cleanup

apps/system/sys_proc.c

@@ -68,7 +68,7 @@ static int app_read(int block_no, char* dst) {
 }
 
 static int app_spawn(struct proc_request *req) {
- int bin_ino = dir_lookup(0, "bin");
+ int bin_ino = dir_lookup(0, "bin/");
  if ((app_ino = dir_lookup(bin_ino, req->argv[0])) < 0) return -1;
 
  app_pid = grass->proc_alloc();

apps/system/sys_shell.c

@@ -26,43 +26,32 @@ void parse_request(char* buf, struct proc_request* req) {
 
 int main() {
  SUCCESS("Enter kernel process GPID_SHELL");
-
- char work_dir[] = "/home/yunhao";
- strcpy(grass->work_dir_name, "yunhao");
-
- int home_ino = dir_lookup(0, "home");
- grass->work_dir_ino = dir_lookup(home_ino, "yunhao");
- INFO("sys_shell: %s has ino=%d", work_dir, grass->work_dir_ino);
  CRITICAL("Welcome to egos-2000!");
 
- /* Wait for shell commands */
+ char buf[256] = "cd"; /* Enter the home directory first */
  while (1) {
- printf("%s➜ %s%s%s ", "\x1B[1;32m", "\x1B[1;36m", grass->work_dir_name, "\x1B[1;0m");
- char buf[256];
- if (earth->tty_read(buf, 256) == 0) continue;
-
  struct proc_request req;
  struct proc_reply reply;
 
- if (strcmp(buf, "pwd") == 0) {
- printf("%s\r\n", work_dir);
- } else if (strcmp(buf, "clear") == 0) {
+ if (strcmp(buf, "clear") == 0) {
  printf("\e[1;1H\e[2J");
  } else if (strcmp(buf, "killall") == 0) {
  req.type = PROC_KILLALL;
  grass->sys_send(GPID_PROCESS, (void*)&req, sizeof(req));
  } else {
- int sender;
  req.type = PROC_SPAWN;
  parse_request(buf, &req);
  grass->sys_send(GPID_PROCESS, (void*)&req, sizeof(req));
- grass->sys_recv(&sender, (void*)&reply, sizeof(reply));
+ grass->sys_recv(NULL, (void*)&reply, sizeof(reply));
 
  if (reply.type != CMD_OK)
  INFO("sys_shell: command causes an error");
  else if (req.argv[req.argc - 1][0] != '&')
  /* Wait for foreground process */
- grass->sys_recv(&sender, (void*)&reply, sizeof(reply));
+ grass->sys_recv(NULL, (void*)&reply, sizeof(reply));
  }
+
+ printf("%s➜ %s%s%s ", "\x1B[1;32m", "\x1B[1;36m", grass->workdir, "\x1B[1;0m");
+ while (earth->tty_read(buf, 256) == 0);
  }
 }

apps/user/cat.c

@@ -17,7 +17,7 @@ int main(int argc, char** argv) {
  }
 
  /* Get the inode number of the file */
- int file_ino = dir_lookup(grass->work_dir_ino, argv[1]);
+ int file_ino = dir_lookup(grass->workdir_ino, argv[1]);
  if (file_ino < 0) {
  INFO("cat: file %s not found", argv[1]);
  return -1;

apps/user/cd.c

@@ -0,0 +1,41 @@
+/*
+ * (C) 2022, Cornell University
+ * All rights reserved.
+ */
+
+/* Author: Yunhao Zhang
+ * Description: a simple cd
+ */
+
+#include "app.h"
+#include <string.h>
+
+int main(int argc, char** argv) {
+ if (argc == 1) {
+ int home_ino = dir_lookup(0, "home/");
+ grass->workdir_ino = dir_lookup(home_ino, "yunhao/");
+ strcpy(grass->workdir, "/home/yunhao");
+ return 0;
+ }
+
+ strcat(argv[1], "/");
+ int dir_ino = dir_lookup(grass->workdir_ino, argv[1]);
+ if (dir_ino == -1) {
+ INFO("cd: directory %s not found", argv[1]);
+ return -1;
+ }
+
+ grass->workdir_ino = dir_ino;
+ if (!strcmp(".", argv[1])) return 0;
+
+ int len = strlen(grass->workdir);
+ if (strcmp("..", argv[1])) {
+ if (len > 1) strcat(grass->workdir, "/");
+ strncat(grass->workdir, argv[1], strlen(argv[1]));
+ } else {
+ while (grass->workdir[len] != '/') grass->workdir[len--] = 0;
+ if (len) grass->workdir[len] = 0;
+ }
+
+ return 0;
+}

