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实现了打开、关闭、读取文件的功能

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This commit is contained in:
fslongjin
2022-04-27 20:49:10 +08:00
parent 966d67fcde
commit b3ad8405a4
10 changed files with 258 additions and 105 deletions
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66
kernel/syscall/syscall.c
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@ -148,7 +148,7 @@ uint64_t sys_open(struct pt_regs *regs)
return -EISDIR;
// 创建文件描述符
struct vfs_file_t *file_ptr = (struct vfs_f2ile_t *)kmalloc(sizeof(struct vfs_file_t), 0);
struct vfs_file_t *file_ptr = (struct vfs_file_t *)kmalloc(sizeof(struct vfs_file_t), 0);
memset(file_ptr, 0, sizeof(struct vfs_file_t));
int errcode = -1;
@ -202,6 +202,66 @@ uint64_t sys_open(struct pt_regs *regs)
return fd_num;
}
/**
* @brief 关闭文件系统调用
*
* @param fd_num 文件描述符号
*
* @param regs
* @return uint64_t
*/
uint64_t sys_close(struct pt_regs *regs)
{
int fd_num = (int)regs->r8;
kdebug("sys close: fd=%d", fd_num);
// 校验文件描述符范围
if (fd_num < 0 || fd_num > PROC_MAX_FD_NUM)
return -EBADF;
struct vfs_file_t *file_ptr = current_pcb->fds[fd_num];
uint64_t ret;
// If there is a valid close function
if (file_ptr->file_ops && file_ptr->file_ops->close)
ret = file_ptr->file_ops->close(file_ptr->dEntry->dir_inode, file_ptr);
kfree(file_ptr);
current_pcb->fds[fd_num] = NULL;
return 0;
}
/**
* @brief 从文件中读取数据
*
* @param fd_num regs->r8 文件描述符号
* @param buf regs->r9 输出缓冲区
* @param count regs->r10 要读取的字节数
*
* @return uint64_t
*/
uint64_t sys_read(struct pt_regs *regs)
{
int fd_num = (int)regs->r8;
void *buf = (void*)regs->r9;
int64_t count = (int64_t)regs->r10;
// kdebug("sys read: fd=%d", fd_num);
// 校验文件描述符范围
if (fd_num < 0 || fd_num > PROC_MAX_FD_NUM)
return -EBADF;
if (count < 0)
return -EINVAL;
struct vfs_file_t *file_ptr = current_pcb->fds[fd_num];
uint64_t ret;
if (file_ptr->file_ops && file_ptr->file_ops->read)
ret = file_ptr->file_ops->read(file_ptr, (char *)buf, count, &(file_ptr->position));
return ret;
}
ul sys_ahci_end_req(struct pt_regs *regs)
{
ahci_end_request();
@ -221,5 +281,7 @@ system_call_t system_call_table[MAX_SYSTEM_CALL_NUM] =
[0] = system_call_not_exists,
[1] = sys_put_string,
[2] = sys_open,
[3 ... 254] = system_call_not_exists,
[3] = sys_close,
[4] = sys_read,
[5 ... 254] = system_call_not_exists,
[255] = sys_ahci_end_req};

2
kernel/syscall/syscall_num.h
View File

@ -12,5 +12,7 @@
#define SYS_NOT_EXISTS 0
#define SYS_PUT_STRING 1
#define SYS_OPEN 2
#define SYS_CLOSE 3
#define SYS_READ 4
#define SYS_AHCI_END_REQ 255 // AHCI DMA请求结束end_request的系统调用