first commit

.gitignore

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+# cargo config
+os/Cargo.lock
+user/Cargo.lock
+os/src/linker.ld
+os/new_cmd
+
+# IDE config
+.idea/
+.vscode/
+
+# kernel build
+os/target/
+
+# user programs build
+user/riscv64/
+user/target/
+
+# Gathering place of images
+easy-fs-fuse/
+
+# a copy of user programs debug build in "user/target/*"(for gdb)
+os/user/
+
+#gdb script
+os/gdb_script
+
+# developing, should be invisible in main branch
+os/src/fs/fatfs/*
+
+# unsorted
+os/output.txt
+os/logs/
+os/src/link_app.S
+os/last-*
+tools/
+user/.ccls-cache/
+
+# Doc .org & .tex
+Doc/**/*.org
+Doc/**/*.tex
+Doc/**/*.jpg
+Doc/**/*.png

Doc/2K1000上板过程问题.md

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+# 2K1000上板过程问题
+
+## UART地址设置
+
+UART0寄存器（映射）基址：0x8000_0000_1fe2_0000
+
+出处：U-Boot源码解析（龙芯版）章节5.3.2。指向U-Boot源码：u-boot-2022.04-2k1000
+```asm
+/arch/loongarch/mach-loongson/ls2k100/lowlevel_init.S:394
+
+#define UART_REF_CLK	125000000
+#define UART_DIV_HI	 (((UART_REF_CLK + (115200*8)) / (115200*16)) >> 8)
+#define UART_DIV_LO	(((UART_REF_CLK + (115200*8)) / (115200*16)) & 0xff)
+ENTRY(init_serial)
+	or  a4, ra, zero      /*返回地址写入a4*/
+
+	li.d	a0, CONSOLE_BASE_ADDR
+    /*UART0寄存器（映射）基址：0x8000_0000_1fe2_0000*/
+    /*/include/configs/loongson_2k1000.h*/
+    /*/arch/loongarch/mach-loongson/include/mach/ls2k1000/ls2k1000.h*/
+```
+
+## NAND_BASE与DMA_ADDR
+
+NAND_BASE: usize = 0x1fe2_6000 | HIGH_BASE_EIGHT;
+DMA_ADDR: usize = 0x1fe0_0c00 | HIGH_BASE_EIGHT;
+
+出处：U-Boot源码解析（龙芯版）章节9.5.1。
+
+通过搜索NAND找到的，在U-Boot源码中也得到了验证，观察其中的reg项可以找到地址。
+
+在2K500：
+```
+arch/loongarch/dts/ls2k500.dtsi
+
+577行：
+nand: nand-controller@1ff58000 {
+    compatible = "loongson,ls-nand";
+    reg = <0 0x1ff58000 0 0x4000>;
+    pinctrl-names = "default";
+    pinctrl-0 = <&nand_pins>;
+    dmas = <&dma0 0>;
+    dma-names = "nand-rw";
+    nand-cs-origin = <0>;
+    nand-ecc-algo = "bch";  // "bch", "none"
+    nand-ecc-strength = <4>;
+    status = "disabled";
+};
+
+342行：
+dma0: dma@1fe10c00 {
+    compatible = "loongson,ls2k500-dma";
+    reg = <0 0x1fe10c00 0 0x4>;
+    dma-cfg = <&dmacfg 0 LS_DMA_OWNER_NAND>; // arg[0]: channel id  arg[1]: dma owner
+    #dma-cells = <1>;
+    dma-channels = <1>;
+    dma-requests = <1>;
+};
+```
+在2K1000：
+```
+arch/loongarch/dts/ls2k1000.dtsi
+
+505行：
+nand: nand-controller@1fe26000 {
+    compatible = "loongson,ls-nand";
+    reg = <0 0x1fe26000 0 0x44>;
+    pinctrl-names = "default";
+    pinctrl-0 = <&pinmux_nand_nand>;
+    dmas = <&dma0 0>;
+    dma-names = "nand-rw";
+    nand-cs-origin = <2>;
+    nand-ecc-algo = "bch";  // "bch", "none"
+    nand-ecc-strength = <4>;
+    status = "disabled";
+};
+
+379行：
+dma0: dma@1fe00c00 {
+    compatible = "loongson,ls2k1000-dma";
+    reg = <0 0x1fe00c00 0 0x8>;
+    dma-cfg = <&dmacfg 0 LS_DMA_OWNER_NAND>; // arg[0]: channel id  arg[1]: dma owner
+    #dma-cells = <1>;
+    dma-channels = <1>;
+    dma-requests = <1>;
+};
+```