apps/user/ls.c

@@ -17,7 +17,7 @@ int main(int argc, char** argv) {
  }
 
  char buf[BLOCK_SIZE];
- file_read(grass->work_dir_ino, 0, buf);
+ file_read(grass->workdir_ino, 0, buf);
 
  /* Remove the inode numbers from the string */
  for (int i = 1; i < strlen(buf); i++)

apps/user/pwd.c

@@ -0,0 +1,15 @@
+/*
+ * (C) 2022, Cornell University
+ * All rights reserved.
+ */
+
+/* Author: Yunhao Zhang
+ * Description: a simple pwd
+ */
+
+#include "app.h"
+
+int main(int argc, char** argv) {
+ printf("%s\r\n", grass->workdir);
+ return 0;
+}

grass/syscall.c

@@ -36,7 +36,7 @@ int sys_recv(int* sender, char* buf, int size) {
  sc->type = SYS_RECV;
  sys_invoke();
  memcpy(buf, sc->msg.content, size);
- *sender = sc->msg.sender;
+ if (sender) *sender = sc->msg.sender;
  return sc->retval;
 }
 

library/egos.h

@@ -26,7 +26,6 @@ struct earth {
  int (*tty_critical)(const char *format, ...);
 };
 
-#define ENV_DIR_LEN 32
 struct grass {
  /* Process control interface */
  int (*proc_alloc)();
@@ -39,8 +38,8 @@ struct grass {
  int (*sys_recv)(int* pid, char* buf, int size);
 
  /* Shell environment variables */
- int work_dir_ino;
- char work_dir_name[ENV_DIR_LEN];
+ int workdir_ino;
+ char workdir[128];
 };
 
 extern struct earth *earth;

tools/mkfs.c

@@ -34,20 +34,23 @@ char* kernel_processes[] = {
 #0: / #1: /home #2: /home/yunhao
 #3: /home/rvr #4: /home/yunhao/README #5: /bin
 #6: /bin/echo #7: /bin/ls #8: /bin/cat
-#9: /bin/clock #10: /bin/crash1 #11: /bin/crash2
+#9: /bin/clock #10: /bin/cd #11:/bin/pwd
+#12: /bin/crash1 #13: /bin/crash2
 */
-#define NINODE 12
+#define NINODE 14
 char* contents[] = {
- ". 0 .. 0 home 1 bin 5 ",
- ". 1 .. 0 yunhao 2 rvr 3 ",
- ". 2 .. 1 README 4 ",
- ". 3 .. 1 ",
+ "./ 0 ../ 0 home/ 1 bin/ 5 ",
+ "./ 1 ../ 0 yunhao/ 2 rvr/ 3 ",
+ "./ 2 ../ 1 README 4 ",
+ "./ 3 ../ 1 ",
  "With only 2K lines of code, egos-2000 implements boot loader, microSD driver, tty driver, memory paging, address translation, interrupt handling, process scheduling and messaging, system call, file system, shell, 7 user commands and the `mkfs/mkrom` tools.",
- ". 5 .. 0 echo 6 ls 7 cat 8 clock 9 crash1 10 crash2 11 ",
+ "./ 5 ../ 0 echo 6 ls 7 cat 8 clock 9 cd 10 pwd 11 crash1 12 crash2 13 ",
  "#../build/release/echo.elf",
  "#../build/release/ls.elf",
  "#../build/release/cat.elf",
  "#../build/release/clock.elf",
+ "#../build/release/cd.elf",
+ "#../build/release/pwd.elf",
  "#../build/release/crash1.elf",
  "#../build/release/crash2.elf",
 };