From 37669ebf87fc0086cc00695790de4ab6979933cc Mon Sep 17 00:00:00 2001 From: fslongjin Date: Wed, 25 May 2022 22:50:32 +0800 Subject: [PATCH] =?UTF-8?q?:new:=20cd=E5=91=BD=E4=BB=A4?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- kernel/syscall/syscall.c | 70 ++++++++++++++++++- kernel/syscall/syscall_num.h | 1 + user/apps/shell/Makefile | 5 +- user/apps/shell/cmd.c | 122 +++++++++++++++++++++++++++++++++- user/apps/shell/cmd.h | 3 + user/apps/shell/cmd_help.c | 23 +++++++ user/apps/shell/cmd_help.h | 10 +++ user/apps/shell/shell.c | 32 +++++---- user/libs/libc/Makefile | 7 +- user/libs/libc/malloc.c | 15 +++-- user/libs/libc/string.c | 109 ++++++++++++++++++++++++++++++ user/libs/libc/string.h | 84 ++++++++--------------- user/libs/libc/unistd.c | 30 +++++++++ user/libs/libc/unistd.h | 25 ++++--- user/libs/libsystem/syscall.h | 1 + 15 files changed, 443 insertions(+), 94 deletions(-) create mode 100644 user/apps/shell/cmd_help.c create mode 100644 user/apps/shell/cmd_help.h create mode 100644 user/libs/libc/string.c diff --git a/kernel/syscall/syscall.c b/kernel/syscall/syscall.c index bf253698..7058de50 100644 --- a/kernel/syscall/syscall.c +++ b/kernel/syscall/syscall.c @@ -140,7 +140,7 @@ uint64_t sys_open(struct pt_regs *regs) printk_color(ORANGE, BLACK, "Can`t find file\n"); kfree(path); - if (dentry == NULL) + if (dentry == NULL) return -ENOENT; // 暂时认为目标是目录是一种错误 @@ -445,7 +445,7 @@ uint64_t sys_sbrk(struct pt_regs *regs) /** * @brief 重启计算机 * - * @return + * @return */ uint64_t sys_reboot(struct pt_regs *regs) { @@ -455,6 +455,69 @@ uint64_t sys_reboot(struct pt_regs *regs) return 0; } +/** + * @brief 切换工作目录 + * + * @param dest_path 目标路径 + * @return ++--------------+------------------------+ +| 返回码 | 描述 | ++--------------+------------------------+ +| 0 | 成功 | +| EACCESS | 权限不足 | +| ELOOP | 解析path时遇到路径循环 | +| ENAMETOOLONG | 路径名过长 | +| ENOENT | 目标文件或目录不存在 | +| ENODIR | 检索期间发现非目录项 | +| ENOMEM | 系统内存不足 | +| EFAULT | 错误的地址 | +| ENAMETOOLONG | 路径过长 | ++--------------+------------------------+ + */ +uint64_t sys_chdir(struct pt_regs *regs) +{ + char *dest_path = (char *)regs->r8; + // kdebug("dest_path=%s", dest_path); + // 检查目标路径是否为NULL + if (dest_path == NULL) + return -EFAULT; + + // 计算输入的路径长度 + int dest_path_len = strnlen_user(dest_path, PAGE_4K_SIZE); + + + // 长度小于等于0 + if (dest_path_len <= 0) + return -EFAULT; + else if (dest_path_len >= PAGE_4K_SIZE) + return -ENAMETOOLONG; + + // 为路径字符串申请空间 + char *path = kmalloc(dest_path_len + 1, 0); + // 系统内存不足 + if (path == NULL) + return -ENOMEM; + + memset(path, 0, dest_path_len + 1); + + // 将字符串从用户空间拷贝进来, +1是为了拷贝结尾的\0 + strncpy_from_user(path, dest_path, dest_path_len + 1); + + + struct vfs_dir_entry_t *dentry = vfs_path_walk(path, 0); + + kfree(path); + + if (dentry == NULL) + return -ENOENT; + + // 目标不是目录 + if (dentry->dir_inode->attribute != VFS_ATTR_DIR) + return -ENOTDIR; + + return 0; +} + ul sys_ahci_end_req(struct pt_regs *regs) { ahci_end_request(); @@ -483,5 +546,6 @@ system_call_t system_call_table[MAX_SYSTEM_CALL_NUM] = [9] = sys_brk, [10] = sys_sbrk, [11] = sys_reboot, - [12 ... 254] = system_call_not_exists, + [12] = sys_chdir, + [13 ... 