Doc/2k500QEMU可能遇到的问题.md

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+1. version `GLIBC_2.34‘ not found 报错
+
+检查版本：
+``` shell
+strings /lib/x86_64-linux-gnu/libc.so.6 |grep GLIBC_
+```
+显示结果，最高只到GLIBC_2.30，由于使用的系统为ubuntu20.04，已经升级到了系统版本的最高版本了。
+
+解决方案：添加一个高级版本系统的源，直接升级libc6。
+
+编辑源：在/etc/apt/sources.list文件添加一行：
+```
+deb http://th.archive.ubuntu.com/ubuntu jammy main
+```
+
+运行升级：
+``` shell
+sudo apt update
+sudo apt install libc6
+```
+
+参考：https://blog.csdn.net/huazhang_001/article/details/128828999
+
+2. /opt/cross-my/libexec/gcc/loongarch64-unknown-linux-gnu/12.2.0/cc1: error while loading shared libraries: libisl.so.23: cannot open shared object file: No such file or directory
+
+``` shell
+sudo apt-get install libisl-dev
+```
+
+参考：https://stackoverflow.com/questions/33734143/gcc-unable-to-find-shared-library-libisl-so
+
+3. make: ./la_fat: Command not found
+
+因为os/la_fat文件开头为#!/usr/bin/expect -f。需要安装expect：
+``` shell
+sudo apt-get install expect
+```
+4. error while loading shared libraries: libssl.so.3: cannot open shared object file: No such file or directory
+``` shell
+sudo apt-get install openssl
+```
+
+5. unknown feature
+
+注释掉：
+```rust
+// #![feature(btree_drain_filter)]
+// #![feature(drain_filter)]
+```
+
+`rustc` version is `rustc 1.73.0-nightly (32303b219 2023-07-29)`

Doc/2k500开发板可能遇到的问题.md

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+1. No module named'serial'
+```
+Error while finding module specification for 'serial.tools.list_ports' (ModuleNotFoundError: No module named'serial')`
+```
+```bash
+pip install pyserial
+```
+2.  Permission denied: '/dev/ttyUSB0'
+```bash
+sudo chmod -R 777 /dev/ttyUSB0
+```

Doc/dbg/LAQEMU调试.md

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+# LAQEMU调试
+
+## 环境准备
+
+### LA GDB安装
+
+参考：https://blog.csdn.net/greenmoss/article/details/127800221
+
+gdb 12.1版本已经支持LoongArch架构
+
+1. 下载安装包
+```bash
+wget http://ftp.gnu.org/gnu/gdb/gdb-12.1.tar.gz
+```
+若下载过慢，可以在windows系统下直接访问ftp链接通过浏览器下载，拷贝到Ubuntu中。
+
+2. 解压安装包
+```bash
+tar -zxvf gdb-12.1.tar.gz
+```
+
+3. 预编译
+```bash
+cd gdb-12.1    # 进入文件夹gdb-12.1
+mkdir build    # 建立文件夹build
+cd build 		# 进入文件夹build
+../configure --prefix=/usr --target=loongarch64-unknown-linux-gnu
+```
+
+4. 编译
+```bash
+make
+make install
+```
+上述两句均需执行，可能需要较长时间，请耐心等待。
+
+在`make install`时若出现权限不足的报错，尝试使用`sudo make install`。
+
+成功之后：
+```
+See any operating system documentation about shared libraries for
+more information, such as the ld(1) and ld.so(8) manual pages.
+----------------------------------------------------------------------
+ /usr/bin/mkdir -p '/usr/include'
+ /usr/bin/install -c -m 644 ../../libctf/../include/ctf.h ../../libctf/../include/ctf-api.h '/usr/include'
+ /usr/bin/mkdir -p '/usr/share/info'
+ /usr/bin/install -c -m 644 ../../libctf/doc/ctf-spec.info '/usr/share/info'
+make[3]: 离开目录“/home/loongson/gdb-12.1/build/libctf”
+make[2]: 离开目录“/home/loongson/gdb-12.1/build/libctf”
+make[1]: 对“install-target”无需做任何事。
+make[1]: 离开目录“/home/loongson/gdb-12.1/build”
+```
+
+5. 运行
+```bash
+cd /gdb
+./gdb
+```
+检查升级后的版本：
+```
+GNU gdb (GDB) 12.1
+Copyright (C) 2022 Free Software Foundation, Inc.
+License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
+This is free software: you are free to change and redistribute it.
+There is NO WARRANTY, to the extent permitted by law.
+Type "show copying" and "show warranty" for details.
+This GDB was configured as "loongarch64-unknown-linux-gnu".
+Type "show configuration" for configuration details.
+For bug reporting instructions, please see:
+<https://www.gnu.org/software/gdb/bugs/>.
+Find the GDB manual and other documentation resources online at:
+    <http://www.gnu.org/software/gdb/documentation/>.
+
+For help, type "help".
+Type "apropos word" to search for commands related to "word".
+```
+注意检查，第一行GDB版本为12.1，第七行GDB的config为`loongarch64-unknown-linux-gnu`。
+
+### VScode调试配置
+
+安装插件 C/C++ ，在工作区下面的 .vscode 目录下新建 launch.json 文件，并写入如下内容：
+
+```json
+{
+   "version": "0.2.0",
+   "configurations": [
+      {
+            "type": "cppdbg",
+            "request": "launch",
+            "name": "Attach to gdbserver",
+            "program": "${workspaceFolder}/os/target/loongarch64-unknown-linux-gnu/debug/os",
+            "miDebuggerServerAddress": "localhost:1234",
+            "miDebuggerPath": "path/to/gdb-12.1/build/gdb/gdb",
+            "cwd": "${workspaceRoot}/os",
+      }
+   ]
+}
+```
+
+注意修改`miDebuggerPath`中的`path/to`为自己电脑上的路径。
+
+## 开始调试
+
+在`os`目录下输入`make gdb`命令，回车，进入GDB连接等待。
+
+> 如果内核代码已被修改，通过`make new-gdb`命令，会先进行`build`，再进行`GDB`连接等待。
+
+在内核代码中打上断点，再点击VScode面板中的开始调试（快捷键为F5），之后可以看到内核继续运行，停在所打断点处。