@ -28,6 +28,10 @@
- [给定应用 ](#lab4_challenge2_app )
- [实验内容 ](#lab4_challenge2_content )
- [实验指导 ](#lab4_challenge2_guide )
- [6.7 lab4_challenge3 简易Shell（ ： ） ](#lab4_challenge3_shell )
- [给定应用 ](#lab4_challenge3_app )
- [实验内容 ](#lab4_challenge3_content )
- [实验指导 ](#lab4_challenge3_guide )
< a name = "fundamental" > < / a >
@ -2348,7 +2352,7 @@ $ git commit -a -m "my work on lab4_3 is done."
- 本实验的具体要求为：
- 通过修改PKE内核和系统调用， ，以及一个调用参数数组 作为参数。exec函数在执行成功时不会返回，
- 通过修改PKE内核和系统调用， ， ，
< a name = "lab4_challenge2_guide" > < / a >
@ -2359,3 +2363,346 @@ $ git commit -a -m "my work on lab4_3 is done."
**注意： ， ， ， ， （ ） ， ，
**另外，后续的基础实验代码并不依赖挑战实验，所以读者可自行决定是否将自己的工作提交到本地代码仓库中（当然，提交到本地仓库是个好习惯，至少能保存自己的“作品”）。**
< a name = "lab4_challenge3_shell" > < / a >
## 6.7 lab4_challenge3 简易Shell（ ： ★ ★ ★ ★ ★ ）
< a name = "lab4_challenge3_app" > < / a >
#### 给定应用
- user/app_shell.c
```c
/*
* This app starts a very simple shell and executes some simple commands.
* The commands are stored in the hostfs_root/shellrc
* The shell loads the file and executes the command line by line.
*/
#include "user_lib.h"
#include "string.h"
#include "util/types.h"
int main(int argc, char *argv[]) {
printu("\n======== Shell Start ========\n\n");
int fd;
int MAXBUF = 1024;
char buf[MAXBUF];
char *token;
char delim[3] = " \n";
fd = open("/shellrc", O_RDONLY);
read_u(fd, buf, MAXBUF);
close(fd);
char *command = naive_malloc();
char *para = naive_malloc();
int start = 0;
while (1)
{
if(!start) {
token = strtok(buf, delim);
start = 1;
}
else
token = strtok(NULL, delim);
strcpy(command, token);
token = strtok(NULL, delim);
strcpy(para, token);
if(strcmp(command, "END") == 0 & & strcmp(para, "END") == 0)
break;
printu("Next command: %s %s\n\n", command, para);
printu("==========Command Start============\n\n");
int pid = fork();
if(pid == 0) {
int ret = exec(command, para);
if (ret == -1)
printu("exec failed!\n");
}
else
{
wait(pid);
printu("==========Command End============\n\n");
}
}
exit(0);
return 0;
}
```
该应用程序从位于hostfs_root下的shellrc文件中读取若干条命令， ， ， ，
给出的shellrc文件如下：
```
/bin/app_mkdir /RAMDISK0/sub_dir
/bin/app_touch /RAMDISK0/sub_dir/ramfile1
/bin/app_touch /RAMDISK0/sub_dir/ramfile2
/bin/app_echo /RAMDISK0/sub_dir/ramfile1
/bin/app_cat /RAMDISK0/sub_dir/ramfile1
/bin/app_ls /RAMDISK0/sub_dir
/bin/app_ls /RAMDISK0
END END
```
可以看到， ， ， ， ， ， （ ， ， ： ）
同样是为了简单起见，
shellrc中的其余命令实现均位于user目录下， ，
shell程序将会依次执行上述命令， ， ：
```
$ spike obj/riscv-pke /bin/app_shell
In m_start, hartid:0
HTIF is available!
(Emulated) memory size: 2048 MB
Enter supervisor mode...
PKE kernel start 0x0000000080000000, PKE kernel end: 0x0000000080011000, PKE kernel size: 0x0000000000011000 .
free physical memory address: [0x0000000080011000, 0x0000000087ffffff]
kernel memory manager is initializing ...
KERN_BASE 0x0000000080000000
physical address of _etext is: 0x0000000080009000
kernel page table is on
RAMDISK0: base address of RAMDISK0 is: 0x0000000087f35000
RFS: format RAMDISK0 done!
