实验五：树莓派启动 ArceOS,执行shell命令

在ArceOS目录下，输入：
```
make A=apps/cli ARCH=aarch64 PLATFORM=aarch64-raspi4 LOG=debug
```
编译出ArceOS在raspi4 上的镜像。
生成kernel8.img文件
```
BSP=rpi4 make
```
把 kernel8.img 和 cli_aarch64-raspi4.bin 通过 cat 命令拼接到一个 bin 文件中，仍然取名为 kernel8.img：
```
cat ../rust-raspberrypi-OS-tutorials/06_uart_chainloader/kernel8.img apps/cli/cli_aarch64-raspi4.bin > kernel8.img
```

若已有树莓派开发板则进行以下操作：

把新生成的 kernel8.img 拷贝到 sd 卡上。
将树莓派与PC相连，打开连接软件。

启动树莓派板子，可以看到上电后输出 miniload 并进入到 shell 命令里：

       d8888                            .d88888b.   .d8888b.
      d88888                           d88P" "Y88b d88P  Y88b
     d88P888                           888     888 Y88b.
    d88P 888 888d888  .d8888b  .d88b.  888     888  "Y888b.
   d88P  888 888P"   d88P"    d8P  Y8b 888     888     "Y88b.
  d88P   888 888     888      88888888 888     888       "888
 d8888888888 888     Y88b.    Y8b.     Y88b. .d88P Y88b  d88P
d88P     888 888      "Y8888P  "Y8888   "Y88888P"   "Y8888P"

arch = aarch64
platform = aarch64-raspi4
target = aarch64-unknown-none-softfloat
smp = 1
build_mode = release
log_level = debug

[  0.108866 0 axruntime:126] Logging is enabled.
[  0.114596 0 axruntime:127] Primary CPU 0 started, dtb = 0x0.
[  0.121542 0 axruntime:129] Found physcial memory regions:
[  0.128229 0 axruntime:131]   [PA:0x80000, PA:0x8a000) .text (READ | EXECUTE | RESERVED)
[  0.137517 0 axruntime:131]   [PA:0x8a000, PA:0x8d000) .rodata (READ | RESERVED)
[  0.146113 0 axruntime:131]   [PA:0x8d000, PA:0x91000) .data .tdata .tbss .percpu (READ | WRITE | RESERVED)
[  0.157053 0 axruntime:131]   [PA:0x91000, PA:0xd1000) boot stack (READ | WRITE | RESERVED)
[  0.166603 0 axruntime:131]   [PA:0xd1000, PA:0xd2000) .bss (READ | WRITE | RESERVED)
[  0.175633 0 axruntime:131]   [PA:0x0, PA:0x1000) spintable (READ | WRITE | RESERVED)
[  0.184662 0 axruntime:131]   [PA:0xd2000, PA:0xfc000000) free memory (READ | WRITE | FREE)
[  0.194213 0 axruntime:131]   [PA:0xfe201000, PA:0xfe202000) mmio (READ | WRITE | DEVICE | RESERVED)
[  0.204545 0 axruntime:131]   [PA:0xff841000, PA:0xff849000) mmio (READ | WRITE | DEVICE | RESERVED)
[  0.214877 0 axruntime:149] Initialize platform devices...
[  0.221562 0 axruntime:185] Primary CPU 0 init OK.
Available commands:
  exit
  help
  uname
  ldr
  str
arceos#

尝试修改ldr命令相关代码（位置arceos/apps/cli/src/cmd.rs）：
- 目前的ldr只能以8个字节为间隔来读取地址的值，要求改为以4个字节为间隔来读取地址的值（地址都是以16进制表示的），例如：
```
arceos# ldr ffff0000fe201000
ldr
Value at address 0xffff0000fe201000: 0x31

arceos# ldr ffff0000fe201004   //修改前如果输入ldr ffff0000fe201004 会直接崩溃
ldr
Value at address 0xffff0000fe201000: 0x0
```
- 目前的ldr只能将完整的地址输入进去才能输出，要求改为输入一个地址加一个数字，可以直接输出一排相邻地址的值（起始的值为输入的地址的值，输出的值的个数取决于输入的数字，不输入默认为1），例如：
```
arceos# ldr ffff0000fe201000 5 //修改前只能输入ldr ffff0000fe201000 ffff0000fe201008
ldr
Value at address 0xffff0000fe201000: 0x31
Value at address 0xffff0000fe201004: 0x0
Value at address 0xffff0000fe201008: 0x0
Value at address 0xffff0000fe20100c: 0x0
Value at address 0xffff0000fe201010: 0x0
```
尝试修改str命令相关代码

