实现了打开、关闭、读取文件的功能

kernel/driver/disk/ahci/ahci.c

@@ -254,7 +254,7 @@ static bool ahci_read(HBA_PORT *port, uint32_t startl, uint32_t starth, uint32_t
 
     cmdfis->fis_type = FIS_TYPE_REG_H2D;
     cmdfis->c = 1; // Command
-    cmdfis->command = ATA_CMD_READ_DMA_EXT;
+    cmdfis->command = AHCI_CMD_READ_DMA_EXT;
 
     cmdfis->lba0 = (uint8_t)startl;
     cmdfis->lba1 = (uint8_t)(startl >> 8);
@@ -269,7 +269,7 @@ static bool ahci_read(HBA_PORT *port, uint32_t startl, uint32_t starth, uint32_t
     cmdfis->counth = (count >> 8) & 0xFF;
 
     // The below loop waits until the port is no longer busy before issuing a new command
-    while ((port->tfd & (ATA_DEV_BUSY | ATA_DEV_DRQ)) && spin < 1000000)
+    while ((port->tfd & (AHCI_DEV_BUSY | AHCI_DEV_DRQ)) && spin < 1000000)
     {
         spin++;
     }
@@ -281,6 +281,7 @@ static bool ahci_read(HBA_PORT *port, uint32_t startl, uint32_t starth, uint32_t
 
     port->ci = 1 << slot; // Issue command
 
+    current_pcb->flags |= PROC_NEED_SCHED;
     sched_cfs();
     int retval = AHCI_SUCCESS;
     // Wait for completion
@@ -344,7 +345,7 @@ static bool ahci_write(HBA_PORT *port, uint32_t startl, uint32_t starth, uint32_
     FIS_REG_H2D *cmdfis = (FIS_REG_H2D *)(&cmdtbl->cfis);
     cmdfis->fis_type = FIS_TYPE_REG_H2D;
     cmdfis->c = 1; // Command
-    cmdfis->command = ATA_CMD_WRITE_DMA_EXT;
+    cmdfis->command = AHCI_CMD_WRITE_DMA_EXT;
     cmdfis->lba0 = (uint8_t)startl;
     cmdfis->lba1 = (uint8_t)(startl >> 8);
     cmdfis->lba2 = (uint8_t)(startl >> 16);
@@ -359,6 +360,7 @@ static bool ahci_write(HBA_PORT *port, uint32_t startl, uint32_t starth, uint32_
     //    printk("[slot]{%d}", slot);
     port->ci = 1; // Issue command
     
+    current_pcb->flags |= PROC_NEED_SCHED;
     sched_cfs();
     int retval = AHCI_SUCCESS;
 
@@ -432,13 +434,13 @@ static struct ahci_request_packet_t *ahci_make_request(long cmd, uint64_t base_a
     // 由于ahci不需要中断即可读取磁盘，因此end handler为空
     switch (cmd)
     {
-    case ATA_CMD_READ_DMA_EXT:
+    case AHCI_CMD_READ_DMA_EXT:
         pack->blk_pak.end_handler = NULL;
-        pack->blk_pak.cmd = ATA_CMD_READ_DMA_EXT;
+        pack->blk_pak.cmd = AHCI_CMD_READ_DMA_EXT;
         break;
-    case ATA_CMD_WRITE_DMA_EXT:
+    case AHCI_CMD_WRITE_DMA_EXT:
         pack->blk_pak.end_handler = NULL;
-        pack->blk_pak.cmd = ATA_CMD_WRITE_DMA_EXT;
+        pack->blk_pak.cmd = AHCI_CMD_WRITE_DMA_EXT;
         break;
     default:
         pack->blk_pak.end_handler = NULL;
@@ -485,10 +487,10 @@ static long ahci_query_disk()
     
