4-b.dtb)
4. 运行`BSP=rpi4 make`命令。
_**注意**: 如果在您的RPi4上无法正常工作请尝试将`start4.elf`重命名为`start.elf` (不带4)
并复制到SD卡上。_
### 再次通用步骤
5. 将`kernel8.img`复制到SD卡上并将SD卡插入RPi。
6. 运行`miniterm` target在主机上打开UART设备
```console
$ make miniterm
```
> ❗ **注意**: `Miniterm`假设默认的串行设备名称为`/dev/ttyUSB0`。Depending on your
> 根据您的主机操作系统,设备名称可能会有所不同。例如,在`macOS`上,它可能是
> `/dev/tty.usbserial-0001`之类的。在这种情况下,请明确提供设备名称:
```console
$ DEV_SERIAL=/dev/tty.usbserial-0001 make miniterm
```
7. 将USB串口连接到主机PC。
- 请参考[top-level README](../README.md#-usb-serial-output)中的接线图。
- **注意**: TX发送线连接到RX接收引脚。
- 确保您**没有**连接USB串口的电源引脚只连接RX/TX和GND引脚。
8. 将RPi连接到USB电源线并观察输出。
```console
Miniterm 1.0
[MT] ⏳ Waiting for /dev/ttyUSB0
[MT] ✅ Serial connected
[0] mingo version 0.5.0
[1] Booting on: Raspberry Pi 3
[2] Drivers loaded:
1. BCM PL011 UART
2. BCM GPIO
[3] Chars written: 117
[4] Echoing input now
```
8. 通过按下<kbd>ctrl-c</kbd>退出。
## 相比之前的变化diff
请检查[英文版本](README.md#diff-to-previous),这是最新的。

@ -54,8 +54,8 @@ The drivers themselves are stored in `src/bsp/device_driver`, and can be reused
first driver added in these tutorials is the `PL011Uart` driver: It implements the
`console::interface::*` traits and is from now on used as the main system console. The second driver
is the `GPIO` driver, which pinmuxes (that is, routing signals from inside the `SoC` to actual HW
pins) the RPi's PL011 UART accordingly. Note how the `GPIO` driver differentiates between **RPi3**
and **RPi4**. Their HW is different, so we have to account for it in SW.
pins) the RPi's PL011 UART accordingly. Note how the `GPIO` driver differentiates between **RPi 3**
and **RPi 4**. Their HW is different, so we have to account for it in SW.
The `BSP`s now also contain a memory map in `src/bsp/raspberrypi/memory.rs`. It provides the
Raspberry's `MMIO` addresses which are used by the `BSP` to instantiate the respective device
@ -64,18 +64,18 @@ drivers, so that the driver code knows where to find the device's registers in m
## Boot it from SD card
Since we have real `UART` output now, we can run the code on the real hardware. Building is
differentiated between the **RPi 3** and the **RPi4** due to before mentioned differences in the
differentiated between the **RPi 3** and the **RPi 4** due to before mentioned differences in the
`GPIO` driver. By default, all `Makefile` targets will build for the **RPi 3**. In order to build
for the the **RPi4**, prepend `BSP=rpi4` to each target. For example:
for the the **RPi 4**, prepend `BSP=rpi4` to each target. For example:
```console
$ BSP=rpi4 make
$ BSP=rpi4 make doc
```
Unfortunately, QEMU does not yet support the **RPi4**, so `BSP=rpi4 make qemu` won't work.
Unfortunately, QEMU does not yet support the **RPi 4**, so `BSP=rpi4 make qemu` won't work.
**Some steps for preparing the SD card differ between RPi3 and RPi4, so be careful in the
**Some steps for preparing the SD card differ between RPi 3 and RPi 4, so be careful in the
following.**
### Common for both
@ -87,7 +87,7 @@ following.**
arm_64bit=1
init_uart_clock=48000000
```
### Pi 3
### RPi 3
3. Copy the following files from the [Raspberry Pi firmware repo](https://github.com/raspberrypi/firmware/tree/master/boot) onto the SD card:
- [bootcode.bin](https://github.com/raspberrypi/firmware/raw/master/boot/bootcode.bin)
@ -95,7 +95,7 @@ init_uart_clock=48000000
- [start.elf](https://github.com/raspberrypi/firmware/raw/master/boot/start.elf)
4. Run `make`.
### Pi 4
### RPi 4
3. Copy the following files from the [Raspberry Pi firmware repo](https://github.com/raspberrypi/firmware/tree/master/boot) onto the SD card:
- [fixup4.dat](https://github.com/raspberrypi/firmware/raw/master/boot/fixup4.dat)
@ -104,7 +104,7 @@ init_uart_clock=48000000
4. Run `BSP=rpi4 make`.
_**Note**: Should it not work on your RPi4, try renaming `start4.elf` to `start.elf` (without the 4)
_**Note**: Should it not work on your RPi 4, try renaming `start4.elf` to `start.elf` (without the 4)
on the SD card._
### Common again

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