树莓派启动sd卡kernel8.img实现加载arceos-raspi4.bin的全过程

[limingth]

1. 修改 bcm2xxx_pl011_uart.rs 的波特率为 115200

参考 https://github.com/chenlongos/rust-raspberrypi-OS-tutorials/tree/master/06_uart_chainloader

src/bsp/device_driver/bcm/bcm2xxx_pl011_uart.rs

        // Set new baud rate = 115200
        // (48_000_000 / 16) / 115200 = 26.0416667
        // INTEGER((0.0416667 * 64) + 0.5) = 3.16666688
        self.registers.IBRD.write(IBRD::BAUD_DIVINT.val(26));
        self.registers.FBRD.write(FBRD::BAUD_DIVFRAC.val(3));

$ BSP=rpi4 make
在 make 之前必须加上 BSP=rpi4

2. 修改 main.rs 最后的加载程序逻辑，改为从 src_addr 拷贝 100000 个字节到 0x80000，然后跳转过去执行

    let kernel_addr: *mut u8 = bsp::memory::board_default_load_addr() as *mut u8;

    // board_default_load_addr() is 0x8_0000
    let base = 0x8_0000;
    let src_addr: *const u8 = (base + 9152) as *const u8; // 9152 is size of original kernel8.img
    let size = 100000; // 100000 is enough for arceos-raspi4.bin
    unsafe {
        // Read the kernel byte by byte.
        for i in 0..size {
            core::ptr::write_volatile(kernel_addr.offset(i as isize), *src_addr.offset(i))
        }
    }

    println!("[ML] Loaded! Executing the payload now\n");
    console().flush();

    // Use black magic to create a function pointer.
    let kernel: fn() -> ! = unsafe { core::mem::transmute(kernel_addr) };

    // Jump to loaded kernel!
    kernel()

3. 修改编译 arceos 代码，生成树莓派4b上的 helloworld_aarch64-raspi4.bin 文件

$ make A=apps/helloworld ARCH=aarch64 PLATFORM=aarch64-raspi4  LOG=debug 
    Building App: helloworld, Arch: aarch64, Platform: aarch64-raspi4, App type: rust
cargo build --target aarch64-unknown-none-softfloat --target-dir /Users/liming/Github/Tsinghua/arceos/target --release  --manifest-path apps/helloworld/Cargo.toml --features "axstd/log-level-debug"
   Compiling syn v2.0.29
   Compiling axhal v0.1.0 (/Users/liming/Github/Tsinghua/arceos/modules/axhal)
   Compiling axio v0.1.0 (/Users/liming/Github/Tsinghua/arceos/crates/axio)
   Compiling crate_interface v0.1.1 (/Users/liming/Github/Tsinghua/arceos/crates/crate_interface)
   Compiling percpu_macros v0.1.0 (/Users/liming/Github/Tsinghua/arceos/crates/percpu_macros)
   Compiling kernel_guard v0.1.0 (/Users/liming/Github/Tsinghua/arceos/crates/kernel_guard)
   Compiling percpu v0.1.0 (/Users/liming/Github/Tsinghua/arceos/crates/percpu)
   Compiling spinlock v0.1.0 (/Users/liming/Github/Tsinghua/arceos/crates/spinlock)
   Compiling axlog v0.1.0 (/Users/liming/Github/Tsinghua/arceos/modules/axlog)
   Compiling axruntime v0.1.0 (/Users/liming/Github/Tsinghua/arceos/modules/axruntime)
   Compiling axfeat v0.1.0 (/Users/liming/Github/Tsinghua/arceos/api/axfeat)
   Compiling arceos_api v0.1.0 (/Users/liming/Github/Tsinghua/arceos/api/arceos_api)
   Compiling axstd v0.1.0 (/Users/liming/Github/Tsinghua/arceos/ulib/axstd)
   Compiling arceos-helloworld v0.1.0 (/Users/liming/Github/Tsinghua/arceos/apps/helloworld)
    Finished release [optimized] target(s) in 6.26s
rust-objcopy --binary-architecture=aarch64 apps/helloworld/helloworld_aarch64-raspi4.elf --strip-all -O binary apps/helloworld/helloworld_aarch64-raspi4.bin

4. 把 kernel8.img 和 helloworld_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/helloworld/helloworld_aarch64-raspi4.bin > kernel8.img
$ ls -l kernel8.img 
-rw-r--r--  1 liming  staff  259072  9 13 17:52 kernel8.img

5. 把新生成的 kernel8.img 拷贝到 sd 卡上，重新启动树莓派板子，可以看到上电后输出 miniload 并进入到 arceos helloworld 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

[  0.108847 0 axruntime:126] Logging is enabled.
[  0.114576 0 axruntime:127] Primary CPU 0 started, dtb = 0x0.
[  0.121522 0 axruntime:129] Found physcial memory regions:
[  0.128209 0 axruntime:131]   [PA:0x80000, PA:0x86000) .text (READ | EXECUTE | RESERVED)
[  0.137498 0 axruntime:131]   [PA:0x86000, PA:0x88000) .rodata (READ | RESERVED)
[  0.146093 0 axruntime:131]   [PA:0x88000, PA:0x8c000) .data .tdata .tbss .percpu (READ | WRITE | RESERVED)
[  0.157033 0 axruntime:131]   [PA:0x8c000, PA:0xcc000) boot stack (READ | WRITE | RESERVED)
[  0.166583 0 axruntime:131]   [PA:0xcc000, PA:0xcd000) .bss (READ | WRITE | RESERVED)
[  0.175613 0 axruntime:131]   [PA:0x0, PA:0x1000) spintable (READ | WRITE | RESERVED)
[  0.184642 0 axruntime:131]   [PA:0xcd000, PA:0xfc000000) free memory (READ | WRITE | FREE)
[  0.194193 0 axruntime:131]   [PA:0xfe201000, PA:0xfe202000) mmio (READ | WRITE | DEVICE | RESERVED)
[  0.204525 0 axruntime:131]   [PA:0xff841000, PA:0xff849000) mmio (READ | WRITE | DEVICE | RESERVED)
[  0.214857 0 axruntime:149] Initialize platform devices...
[  0.221542 0 axruntime:185] Primary CPU 0 init OK.
Hello, world! 
[  9.556116 0 axruntime:198] main task exited: exit_code=0
[  9.560792 0 axhal::platform::aarch64_raspi::misc:21] Shutting down...