     switch (pack->blk_pak.cmd)
     {
-    case ATA_CMD_READ_DMA_EXT:
+    case AHCI_CMD_READ_DMA_EXT:
         ret_val = ahci_read(&(ahci_devices[pack->ahci_ctrl_num].hba_mem->ports[pack->port_num]), pack->blk_pak.LBA_start & 0xFFFFFFFF, ((pack->blk_pak.LBA_start) >> 32) & 0xFFFFFFFF, pack->blk_pak.count, pack->blk_pak.buffer_vaddr);
         break;
-    case ATA_CMD_WRITE_DMA_EXT:
+    case AHCI_CMD_WRITE_DMA_EXT:
         ret_val = ahci_write(&(ahci_devices[pack->ahci_ctrl_num].hba_mem->ports[pack->port_num]), pack->blk_pak.LBA_start & 0xFFFFFFFF, ((pack->blk_pak.LBA_start) >> 32) & 0xFFFFFFFF, pack->blk_pak.count, pack->blk_pak.buffer_vaddr);
         break;
     default:
@@ -530,7 +532,7 @@ static long ahci_transfer(long cmd, uint64_t base_addr, uint64_t count, uint64_t
 {
     struct ahci_request_packet_t *pack = NULL;
 
-    if (cmd == ATA_CMD_READ_DMA_EXT || cmd == ATA_CMD_WRITE_DMA_EXT)
+    if (cmd == AHCI_CMD_READ_DMA_EXT || cmd == AHCI_CMD_WRITE_DMA_EXT)
     {
         pack = ahci_make_request(cmd, base_addr, count, buf, ahci_ctrl_num, port_num);
         ahci_submit(pack);

kernel/driver/disk/ahci/ahci.h

@@ -17,11 +17,11 @@
 #define HBA_PxCMD_FR 0x4000
 #define HBA_PxCMD_CR 0x8000
 
-#define ATA_DEV_BUSY 0x80
+#define AHCI_DEV_BUSY 0x80
-#define ATA_DEV_DRQ 0x08
+#define AHCI_DEV_DRQ 0x08
 
-#define ATA_CMD_READ_DMA_EXT 0x25
+#define AHCI_CMD_READ_DMA_EXT 0x25
-#define ATA_CMD_WRITE_DMA_EXT 0x30
+#define AHCI_CMD_WRITE_DMA_EXT 0x30
 
 #define HBA_PxIS_TFES (1 << 30) /* TFES - Task File Error Status */
 

kernel/filesystem/MBR.c

@@ -14,7 +14,7 @@ struct MBR_disk_partition_table_t *MBR_read_partition_table(uint8_t ahci_ctrl_nu
 {
     unsigned char buf[512];
     memset(buf, 0, 512);
-    ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, 0, 1, (uint64_t)&buf, ahci_ctrl_num, ahci_port_num);
+    ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, 0, 1, (uint64_t)&buf, ahci_ctrl_num, ahci_port_num);
     MBR_partition_tables[ahci_ctrl_num][ahci_port_num] = *(struct MBR_disk_partition_table_t *)buf;
     return &MBR_partition_tables[ahci_ctrl_num][ahci_port_num];
 }

kernel/filesystem/VFS/VFS.h

@@ -127,8 +127,8 @@ struct vfs_file_operations_t
 {
     long (*open)(struct vfs_index_node_t *inode, struct vfs_file_t *file_ptr);
     long (*close)(struct vfs_index_node_t *inode, struct vfs_file_t *file_ptr);
-    long (*read)(struct vfs_file_t *file_ptr, char *buf, uint64_t buf_size, long *position);
+    long (*read)(struct vfs_file_t *file_ptr, char *buf, uint64_t count, long *position);
-    long (*write)(struct vfs_file_t *file_ptr, char *buf, uint64_t buf_size, long *position);
+    long (*write)(struct vfs_file_t *file_ptr, char *buf, uint64_t count, long *position);
     long (*lseek)(struct vfs_file_t *file_ptr, long offset, long origin);
     long (*ioctl)(struct vfs_index_node_t *inode, struct vfs_file_t *file_ptr, uint64_t cmd, uint64_t arg);
 };

kernel/filesystem/fat32/fat32.c

@@ -4,6 +4,7 @@
 #include <filesystem/MBR.h>
 #include <process/spinlock.h>
 #include <mm/slab.h>
+#include <common/errno.h>
 
 struct vfs_super_block_operations_t fat32_sb_ops;
 struct vfs_dir_entry_operations_t fat32_dEntry_ops;
@@ -30,7 +31,7 @@ struct vfs_superblock_t *fat32_register_partition(uint8_t ahci_ctrl_num, uint8_t
     uint8_t buf[512] = {0};
 