254] = system_call_not_exists, [255] = sys_ahci_end_req}; diff --git a/kernel/syscall/syscall_num.h b/kernel/syscall/syscall_num.h index 13a180f5..0fcbd670 100644 --- a/kernel/syscall/syscall_num.h +++ b/kernel/syscall/syscall_num.h @@ -21,5 +21,6 @@ #define SYS_BRK 9 #define SYS_SBRK 10 #define SYS_REBOOT 11 // 重启 +#define SYS_CHDIR 12 // 切换工作目录 #define SYS_AHCI_END_REQ 255 // AHCI DMA请求结束end_request的系统调用 \ No newline at end of file diff --git a/user/apps/shell/Makefile b/user/apps/shell/Makefile index 1828179f..c2035788 100644 --- a/user/apps/shell/Makefile +++ b/user/apps/shell/Makefile @@ -1,7 +1,10 @@ -all: shell.o cmd.o +all: shell.o cmd.o cmd_help.o shell.o: shell.c gcc $(CFLAGS) -c shell.c -o shell.o cmd.o: cmd.c gcc $(CFLAGS) -c cmd.c -o cmd.o + +cmd_help.o: cmd_help.c + gcc $(CFLAGS) -c cmd_help.c -o cmd_help.o diff --git a/user/apps/shell/cmd.c b/user/apps/shell/cmd.c index dee57660..43d09390 100644 --- a/user/apps/shell/cmd.c +++ b/user/apps/shell/cmd.c @@ -3,6 +3,12 @@ #include #include #include +#include +#include +#include +#include + +#include "cmd_help.h" // 当前工作目录（在main_loop中初始化） char *shell_current_path = NULL; @@ -22,6 +28,7 @@ struct built_in_cmd_t shell_cmds[] = {"rmdir", shell_cmd_rmdir}, {"reboot", shell_cmd_reboot}, {"touch", shell_cmd_touch}, + {"help", shell_help}, }; // 总共的内建命令数量 @@ -69,8 +76,112 @@ void shell_run_built_in_command(int index, int argc, char **argv) * @param argv * @return int */ -// todo: -int shell_cmd_cd(int argc, char **argv) {} + +int shell_cmd_cd(int argc, char **argv) +{ + + int current_dir_len = strlen(shell_current_path); + if (argc < 2) + { + shell_help_cd(); + goto done; + } + // 进入当前文件夹 + if (!strcmp(".", argv[1])) + goto done; + + // 进入父目录 + if (!strcmp("..", argv[1])) + { + + // 当前已经是根目录 + if (!strcmp("/", shell_current_path)) + goto done; + + // 返回到父目录 + int index = current_dir_len - 1; + for (; index > 1; --index) + { + if (shell_current_path[index] == '/') + break; + } + shell_current_path[index] = '\0'; + + // printf("switch to \" %s \"\n", shell_current_path); + goto done; + } + + int dest_len = strlen(argv[1]); + // 路径过长 + if (dest_len >= SHELL_CWD_MAX_SIZE - 1) + { + printf("ERROR: Path too long!\n"); + goto fail; + } + + if (argv[1][0] == '/') + { + // ======进入绝对路径===== + int ec = chdir(argv[1]); + if (ec == -1) + ec = errno; + if (ec == 0) + { + // 获取新的路径字符串 + char *new_path = (char *)malloc(dest_len + 2); + memset(new_path, 0, dest_len + 2); + strncpy(new_path, argv[1], dest_len); + + // 释放原有的路径字符串的内存空间 + free(shell_current_path); + + shell_current_path = new_path; + + shell_current_path[dest_len] = '\0'; + return 0; + } + else + goto fail;; // 出错则直接忽略 + } + else + { + int new_len = current_dir_len + dest_len; + // ======进入相对路径===== + if (new_len >= SHELL_CWD_MAX_SIZE - 1) + { + printf("ERROR: Path too long!