在 ArceOS 里增加 shell 命令的支持以便于进行驱动相关寄存器的调试

[limingth]

增加了 两条新命令， ldr 和 str ，模拟 ARM 汇编可以读写内存操作，用法如下

ldr ffff0000400fe000
读取内存地址 0xffff0000400fe000

str ffff0000400fe000 12345678
写入内存地址 ffff0000400fe000，值为 0x12345678

注意：地址和值，命令行里都无需加上 0x，因为字符串进行转换，默认是用了 radix: 16

加入 ldr 和 str 命令支持的代码已经push到我的fork库：https://github.com/limingth/arceos/

在 qemu 模拟器里的执行记录如下：

Available commands:
  cat
  cd
  echo
  exit
  help
  ls
  mkdir
  pwd
  rm
  uname
  ldr
  str
arceos:/$ ldr
ldr
try: ldr ffff0000400fe000 / ldr ffff000040080000 ffff000040080008
arceos:/$ str
str
try: str ffff0000400fe000 12345678
arceos:/$  ldr ffff0000400fe000
ldr
addr = ffff0000400fe000
Parsed address: 0xffff0000400fe000
Value at address ffff0000400fe000: 0xFFFF000040123000
arceos:/$  str ffff0000400fe000 12345678
str
First element: ffff0000400fe000
Second element: 12345678
addr = ffff0000400fe000
val = 12345678
Parsed address: 0xffff0000400fe000
Parsed value: 0x12345678
Write value at address ffff0000400fe000: 0x12345678
arceos:/$ ldr ffff0000400fe000
ldr
addr = ffff0000400fe000
Parsed address: 0xffff0000400fe000
Value at address ffff0000400fe000: 0x12345678
arceos:/$ 
arceos:/$ str ffff0000400fe000 11223344
str
First element: ffff0000400fe000
Second element: 11223344
addr = ffff0000400fe000
val = 11223344
Parsed address: 0xffff0000400fe000
Parsed value: 0x11223344
Write value at address ffff0000400fe000: 0x11223344
arceos:/$ ldr ffff0000400fe000
ldr
addr = ffff0000400fe000
Parsed address: 0xffff0000400fe000
Value at address ffff0000400fe000: 0x11223344
arceos:/$ ldr ffff0000400fe000
ldr
addr = ffff0000400fe000
Parsed address: 0xffff0000400fe000
Value at address ffff0000400fe000: 0x11223344
arceos:/$ ldr ffff0000400fe000
ldr
addr = ffff0000400fe000
Parsed address: 0xffff0000400fe000
Value at address ffff0000400fe000: 0x11223344
arceos:/$ str ffff0000400fe000 11226677
str
First element: ffff0000400fe000
Second element: 11226677
addr = ffff0000400fe000
val = 11226677
Parsed address: 0xffff0000400fe000
Parsed value: 0x11226677
Write value at address ffff0000400fe000: 0x11226677
arceos:/$ ldr ffff0000400fe000
ldr
addr = ffff0000400fe000
Parsed address: 0xffff0000400fe000
Value at address ffff0000400fe000: 0x11226677
arceos:/$ 

[limingth]

参考 arceos/platforms/aarch64-raspi4.toml 中关于 uart 寄存器地址的定义

# UART Address
uart-paddr = "0xFE20_1000"
uart-irq = "0x79"

对 0xffff0000fe201000 这个地址进行了写入实验，在 qemu-raspi4 模拟器里初步实验成功，
可以写入 0x67('g'), 0x68('h'), 0x69('i'), 0x6a('j'), 0x6b('k') ，并可以看到 qemu 将这些字符进行了输出。

以下是实验过程的输出记录：

arceos:/$ ldr ffff0000fe201000
ldr
addr = ffff0000fe201000
Parsed address: 0xffff0000fe201000
Value at address ffff0000fe201000: 0x66
arceos:/$ str ffff0000fe201000 67
str
First element: ffff0000fe201000
Second element: 67
addr = ffff0000fe201000
val = 67
Parsed address: 0xffff0000fe201000
Parsed value: 0x67
gWrite value at address ffff0000fe201000: 0x67
arceos:/$ str ffff0000fe201000 68
str
First element: ffff0000fe201000
Second element: 68
addr = ffff0000fe201000
val = 68
Parsed address: 0xffff0000fe201000
Parsed value: 0x68
hWrite value at address ffff0000fe201000: 0x68
arceos:/$ str ffff0000fe201000 69
str
First element: ffff0000fe201000
Second element: 69
addr = ffff0000fe201000
val = 69
Parsed address: 0xffff0000fe201000
Parsed value: 0x69
iWrite value at address ffff0000fe201000: 0x69
arceos:/$ str ffff0000fe201000 6a
str
First element: ffff0000fe201000
Second element: 6a
addr = ffff0000fe201000
val = 6a
Parsed address: 0xffff0000fe201000
Parsed value: 0x6A
jWrite value at address ffff0000fe201000: 0x6A
arceos:/$ str ffff0000fe201000 6b
str
First element: ffff0000fe201000
Second element: 6b
addr = ffff0000fe201000
val = 6b
Parsed address: 0xffff0000fe201000
Parsed value: 0x6B
kWrite value at address ffff0000fe201000: 0x6B
arceos:/$ 