     // 读取文件系统的boot扇区
-    ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, DPT->DPTE[part_num].starting_LBA, 1, (uint64_t)&buf, ahci_ctrl_num, ahci_port_num);
+    ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, DPT->DPTE[part_num].starting_LBA, 1, (uint64_t)&buf, ahci_ctrl_num, ahci_port_num);
 
     // 挂载文件系统到vfs
     return vfs_mount_fs("FAT32", (void *)(&DPT->DPTE[part_num]), VFS_DPT_MBR, buf, ahci_ctrl_num, ahci_port_num, part_num);
@@ -47,17 +48,17 @@ uint32_t fat32_read_FAT_entry(fat32_sb_info_t *fsbi, uint32_t cluster)
 {
     // 计算每个扇区内含有的FAT表项数
     // FAT每项4bytes
-    uint32_t fat_ent_per_sec = (fsbi->bootsector.BPB_BytesPerSec >> 2); // 该值应为2的n次幂
+    uint32_t fat_ent_per_sec = (fsbi->bytes_per_sec >> 2); // 该值应为2的n次幂
+    
     uint32_t buf[256];
-    memset(buf, 0, fsbi->bootsector.BPB_BytesPerSec);
+    memset(buf, 0, fsbi->bytes_per_sec);
 
     // 读取一个sector的数据，
-    ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
+    ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
                             (uint64_t)&buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
 
     // 返回下一个fat表项的值（也就是下一个cluster）
     return buf[cluster & (fat_ent_per_sec - 1)] & 0x0fffffff;
-    ;
 }
 
 /**
@@ -76,14 +77,14 @@ uint32_t fat32_write_FAT_entry(fat32_sb_info_t *fsbi, uint32_t cluster, uint32_t
     uint32_t buf[256];
     memset(buf, 0, fsbi->bootsector.BPB_BytesPerSec);
 
-    ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
+    ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
                             (uint64_t)&buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
 
     buf[cluster & (fat_ent_per_sec - 1)] = (buf[cluster & (fat_ent_per_sec - 1)] & 0xf0000000) | (value & 0x0fffffff);
     // 向FAT1和FAT2写入数据
-    ahci_operation.transfer(ATA_CMD_WRITE_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
+    ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, fsbi->FAT1_base_sector + (cluster / fat_ent_per_sec), 1,
                             (uint64_t)&buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
-    ahci_operation.transfer(ATA_CMD_WRITE_DMA_EXT, fsbi->FAT2_base_sector + (cluster / fat_ent_per_sec), 1,
+    ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, fsbi->FAT2_base_sector + (cluster / fat_ent_per_sec), 1,
                             (uint64_t)&buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
 
     return 0;
@@ -120,8 +121,8 @@ struct vfs_dir_entry_t *fat32_lookup(struct vfs_index_node_t *parent_inode, stru
         // kdebug("sector=%d",sector);
 
         // 读取父目录项的起始簇数据
-        ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
+        ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
-        // ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, sector, fat32_part_info[part_id].bootsector.BPB_SecPerClus, (uint64_t)buf, fat32_part_info[part_id].ahci_ctrl_num, fat32_part_info[part_id].ahci_port_num);
+        // ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, sector, fat32_part_info[part_id].bootsector.BPB_SecPerClus, (uint64_t)buf, fat32_part_info[part_id].ahci_ctrl_num, fat32_part_info[part_id].ahci_port_num);
 
         tmp_dEntry = (struct fat32_Directory_t *)buf;
 
@@ -344,7 +345,6 @@ find_lookup_success:; // 找到目标dentry
     return dest_dentry;
 }
 
-
 /**
  * @brief 创建fat32文件系统的超级块
  *
@@ -396,7 +396,7 @@ struct vfs_superblock_t *fat32_read_superblock(void *DPTE, uint8_t DPT_type, voi
 
     // fsinfo扇区的信息
     memset(&fsbi->fsinfo, 0, sizeof(struct fat32_FSInfo_t));
-    ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, MBR_DPTE->starting_LBA + fbs->BPB_FSInfo, 1, (uint64_t)&fsbi->fsinfo, ahci_ctrl_num, ahci_port_num);
+    ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, MBR_DPTE->starting_LBA + fbs->BPB_FSInfo, 1, (uint64_t)&fsbi->fsinfo, ahci_ctrl_num, ahci_port_num);
     printk_color(BLUE, BLACK, "FAT32 FSInfo\n\tFSI_LeadSig:%#018lx\n\tFSI_StrucSig:%#018lx\n\tFSI_Free_Count:%#018lx\n", fsbi->fsinfo.FSI_LeadSig, fsbi->fsinfo.FSI_StrucSig, fsbi->fsinfo.FSI_Free_Count);
 