目前的str只能以8个字节为间隔来写入地址的值，要求改为以4个字节为间隔来写入地址的值（地址都是以16进制表示的），例如：
```
arceos# str ffff0000fe201000 123

arceos# str ffff0000fe201004 123  //修改前如果输入ldr ffff0000fe201004 会直接崩溃
```
尝试输出字母A：

尝试向ffff0000fe201000中写入41，使其输出字母A：
```
arceos# str ffff0000fe201000 41
Aarceos# 
```
可以看到输出了一个字母A。（如果没有输出A，可能原因是提供的str代码执行后会打印出很多东西，导致A的结果被顶掉了，所以可以把一些打印语句删除再进行尝试）

若没有开发板则在qemu模拟器中运行：

在qemu中运行kernel8.img：

./qemu-system-aarch64 -m 2G -smp 4 -cpu cortex-a72 -machine raspi4b2g -nographic -kernel arceos/kernel8.img

可以看到输出：

       d8888                            .d88888b.   .d8888b.
      d88888                           d88P" "Y88b d88P  Y88b
     d88P888                           888     888 Y88b.
    d88P 888 888d888  .d8888b  .d88b.  888     888  "Y888b.
   d88P  888 888P"   d88P"    d8P  Y8b 888     888     "Y88b.
  d88P   888 888     888      88888888 888     888       "888
 d8888888888 888     Y88b.    Y8b.     Y88b. .d88P Y88b  d88P
d88P     888 888      "Y8888P  "Y8888   "Y88888P"   "Y8888P"

arch = aarch64
platform = aarch64-raspi4
target = aarch64-unknown-none-softfloat
smp = 1
build_mode = release
log_level = debug

[  0.108866 0 axruntime:126] Logging is enabled.
[  0.114596 0 axruntime:127] Primary CPU 0 started, dtb = 0x0.
[  0.121542 0 axruntime:129] Found physcial memory regions:
[  0.128229 0 axruntime:131]   [PA:0x80000, PA:0x8a000) .text (READ | EXECUTE | RESERVED)
[  0.137517 0 axruntime:131]   [PA:0x8a000, PA:0x8d000) .rodata (READ | RESERVED)
[  0.146113 0 axruntime:131]   [PA:0x8d000, PA:0x91000) .data .tdata .tbss .percpu (READ | WRITE | RESERVED)
[  0.157053 0 axruntime:131]   [PA:0x91000, PA:0xd1000) boot stack (READ | WRITE | RESERVED)
[  0.166603 0 axruntime:131]   [PA:0xd1000, PA:0xd2000) .bss (READ | WRITE | RESERVED)
[  0.175633 0 axruntime:131]   [PA:0x0, PA:0x1000) spintable (READ | WRITE | RESERVED)
[  0.184662 0 axruntime:131]   [PA:0xd2000, PA:0xfc000000) free memory (READ | WRITE | FREE)
[  0.194213 0 axruntime:131]   [PA:0xfe201000, PA:0xfe202000) mmio (READ | WRITE | DEVICE | RESERVED)
[  0.204545 0 axruntime:131]   [PA:0xff841000, PA:0xff849000) mmio (READ | WRITE | DEVICE | RESERVED)
[  0.214877 0 axruntime:149] Initialize platform devices...
[  0.221562 0 axruntime:185] Primary CPU 0 init OK.
Available commands:
  exit
  help
  uname
  ldr
  str
arceos#

同上面的第7步
同上面的第8步
同上面的第9步

至此，实验五结束，最终提交实验过程记录（包含出现的各类问题及解决办法）以及关于ArceOS成功运行，并且执行ldr一次输出20个值的结果（以ffff0000fe201000为起始地址），最后再成功输出字母A的结果。

raspi4-with-arceos-doc

实验五：树莓派启动 ArceOS,执行shell命令