\n"); + goto fail; + } + + // 拼接出新的字符串 + char *new_path = (char *)malloc(new_len + 2); + memset(new_path, 0, sizeof(new_path)); + strncpy(new_path, shell_current_path, current_dir_len); + + if (current_dir_len > 1) + new_path[current_dir_len] = '/'; + strcat(new_path, argv[1]); + + if (chdir(new_path) == 0) // 成功切换目录 + { + free(shell_current_path); + new_path[new_len] = '\0'; + shell_current_path = new_path; + goto done; + } + else + { + printf("ERROR: Cannot switch to directory: %s\n", new_path); + goto fail; + } + } + +fail:; +done:; + // 释放参数所占的内存 + free(argv); + return 0; +} /** * @brief 查看文件夹下的文件列表 @@ -80,7 +191,10 @@ int shell_cmd_cd(int argc, char **argv) {} * @return int */ // todo: -int shell_cmd_ls(int argc, char **argv) {} +int shell_cmd_ls(int argc, char **argv) +{ + return 0; +} /** * @brief 显示当前工作目录的命令 @@ -93,6 +207,8 @@ int shell_cmd_pwd(int argc, char **argv) { if (shell_current_path) printf("%s\n", shell_current_path); + + free(argv); } /** diff --git a/user/apps/shell/cmd.h b/user/apps/shell/cmd.h index 0cbe9eef..507b143a 100644 --- a/user/apps/shell/cmd.h +++ b/user/apps/shell/cmd.h @@ -1,5 +1,8 @@ #pragma once +// cwd字符串的最大大小 +#define SHELL_CWD_MAX_SIZE 256 + /** * @brief shell内建命令结构体 * diff --git a/user/apps/shell/cmd_help.c b/user/apps/shell/cmd_help.c new file mode 100644 index 00000000..34f2047f --- /dev/null +++ b/user/apps/shell/cmd_help.c @@ -0,0 +1,23 @@ +#include "cmd_help.h" +#include +struct help_table_item_t +{ + void (*func)(); +}; +struct help_table_item_t help_table[] = { + {shell_help_cd}, +}; + +static const int help_table_num = sizeof(help_table) / sizeof(struct help_table_item_t); + +void shell_help() +{ + printf("Help:\n"); + for (int i = 0; i < help_table_num; ++i) + help_table[i].func(); +} + +void shell_help_cd() +{ + printf("Example of cd: cd [destination]\n"); +} \ No newline at end of file diff --git a/user/apps/shell/cmd_help.h b/user/apps/shell/cmd_help.h new file mode 100644 index 00000000..fa2b6096 --- /dev/null +++ b/user/apps/shell/cmd_help.h @@ -0,0 +1,10 @@ +#pragma once + +#include "cmd.h" +void shell_help(); + +/** + * @brief cd命令的帮助信息 + * + */ +void shell_help_cd(); \ No newline at end of file diff --git a/user/apps/shell/shell.c b/user/apps/shell/shell.c index 6a26d17f..a2e2624b 100644 --- a/user/apps/shell/shell.c +++ b/user/apps/shell/shell.c @@ -42,9 +42,10 @@ static void main_loop(int kb_fd) unsigned char input_buffer[INPUT_BUFFER_SIZE] = {0}; // 初始化当前工作目录的路径 - shell_current_path = (char *)malloc(256); - memset(shell_current_path, 0, 256); - shell_current_path = "/"; + shell_current_path = (char *)malloc(3); + memset(shell_current_path, 0, 3); + shell_current_path[0] = '/'; + shell_current_path[1] = '\0'; // shell命令行的主循环 while (true) @@ -52,17 +53,22 @@ static void main_loop(int kb_fd) int argc = 0; char **argv; - printf("[DragonOS] # "); + printf("[DragonOS] %s # ", shell_current_path); memset(input_buffer, 0, INPUT_BUFFER_SIZE); // 循环读取每一行到buffer - shell_readline(kb_fd, input_buffer); + int count = shell_readline(kb_fd, input_buffer); - int cmd_num = parse_command(input_buffer, &argc, &argv); - printf("\n"); - if (cmd_num >= 0) - shell_run_built_in_command(cmd_num, argc, argv); - + if (count) + { + int cmd_num = parse_command(input_buffer, &argc, &argv); + printf("\n"); + if (cmd_num >= 0) + shell_run_built_in_command(cmd_num, argc, argv); + + } + else + printf("\n"); } } @@ -120,13 +126,14 @@ int shell_readline(int fd, char *buf) */ int parse_command(char *buf, int *argc, char ***argv) { + // printf("parse command\n"); int index = 0; // 当前访问的是buf的第几位 // 去除命令前导的空格 while (index < INPUT_BUFFER_SIZE && buf[index] == ' ') ++index; // 计算参数数量 - for (int i = index; i < INPUT_BUFFER_SIZE - 1; ++i) + for (int i = index; i < (INPUT_BUFFER_SIZE - 1); ++i) { // 到达了字符串末尾 if (!buf[i]) @@ -140,13 +147,12 @@ int parse_command(char *buf, int *argc, char ***argv) // 为指向每个指令的指针分配空间 *argv = (char **)malloc(sizeof(char **) * (*argc)); memset(*argv, 0, sizeof(char **) * (*argc)); - // 将每个命令都单独提取出来 for (int i = 0; i < *argc && index < INPUT_BUFFER_SIZE; ++i) { // 提取出命令，以空格作为分割 *((*argv) + i) = &buf[index]; - while (index < INPUT_BUFFER_SIZE - 1 && buf[index] && buf[index] != ' ') + while (index < (INPUT_BUFFER_SIZE - 1) && buf[index] && buf[index] != ' ') ++index; buf[index++] = '\0'; diff --git a/user/libs/libc/Makefile b/user/libs/libc/Makefile index dc644236..85d40d2a 100644 --- a/user/libs/libc/Makefile +++ b/user/libs/libc/Makefile @@ -5,7 +5,7 @@ CFLAGS += -I . libc_sub_dirs=math -libc: unistd.o fcntl.o malloc.o errno.o printf.o stdlib.o ctype.o +libc: unistd.o fcntl.o malloc.o errno.o printf.o stdlib.o ctype.o string.o @list='$(libc_sub_dirs)'; for subdir in $$list; do \ echo "make all in $$subdir";\ cd $$subdir;\ @@ -32,4 +32,7 @@ stdlib.o: stdlib.c gcc $(CFLAGS) -c stdlib.c -o stdlib.o ctype.o: ctype.c - gcc $(CFLAGS) -c ctype.c -o ctype.o \ No newline at end of file + gcc $(CFLAGS) -c ctype.c -o ctype.o + +string.o: string.c + gcc $(CFLAGS) -c string.c -o string.o \ No newline at end of file diff --git a/user/libs/libc/malloc.c b/user/libs/libc/malloc.c index 040e895a..8129ccc1 100644 --- a/user/libs/libc/malloc.c +++ b/user/libs/libc/malloc.c @@ -268,7 +268,7 @@ static void malloc_insert_free_list(malloc_mem_chunk_t *ck) */ void *malloc(ssize_t size) { - + // printf("malloc\n"); // 计算需要分配的块的大小 if (size + sizeof(uint64_t) <= sizeof(malloc_mem_chunk_t)) size = sizeof(malloc_mem_chunk_t); @@ -281,6 +281,7 @@ void *malloc(ssize_t size) if (ck == NULL) // 没有空闲块 { + // printf("no free blocks\n"); // 尝试合并空闲块 malloc_merge_free_chunk(); ck = malloc_query_free_chunk_bf(size); @@ -288,10 +289,12 @@ void *malloc(ssize_t size) // 找到了合适的块 if (ck) goto found; + + // printf("before enlarge\n"); // 找不到合适的块，扩容堆区域 - if (malloc_enlarge(size) == -ENOMEM) return (void *)-ENOMEM; // 内存不足 + malloc_merge_free_chunk(); // 扩容后运行合并，否则会导致碎片 @@ -304,6 +307,7 @@ found:; // printf("ck = %#018lx\n", (uint64_t)ck); if (ck == NULL) return (void *)-ENOMEM; + // printf("ck->prev=%#018lx ck->next=%#018lx\n", ck->prev, ck->next); // 分配空闲块 // 从空闲链表取出 if (ck->prev == NULL) // 当前是链表的第一个块 @@ -321,6 +325,7 @@ found:; // 当前块剩余的空间还能容纳多一个结点的空间，则分裂当前块 if ((int64_t)(ck->length) - size > sizeof(malloc_mem_chunk_t)) { + // printf("seperate\n"); malloc_mem_chunk_t *new_ck = (malloc_mem_chunk_t *)(((uint64_t)ck) + size); new_ck->length = ck->length - size; new_ck->prev = new_ck->next = NULL; @@ -328,7 +333,7 @@ found:; ck->length = size; malloc_insert_free_list(new_ck); } - + // printf("malloc done: %#018lx, length=%#018lx\n", ((uint64_t)ck + sizeof(uint64_t)), ck->length); // 此时链表结点的指针的空间被分配出去 return (void *)((uint64_t)ck + sizeof(uint64_t)); } @@ -367,13 +372,13 @@ static void release_brk() * * @param ptr 堆内存的指针 */ -void free(void *ptr) +void free(void *ptr) { // 找到结点（此时prev和next都处于未初始化的状态） malloc_mem_chunk_t *ck = (malloc_mem_chunk_t *)((uint64_t)ptr - sizeof(uint64_t)); // printf("free(): addr = %#018lx\t len=%#018lx\n", (uint64_t)ck, ck->length); count_last_free_size += ck->length; - + malloc_insert_free_list(ck); if (count_last_free_size > PAGE_2M_SIZE) diff --git a/user/libs/libc/string.c b/user/libs/libc/string.c new file mode 100644 index 00000000..3e41c8e9 --- /dev/null +++ b/user/libs/libc/string.c @@ -0,0 +1,109 @@ +#include "string.h" + +size_t strlen(const char *s) +{ + register int __res = 0; + while (s[__res] != '\0') + { + ++__res; + } + return __res; +} + +int strcmp(const char *FirstPart, const char *SecondPart) +{ + register int __res; + __asm__ __volatile__("cld \n\t" + "1: \n\t" + "lodsb \n\t" + "scasb \n\t" + "jne 2f \n\t" + "testb %%al, %%al \n\t" + "jne 1b \n\t" + "xorl %%eax, %%eax \n\t" + "jmp 3f \n\t" + "2: \n\t" + "movl $1, %%eax \n\t" + "jl 3f \n\t" + "negl %%eax \n\t" + "3: \n\t" + : "=a"(__res) + : "D"(FirstPart), "S"(SecondPart) + :); + return __res; +} + +void *memset(void *dst, unsigned char C, uint64_t size) +{ + + int d0, d1; + unsigned long tmp = C * 0x0101010101010101UL; + __asm__ __volatile__("cld \n\t" + "rep \n\t" + "stosq \n\t" + "testb $4, %b3 \n\t" + "je 1f \n\t" + "stosl \n\t" + "1:\ttestb $2, %b3 \n\t" + "je 2f\n\t" + "stosw \n\t" + "2:\ttestb $1, %b3 \n\t" + "je 3f \n\t" + "stosb \n\t" + "3: \n\t" + : "=&c"(d0), "=&D"(d1) + : "a"(tmp), "q"(size), "0"(size / 8), "1"(dst) + : "memory"); + return dst; +} + +/** + * @brief 拷贝指定字节数的字符串 + * + * @param dst 目标地址 + * @param src 源字符串 + * @param Count 字节数 + * @return char* + */ +char *strncpy(char *dst, char *src, long Count) +{ + __asm__ __volatile__("cld \n\t" + "1: \n\t" + "decq %2 \n\t" + "js 2f \n\t" + "lodsb \n\t" + "stosb \n\t" + "testb %%al, %%al \n\t" + "jne 1b \n\t" + "rep \n\t" + "stosb \n\t" + "2: \n\t" + : + : "S"(src), "D"(dst), "c"(Count) + : "ax", "memory"); + return dst; +} + +/** + * @brief 拼接两个字符串（将src接到dest末尾） + * + * @param dest 目标串 + * @param src 源串 + * @return char* + */ +char *strcat(char *dest, const char *src) +{ + unsigned int dest_size = strlen(dest); + unsigned int src_size = strlen(src); + + char *d = dest; + + for (size_t i = 0; i < src_size; i++) + { + d[dest_size + i] = src[i]; + } + + d[dest_size + src_size] = '\0'; + + return dest; +} \ No newline at end of file diff --git a/user/libs/libc/string.h b/user/libs/libc/string.h index 404e394f..33ea2647 100644 --- a/user/libs/libc/string.h +++ b/user/libs/libc/string.h @@ -2,40 +2,14 @@ #include -void *memset(void *dst, unsigned char C, uint64_t size) -{ - - int d0, d1; - unsigned long tmp = C * 0x0101010101010101UL; - __asm__ __volatile__("cld \n\t" - "rep \n\t" - "stosq \n\t" - "testb $4, %b3 \n\t" - "je 1f \n\t" - "stosl \n\t" - "1:\ttestb $2, %b3 \n\t" - "je 2f\n\t" - "stosw \n\t" - "2:\ttestb $1, %b3 \n\t" - "je 3f \n\t" - "stosb \n\t" - "3: \n\t" - : "=&c"(d0), "=&D"(d1) - : "a"(tmp), "q"(size), "0"(size / 8), "1"(dst) - : "memory"); - return dst; -} - -size_t strlen(const