     // 初始化超级块的dir entry
@@ -485,7 +485,7 @@ void fat32_write_inode(struct vfs_index_node_t *inode)
 
     uint8_t *buf = (uint8_t *)kmalloc(fsbi->bytes_per_clus, 0);
     memset(buf, 0, sizeof(fsbi->bytes_per_clus));
-    ahci_operation.transfer(ATA_CMD_READ_DMA_EXT, fLBA, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
+    ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, fLBA, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
 
     // 计算目标dEntry所在的位置
     struct fat32_Directory_t *fdEntry = (struct fat32_Directory_t *)((uint64_t)buf + finode->dEntry_location_clus_offset);
@@ -496,7 +496,7 @@ void fat32_write_inode(struct vfs_index_node_t *inode)
     fdEntry->DIR_FstClusHI = (finode->first_clus >> 16) | (fdEntry->DIR_FstClusHI & 0xf000);
 
     // 将dir entry写回磁盘
-    ahci_operation.transfer(ATA_CMD_WRITE_DMA_EXT, fLBA, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
+    ahci_operation.transfer(AHCI_CMD_WRITE_DMA_EXT, fLBA, fsbi->sec_per_clus, (uint64_t)buf, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
 
     kfree(buf);
 }
@@ -546,14 +546,95 @@ long fat32_open(struct vfs_index_node_t *inode, struct vfs_file_t *file_ptr)
 // todo: close
 long fat32_close(struct vfs_index_node_t *inode, struct vfs_file_t *file_ptr)
 {
+    return VFS_SUCCESS;
 }
 
-// todo: read
+/**
-long fat32_read(struct vfs_file_t *file_ptr, char *buf, uint64_t buf_size, long *position)
+ * @brief 从fat32文件系统读取数据
+ * 
+ * @param file_ptr 文件描述符
+ * @param buf 输出缓冲区
+ * @param count 要读取的字节数
+ * @param position 文件指针位置
+ * @return long 执行成功：传输的字节数量    执行失败：错误码（小于0）
+ */
+long fat32_read(struct vfs_file_t *file_ptr, char *buf, uint64_t count, long *position)
 {
+
+    struct fat32_inode_info_t *finode = (struct fat32_inode_info_t *)(file_ptr->dEntry->dir_inode->private_inode_info);
+    fat32_sb_info_t *fsbi = (fat32_sb_info_t *)(file_ptr->dEntry->dir_inode->sb->private_sb_info);
+
+    // First cluster num of the file
+    uint64_t cluster = finode->first_clus;
+
+    // kdebug("fsbi->bytes_per_clus=%d", fsbi->bytes_per_clus);
+
+    // clus offset in file
+    uint64_t total_clus_of_file = (*position) / fsbi->bytes_per_clus;
+    // bytes offset in clus
+    uint64_t bytes_offset = (*position) % fsbi->bytes_per_clus;
+
+    if (!cluster)
+        return -EFAULT;
+
+    // find the actual cluster on disk of the specified position
+    for (int i = 0; i < total_clus_of_file; ++i)
+        cluster = fat32_read_FAT_entry(fsbi, cluster);
+
+    // 如果需要读取的数据边界大于文件大小
+    if (*position + count > file_ptr->dEntry->dir_inode->file_size)
+        count = file_ptr->dEntry->dir_inode->file_size - *position;
+
+    // 剩余还需要传输的字节数量
+    uint64_t bytes_remain = count;
+
+    // alloc buffer memory space for ahci transfer
+    void *tmp_buffer = kmalloc(fsbi->bytes_per_clus, 0);
+
+    int64_t retval = 0;
+    do
+    {
+
+        memset(tmp_buffer, 0, fsbi->bytes_per_clus);
+        uint64_t sector = fsbi->first_data_sector + (cluster - 2) * fsbi->sec_per_clus;
+        // 读取一个簇的数据
+        int errno = ahci_operation.transfer(AHCI_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)tmp_buffer, fsbi->ahci_ctrl_num, fsbi->ahci_port_num);
+        if (errno != AHCI_SUCCESS)
+        {
+            kerror("FAT32 FS(read) error!");
+            retval = -EIO;
+            break;
+        }
+
+        int64_t step_trans_len = 0; // 当前循环传输的字节数
+        if (bytes_remain > (fsbi->bytes_per_clus - bytes_offset))
+            step_trans_len = (fsbi->bytes_per_clus - bytes_offset);
+        else
+            step_trans_len = bytes_remain;
+
+        if (((uint64_t)buf) < USER_MAX_LINEAR_ADDR)
+            copy_to_user(buf, tmp_buffer + bytes_offset, step_trans_len);
+        else
+            memcpy(buf, tmp_buffer, step_trans_len);
+
+        bytes_remain -= step_trans_len;
+        buf += step_trans_len;
+        bytes_offset -= bytes_offset;
+
+        *position += step_trans_len; // 更新文件指针
+
+        cluster = fat32_read_FAT_entry(fsbi, cluster);
+    } while (bytes_remain && (cluster < 0x0ffffff8) && cluster != 0);
+
+    kfree(tmp_buffer);
+
+    if(!bytes_remain)
+        retval = count;
+
+    return retval;
 }
 // todo: write
-long fat32_write(struct vfs_file_t *file_ptr, char *buf, uint64_t buf_size, long *position)
+long fat32_write(struct vfs_file_t *file_ptr, char *buf, uint64_t count, long *position)
 {
 }
 // todo: lseek