上述输出中的最后一个 kWrite value at address ffff0000fe201000: 0x6B，最前面的 k 就是 0x6B 对应的字符，以上也可以类推。

[limingth]

同上，参考 arceos/platforms/aarch64-qemu-virt.toml 中关于 uart 寄存器地址的定义

# UART Address
uart-paddr = "0x0900_0000"
uart-irq = "1"

在 aarch64-qemu-virt 上运行如下

$ make A=apps/fs/shell ARCH=aarch64 PLATFORM=aarch64-qemu-virt  LOG=info BLK=y FEATURES=driver-ramdisk run
    Building App: shell, Arch: aarch64, Platform: aarch64-qemu-virt, App type: rust
cargo build --target aarch64-unknown-none-softfloat --target-dir /Users/liming/Github/Tsinghua/arceos/target --release  --manifest-path apps/fs/shell/Cargo.toml --features "axstd/log-level-info axstd/driver-ramdisk"
    Finished release [optimized] target(s) in 0.16s
rust-objcopy --binary-architecture=aarch64 apps/fs/shell/shell_aarch64-qemu-virt.elf --strip-all -O binary apps/fs/shell/shell_aarch64-qemu-virt.bin
    Running on qemu...
qemu-system-aarch64 -m 128M -smp 1 -cpu cortex-a72 -machine virt -kernel apps/fs/shell/shell_aarch64-qemu-virt.bin -device virtio-blk-device,drive=disk0 -drive id=disk0,if=none,format=raw,file=disk.img -nographic

       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-qemu-virt
target = aarch64-unknown-none-softfloat
smp = 1
build_mode = release
log_level = info

[  0.002754 0 axruntime:126] Logging is enabled.
[  0.003772 0 axruntime:127] Primary CPU 0 started, dtb = 0x44000000.
[  0.004120 0 axruntime:129] Found physcial memory regions:
[  0.004490 0 axruntime:131]   [PA:0x40080000, PA:0x400ae000) .text (READ | EXECUTE | RESERVED)
[  0.004938 0 axruntime:131]   [PA:0x400ae000, PA:0x400ba000) .rodata (READ | RESERVED)
[  0.005142 0 axruntime:131]   [PA:0x400ba000, PA:0x400be000) .data .tdata .tbss .percpu (READ | WRITE | RESERVED)
[  0.005320 0 axruntime:131]   [PA:0x400be000, PA:0x400fe000) boot stack (READ | WRITE | RESERVED)
[  0.005472 0 axruntime:131]   [PA:0x400fe000, PA:0x40123000) .bss (READ | WRITE | RESERVED)
[  0.005656 0 axruntime:131]   [PA:0x40123000, PA:0x48000000) free memory (READ | WRITE | FREE)
[  0.005898 0 axruntime:131]   [PA:0x9000000, PA:0x9001000) mmio (READ | WRITE | DEVICE | RESERVED)
[  0.006090 0 axruntime:131]   [PA:0x8000000, PA:0x8020000) mmio (READ | WRITE | DEVICE | RESERVED)
[  0.006242 0 axruntime:131]   [PA:0xa000000, PA:0xa004000) mmio (READ | WRITE | DEVICE | RESERVED)
[  0.006392 0 axruntime:131]   [PA:0x10000000, PA:0x3eff0000) mmio (READ | WRITE | DEVICE | RESERVED)
[  0.006546 0 axruntime:131]   [PA:0x4010000000, PA:0x4020000000) mmio (READ | WRITE | DEVICE | RESERVED)
[  0.006790 0 axruntime:207] Initialize global memory allocator...
[  0.006992 0 axruntime:208]   use TLSF allocator.
[  0.008884 0 axruntime:145] Initialize kernel page table...
[  0.010892 0 axruntime:149] Initialize platform devices...
[  0.011152 0 axdriver:152] Initialize device drivers...
[  0.011330 0 axdriver:153]   device model: static
[  0.025990 0 axdriver:124] registered a new Block device: "ramdisk"
[  0.026536 0 axfs:41] Initialize filesystems...
[  0.026708 0 axfs:44]   use block device 0: "ramdisk"
[  0.027356 0 fatfs::boot_sector:615] Invalid FAT type
[  0.041484 0 fatfs::dir:140] Is a directory
[  0.043818 0 fatfs::dir:140] Is a directory
[  0.047268 0 fatfs::dir:140] Is a directory
[  0.048584 0 fatfs::dir:140] Is a directory
[  0.049108 0 axruntime:185] Primary CPU 0 init OK.
Available commands:
  cat
  cd
  echo
  exit
  help
  ls
  mkdir
  pwd
  rm
  uname
  ldr
  str
arceos:/$ str ffff000009000000 6b
str
First element: ffff000009000000
Second element: 6b
addr = ffff000009000000
val = 6b
Parsed address: 0xffff000009000000
Parsed value: 0x6B
kWrite value at address ffff000009000000: 0x6B
arceos:/$ str ffff000009000000 6c
str
First element: ffff000009000000
Second element: 6c
addr = ffff000009000000
val = 6c
Parsed address: 0xffff000009000000
Parsed value: 0x6C
lWrite value at address ffff000009000000: 0x6C
arceos:/$