Switch to user mode...
in alloc_proc. user frame 0x0000000087f29000, user stack 0x000000007ffff000, user kstack 0x0000000087f28000
FS: created a file management struct for a process.
in alloc_proc. build proc_file_management successfully.
User application is loading.
Application: /bin/app_shell
CODE_SEGMENT added at mapped info offset:4
DATA_SEGMENT added at mapped info offset:5
Application program entry point (virtual address): 0x00000000000100b0
going to insert process 0 to ready queue.
going to schedule process 0 to run.
======== Shell Start ========
Next command: /bin/app_mkdir /RAMDISK0/sub_dir
==========Command Start============
User call fork.
will fork a child from parent 0.
in alloc_proc. user frame 0x0000000087f0e000, user stack 0x000000007ffff000, user kstack 0x0000000087f0c000
FS: created a file management struct for a process.
in alloc_proc. build proc_file_management successfully.
do_fork map code segment at pa:0000000087f13000 of parent to child at va:0000000000010000.
going to insert process 1 to ready queue.
going to schedule process 1 to run.
Application: /bin/app_mkdir
CODE_SEGMENT added at mapped info offset:4
Application program entry point (virtual address): 0x0000000000010078
======== mkdir command ========
mkdir: /RAMDISK0/sub_dir
User exit with code:0.
going to insert process 0 to ready queue.
going to schedule process 0 to run.
==========Command End============
Next command: /bin/app_touch /RAMDISK0/sub_dir/ramfile1
==========Command Start============
User call fork.
will fork a child from parent 0.
in alloc_proc. user frame 0x0000000087ef3000, user stack 0x000000007ffff000, user kstack 0x0000000087ef2000
FS: created a file management struct for a process.
in alloc_proc. build proc_file_management successfully.
do_fork map code segment at pa:0000000087f13000 of parent to child at va:0000000000010000.
going to insert process 2 to ready queue.
going to schedule process 2 to run.
Application: /bin/app_touch
CODE_SEGMENT added at mapped info offset:4
Application program entry point (virtual address): 0x0000000000010078
======== touch command ========
touch: /RAMDISK0/sub_dir/ramfile1
file descriptor fd: 0
User exit with code:0.
going to insert process 0 to ready queue.
going to schedule process 0 to run.
==========Command End============
Next command: /bin/app_touch /RAMDISK0/sub_dir/ramfile2
==========Command Start============
User call fork.
will fork a child from parent 0.
in alloc_proc. user frame 0x0000000087ee8000, user stack 0x000000007ffff000, user kstack 0x0000000087ee6000
FS: created a file management struct for a process.
in alloc_proc. build proc_file_management successfully.
do_fork map code segment at pa:0000000087f13000 of parent to child at va:0000000000010000.
going to insert process 3 to ready queue.
going to schedule process 3 to run.
Application: /bin/app_touch
CODE_SEGMENT added at mapped info offset:4
Application program entry point (virtual address): 0x0000000000010078
======== touch command ========
touch: /RAMDISK0/sub_dir/ramfile2
file descriptor fd: 0
User exit with code:0.
going to insert process 0 to ready queue.
going to schedule process 0 to run.
==========Command End============
Next command: /bin/app_echo /RAMDISK0/sub_dir/ramfile1
==========Command Start============
User call fork.
will fork a child from parent 0.
in alloc_proc. user frame 0x0000000087ed1000, user stack 0x000000007ffff000, user kstack 0x0000000087ecf000
FS: created a file management struct for a process.
in alloc_proc. build proc_file_management successfully.
do_fork map code segment at pa:0000000087f13000 of parent to child at va:0000000000010000.
going to insert process 4 to ready queue.
going to schedule process 4 to run.
Application: /bin/app_echo
CODE_SEGMENT added at mapped info offset:4
DATA_SEGMENT added at mapped info offset:5
Application program entry point (virtual address): 0x00000000000100b0
======== echo command ========
echo: /RAMDISK0/sub_dir/ramfile1
file descriptor fd: 0
write content:
hello world
User exit with code:0.
going to insert process 0 to ready queue.
going to schedule process 0 to run.