kernel/mm/mm.h

@@ -9,7 +9,7 @@
 // 内核层的起始地址
 #define PAGE_OFFSET (0xffff800000000000UL)
 #define KERNEL_BASE_LINEAR_ADDR (0xffff800000000000UL)
-#define USER_MAX_LINEAR_ADDR 0x00007fffffffffffUL;
+#define USER_MAX_LINEAR_ADDR 0x00007fffffffffffUL
 
 #define PAGE_4K_SHIFT 12
 #define PAGE_2M_SHIFT 21

kernel/process/proc.S

@@ -1,5 +1,12 @@
 #include"../common/asm.h"
 
+/**
+ * @brief 导出内核线程的执行引导程序
+ *  目的是还原执行现场(在kernel_thread中伪造的)
+ * 执行到这里时，rsp位于栈顶，然后弹出寄存器值
+ * 弹出之后还要向上移动7个unsigned long的大小，从而弹出额外的信息（详见pt_regs）
+ */
+ 
 ENTRY(kernel_thread_func) 
     popq	%r15	   
     popq	%r14	   

kernel/process/process.c

@@ -85,9 +85,10 @@ void user_level_function()
         : "a"(SYS_PUT_STRING), "m"(addr)
         : "memory", "r8");
     */
-
+    while (1)
+    {
         // 测试sys_open
-    char string[] = "/xx/12.png";
+        char string[] = "a.txt";
         long err_code = 1;
         int zero = 0;
         uint64_t addr = (ul)string;
@@ -105,6 +106,53 @@ void user_level_function()
             : "a"(SYS_OPEN), "m"(addr), "m"(zero), "m"(zero), "m"(zero), "m"(zero), "m"(zero), "m"(zero), "m"(zero)
             : "memory", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", "rcx", "rdx");
 