char *s) -{ - register size_t __res = 0; - while (s[__res] != '\0') - { - ++__res; - } - return __res; -} - +void *memset(void *dst, unsigned char C, uint64_t size); +/** + * @brief 获取字符串的大小 + * + * @param s 字符串 + * @return size_t 大小 + */ +size_t strlen(const char *s); /* 比较字符串 FirstPart and SecondPart @@ -44,25 +18,23 @@ size_t strlen(const char *s) FirstPart < SecondPart => -1 */ -int strcmp(const char *FirstPart, const char *SecondPart) -{ - register int __res; - __asm__ __volatile__("cld \n\t" - "1: \n\t" - "lodsb \n\t" - "scasb \n\t" - "jne 2f \n\t" - "testb %%al, %%al \n\t" - "jne 1b \n\t" - "xorl %%eax, %%eax \n\t" - "jmp 3f \n\t" - "2: \n\t" - "movl $1, %%eax \n\t" - "jl 3f \n\t" - "negl %%eax \n\t" - "3: \n\t" - : "=a"(__res) - : "D"(FirstPart), "S"(SecondPart) - :); - return __res; -} \ No newline at end of file +int strcmp(const char *FirstPart, const char *SecondPart); + +/** + * @brief 拷贝指定字节数的字符串 + * + * @param dst 目标地址 + * @param src 源字符串 + * @param Count 字节数 + * @return char* + */ +char *strncpy(char *dst, char *src, long Count); + +/** + * @brief 拼接两个字符串（将src接到dest末尾） + * + * @param dest 目标串 + * @param src 源串 + * @return char* + */ +char *strcat(char *dest, const char *src); \ No newline at end of file diff --git a/user/libs/libc/unistd.c b/user/libs/libc/unistd.c index ff5bc813..db5db22c 100644 --- a/user/libs/libc/unistd.c +++ b/user/libs/libc/unistd.c @@ -2,6 +2,7 @@ #include #include #include +#include /** * @brief 关闭文件接口 @@ -105,4 +106,33 @@ void *sbrk(int64_t increment) errno = 0; return (void *)retval; } +} + +/** + * @brief 切换当前工作目录 + * + * @param dest_path 目标目录 + * @return int64_t 成功：0,失败：负值（错误码） + */ +int64_t chdir(char *dest_path) +{ + if (dest_path == NULL) + { + errno = -EFAULT; + return -1; + } + else + { + int retval = syscall_invoke(SYS_CHDIR, (uint64_t)dest_path, 0,0,0,0,0,0,0); + if(retval == 0) + { + errno = 0; + return 0; + } + else + { + errno = retval; + return -1; + } + } } \ No newline at end of file diff --git a/user/libs/libc/unistd.h b/user/libs/libc/unistd.h index 28494b94..de8ff3f6 100644 --- a/user/libs/libc/unistd.h +++ b/user/libs/libc/unistd.h @@ -2,11 +2,6 @@ #include #include - - - - - /** * @brief 关闭文件接口 * @@ -47,15 +42,15 @@ off_t lseek(int fd, off_t offset, int whence); /** * @brief fork当前进程 - * - * @return pid_t + * + * @return pid_t */ pid_t fork(void); /** * @brief fork当前进程，但是与父进程共享VM、flags、fd - * - * @return pid_t + * + * @return pid_t */ pid_t vfork(void); @@ -72,8 +67,16 @@ uint64_t brk(uint64_t end_brk); /** * @brief 将堆内存空间加上offset（注意，该系统调用只应在普通进程中调用，而不能是内核线程） - * + * * @param increment offset偏移量 * @return uint64_t the previous program break */ -void * sbrk(int64_t increment); +void *sbrk(int64_t increment); + +/** + * @brief 切换当前工作目录 + * + * @param dest_path 目标目录 + * @return int64_t 成功：0,失败：负值（错误码） + */ +int64_t chdir(char *dest_path); diff --git a/user/libs/libsystem/syscall.h b/user/libs/libsystem/syscall.h index 75253ce2..1b003cf7 100644 --- a/user/libs/libsystem/syscall.h +++ b/user/libs/libsystem/syscall.h @@ -15,6 +15,7 @@ #define SYS_BRK 9 #define SYS_SBRK 10 #define SYS_REBOOT 11 +#define SYS_CHDIR 12 // 切换工作目录 /** * @brief 用户态系统调用函数