==========Command End============
Next command: /bin/app_cat /RAMDISK0/sub_dir/ramfile1
==========Command Start============
User call fork.
will fork a child from parent 0.
in alloc_proc. user frame 0x0000000087eba000, user stack 0x000000007ffff000, user kstack 0x0000000087eb8000
FS: created a file management struct for a process.
in alloc_proc. build proc_file_management successfully.
do_fork map code segment at pa:0000000087f13000 of parent to child at va:0000000000010000.
going to insert process 5 to ready queue.
going to schedule process 5 to run.
Application: /bin/app_cat
CODE_SEGMENT added at mapped info offset:4
Application program entry point (virtual address): 0x0000000000010078
======== cat command ========
cat: /RAMDISK0/sub_dir/ramfile1
file descriptor fd: 0
read content:
hello world
User exit with code:0.
going to insert process 0 to ready queue.
going to schedule process 0 to run.
==========Command End============
Next command: /bin/app_ls /RAMDISK0/sub_dir
==========Command Start============
User call fork.
will fork a child from parent 0.
in alloc_proc. user frame 0x0000000087ea2000, user stack 0x000000007ffff000, user kstack 0x0000000087ea0000
FS: created a file management struct for a process.
in alloc_proc. build proc_file_management successfully.
do_fork map code segment at pa:0000000087f13000 of parent to child at va:0000000000010000.
going to insert process 6 to ready queue.
going to schedule process 6 to run.
Application: /bin/app_ls
CODE_SEGMENT added at mapped info offset:4
DATA_SEGMENT added at mapped info offset:5
Application program entry point (virtual address): 0x00000000000100b0
---------- ls command -----------
ls "/RAMDISK0/sub_dir":
[name] [inode_num]
ramfile1 2
ramfile2 3
------------------------------
User exit with code:0.
going to insert process 0 to ready queue.
going to schedule process 0 to run.
==========Command End============
Next command: /bin/app_ls /RAMDISK0
==========Command Start============
User call fork.
will fork a child from parent 0.
in alloc_proc. user frame 0x0000000087e8b000, user stack 0x000000007ffff000, user kstack 0x0000000087f14000
FS: created a file management struct for a process.
in alloc_proc. build proc_file_management successfully.
do_fork map code segment at pa:0000000087f13000 of parent to child at va:0000000000010000.
going to insert process 7 to ready queue.
going to schedule process 7 to run.
Application: /bin/app_ls
CODE_SEGMENT added at mapped info offset:4
DATA_SEGMENT added at mapped info offset:5
Application program entry point (virtual address): 0x00000000000100b0
---------- ls command -----------
ls "/RAMDISK0":
[name] [inode_num]
sub_dir 1
------------------------------
User exit with code:0.
going to insert process 0 to ready queue.
going to schedule process 0 to run.
==========Command End============
User exit with code:0.
no more ready processes, system shutdown now.
System is shutting down with exit code 0.
```
< a name = "lab4_challenge3_content" > < / a >
#### 实验内容
本实验为挑战实验， ：
- 先提交lab4_3_hardlink的答案， ） ：
```bash
//切换到lab4_challenge3_shell
$ git checkout lab4_challenge3_shell
//继承lab4_3_hardlink以及之前的答案
$ git merge lab4_3_hardlink -m "continue to work on lab4_challenge3"
```
注意：**不同于基础实验，挑战实验的基础代码具有更大的不完整性，可能无法直接通过构造过程。** 同样，不同于基础实验，我们在代码中也并未专门地哪些地方的代码需要填写，哪些地方的代码无须填写。这样，我们留给读者更大的“想象空间”。
- 本实验的具体要求为：
- 通过修改PKE内核和系统调用， ， （ ， ， ， ， ）
- 此外， ， ， ，
< a name = "lab4_challenge3_guide" > < / a >
#### 实验指导
shell是Linux中的一个重要概念， ： ， ， ， （ ， ）
不考虑参数传递问题的话， ， ， ：
- main函数中的argc， ， （ ： ， ）
- 在lab1中我们初步了解了系统调用， ， ：
- 在exec替换完elf后， ，
- 注意地址对齐。读者可自行参阅RISC-V的相关资料，
**注意： ， ， ， ， ，
**另外，后续的基础实验代码并不依赖挑战实验，所以读者可自行决定是否将自己的工作提交到本地代码仓库中（当然，提交到本地仓库是个好习惯，至少能保存自己的“作品”）。**
liguo