+        int fd_num = err_code;
+
+        int count = 16;
+        while (count)
+        {
+            uchar buf[128] = {0};
+            // Test sys_read
+            addr = (uint64_t)&buf;
+            __asm__ __volatile__(
+                "movq %2, %%r8 \n\t"
+                "movq %3, %%r9 \n\t"
+                "movq %4, %%r10 \n\t"
+                "movq %5, %%r11 \n\t"
+                "movq %6, %%r12 \n\t"
+                "movq %7, %%r13 \n\t"
+                "movq %8, %%r14 \n\t"
+                "movq %9, %%r15 \n\t"
+                "int $0x80   \n\t"
+                : "=a"(err_code)
+                : "a"(SYS_READ), "m"(fd_num), "m"(addr), "m"(count), "m"(zero), "m"(zero), "m"(zero), "m"(zero), "m"(zero)
+                : "memory", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", "rcx", "rdx");
+            count = err_code;
+            // 将读取到的数据打印出来
+            addr = (ul)buf;
+            __asm__ __volatile__(
+                "movq %2, %%r8 \n\t"
+                "int $0x80   \n\t"
+                : "=a"(err_code)
+                : "a"(SYS_PUT_STRING), "m"(addr)
+                : "memory", "r8");
+        }
+
+        // Test sys_close
+        __asm__ __volatile__(
+            "movq %2, %%r8 \n\t"
+            "movq %3, %%r9 \n\t"
+            "movq %4, %%r10 \n\t"
+            "movq %5, %%r11 \n\t"
+            "movq %6, %%r12 \n\t"
+            "movq %7, %%r13 \n\t"
+            "movq %8, %%r14 \n\t"
+            "movq %9, %%r15 \n\t"
+            "int $0x80   \n\t"
+            : "=a"(err_code)
+            : "a"(SYS_CLOSE), "m"(fd_num), "m"(zero), "m"(zero), "m"(zero), "m"(zero), "m"(zero), "m"(zero), "m"(zero)
+            : "memory", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", "rcx", "rdx");
+    }
     while (1)
         pause();
 }
@@ -204,46 +252,6 @@ ul process_thread_do_exit(ul code)
         ;
 }
 
-/**
- * @brief 导出内核线程的执行引导程序
- *  目的是还原执行现场(在kernel_thread中伪造的)
- * 执行到这里时，rsp位于栈顶，然后弹出寄存器值
- * 弹出之后还要向上移动7个unsigned long的大小，从而弹出额外的信息（详见pt_regs）
- */
-/*
-void kernel_thread_func(void)
-{
-    __asm__ volatile(
-    //"kernel_thread_func:	\n\t"
-    "	popq	%r15	\n\t"
-    "	popq	%r14	\n\t"
-    "	popq	%r13	\n\t"
-    "	popq	%r12	\n\t"
-    "	popq	%r11	\n\t"
-    "	popq	%r10	\n\t"
-    "	popq	%r9	\n\t"
-    "	popq	%r8	\n\t"
-    "	popq	%rbx	\n\t"
-    "	popq	%rcx	\n\t"
-    "	popq	%rdx	\n\t"
-    "	popq	%rsi	\n\t"
-    "	popq	%rdi	\n\t"
-    "	popq	%rbp	\n\t"
-    "	popq	%rax	\n\t"
-    "	movq	%rax,	%ds	\n\t"
-    "	popq	%rax		\n\t"
-    "	movq	%rax,	%es	\n\t"
-    "	popq	%rax		\n\t"
-    "	addq	$0x38,	%rsp	\n\t"
-    /////////////////////////////////
-    "	movq	%rdx,	%rdi	\n\t"
-    "	callq	*%rbx		\n\t"
-    "	movq	%rax,	%rdi	\n\t"
-    "	callq	process_thread_do_exit		\n\t");
-}
-
-*/
-
 /**
  * @brief 初始化内核进程
  *
@@ -302,15 +310,6 @@ void process_init()
 
     initial_mm.stack_start = _stack_start;
 
-    /*
-    // 向MSR寄存器组中的 IA32_SYSENTER_CS寄存器写入内核的代码段的地址
-    wrmsr(0x174, KERNEL_CS);
-    // 向MSR寄存器组中的 IA32_SYSENTER_ESP寄存器写入内核进程的rbp（在syscall入口中会将rsp减去相应的数值）
-    wrmsr(0x175, current_pcb->thread->rbp);
-
-    // 向MSR寄存器组中的 IA32_SYSENTER_EIP寄存器写入系统调用入口的地址。
-    wrmsr(0x176, (ul)system_call);
-    */
     // 初始化进程和tss
     // set_tss64((uint *)phys_2_virt(TSS64_Table), initial_thread.rbp, initial_tss[0].rsp1, initial_tss[0].rsp2, initial_tss[0].ist1, initial_tss[0].ist2, initial_tss[0].ist3, initial_tss[0].ist4, initial_tss[0].ist5, initial_tss[0].ist6, initial_tss[0].ist7);
 

kernel/syscall/syscall.c

@@ -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};

kernel/syscall/syscall_num.h

@@ -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