return the result to userspace from syscall

diff --git a/include/system.h b/include/system.h
index 7a071dc4f5f4ed508ce1bc9ee2bebafe599305bf..15ca0506de53ba267655fa7937ddf1310e2ff3b1 100644 (file)
--- a/include/system.h
+++ b/include/system.h
@@ -102,12 +102,13 @@ enum GDTSelectorIndex
 // pushad push eax, ecx, edx, ebx, esp, ebp, esi, edi
 typedef    struct
 {
-    u32    ebx;
-    u32    edx;
-    u32    ecx;
     u32    edi;
     u32    esi;
     u32    ebp;
+    u32    _esp;
+    u32    ebx;
+    u32    edx;
+    u32    ecx;
     u32    eax;    // 因为在系统调用中用来带调用号，就无法传送参数
             // 所以把eax放在这个位置
     u16    ds, _ds;
@@ -116,7 +117,6 @@ typedef    struct
     u16    gs, _gs;
     union
     {
-        u32    sysc_nr;
         u32    irq;
         u32    errcode;
     };
@@ -176,22 +176,10 @@ extern    System system;
     pushl    %fs;    \
     pushl    %es;    \
     pushl    %ds;    \
-    pushl    %eax;    \
-    pushl    %ebp;    \
-    pushl    %esi;    \
-    pushl    %edi;    \
-    pushl    %ecx;    \
-    pushl    %edx;    \
-    pushl    %ebx;
+    pushal;
 
 #define RESTORE_REGS    \
-    popl    %ebx;    \
-    popl    %edx;    \
-    popl    %ecx;    \
-    popl    %edi;    \
-    popl    %esi;    \
-    popl    %ebp;    \
-    popl    %eax;    \
+    popal;          \
     popl    %ds;    \
     popl    %es;    \
     popl    %fs;    \

diff --git a/kernel/interrupts.S b/kernel/interrupts.S
index bf3d0a761e7d651e39ac29c55a496ab190dcf145..13ddf46b3a5e3f53b4adcda9c82881f381de2838 100644 (file)
--- a/kernel/interrupts.S
+++ b/kernel/interrupts.S
@@ -66,11 +66,6 @@ DEF_IRQ(0,F)
 .extern irq_handler
 .extern    schedule
 _irq_handler:
-#if 1
-    /*
-     * 这些寄存器以及上面的中断号和中断自动压栈的寄存器
-     * 都存在中断栈中.
-     */
     SAVE_REGS
 
     movw    %ss,%ax
@@ -82,7 +77,7 @@ _irq_handler:
     movl    %esp, %eax
     call    irq_handler
 
-    call    schedule
+    # call    schedule
 
     # movl    current, %esp
         
@@ -91,38 +86,3 @@ _irq_handler:
     addl    $4,%esp    /* 跳过中断号. */
 
     iret
-#endif
-
-#if 0    /* 2010.02.22 */
-    /*
-     * 这些寄存器以及上面的中断号和中断自动压栈的寄存器
-     * 都存在中断栈中.
-     */
-    SAVE_REGS
-
-    movw    %ss,%ax
-    movw    %ax, %ds
-    movw    %ax, %es
-    movw    %ax, %fs
-    movw    %ax, %gs
-
-    movl    %esp, %eax
-    call    irq_handler
-
-
-    /* 向调度器传递栈帧的位置以便其保存现场. */
-    pushl    %esp
-    call    schedule
-
-    /*
-     * 利用task_struct 里的内容作为新进程的现场来恢复
-     * 所以用不着针对pushl %esp 写 addl $4,%esp了.
-     */
-    movl    current, %esp
-        
-    RESTORE_REGS
-    
-    addl    $4,%esp    /* 跳过中断号. */
-
-    iret
-#endif

diff --git a/kernel/syscall.S b/kernel/syscall.S
index da10d88fb716aa25e3cb8d41089b77ffe035c1bb..9e9bf741a5c2ce4206ea00f9ea4af045ffb7c049 100644 (file)
--- a/kernel/syscall.S
+++ b/kernel/syscall.S
@@ -7,10 +7,12 @@
  * 
  *      Author: Zhao Yanbai [zhaoyanbai@126.com]
  * 
- *     Version:    1.0
+ *     Version: 1.0
  * Create Date: Tue Feb 10 13:20:33 2009
  *     Version: 2.0
  * Last Update: Wed Feb 10 23:36:34 2010
+ *     Version: 3.0
+ * Last Update: Fri May  2 00:21:37 2014
  * 
  *--------------------------------------------------------------------------
  */
@@ -19,107 +21,51 @@
 #include <system.h>
 #include <syscall.h>
 
-#define TASK_SIZE 4096*2
 .code32
-#if 0
-.extern sysc_handler_table
-#endif
 .text
 .global syscall_entry
 .global ret_from_fork
 .global sysexit
 
-#if 1
+#define EAX 32
+
 syscall_entry:
     movl    (%esp),%esp
 
     SAVE_REGS
 
-    pushfl
-    pushl    %ebp
     pushl    %eax
-
     movw    %ss, %ax
     movw    %ax, %ds
     movw    %ax, %es
     movw    %ax, %gs
     movw    %ax, %fs
-
     popl    %eax
 
     cmpl    $SYSC_NUM, %eax
-    jae    bad_syscnr
+    jae     bad_sysc_nr
 
     call    *sysc_handler_table(,%eax,4)
 
-ret_from_bad_syscnr:
-    popl    %ebp
-    popfl
+syscall_exit:
+    movl    %eax, EAX(%esp)
+
     RESTORE_REGS
     
     leal    sysexit, %edx
     movl    %ebp, %ecx
 
-    sti        /* sysenter会自动清除IF.貌似sysexit不会自动置位 */
+    sti        /* sysenter have cleared IF, and sysexit will not set IF. */
     sysexit
 
-ret_from_fork: /* for compiler now */
-bad_syscnr:
+bad_sysc_nr:
     call    sysc_bad_syscnr
-    jmp    ret_from_bad_syscnr
-
-#else
-syscall_entry:
-    /* 此时%esp存的是current的地址(&current) */
-    movl    (%esp),%esp        /* 获得current的值 */
-    addl    $TASK_SIZE, %esp    /* 指向PCB的顶部 */
-
-    pushl    %ds            /* %ss */
-    pushl    %ebp            /* %esp */
-    pushfl                /* %eflags */
-    pushl    $SELECTOR_USER_CS    /* %cs */
-    pushl    %gs:(,%ebp)        /* %eip */
-    pushl    %eax            /* sysc_nr */
-    SAVE_REGS
-
-    pushl    %eax
-    movw    %ss,%ax
-    movw    %ax, %ds
-    movw    %ax, %es
-    movw    %ax, %gs
-    movw    %ax, %fs
-    popl    %eax
+    jmp     sysc_exit
 
-    cmpl    $SYSC_NUM, %eax
-    jae    bad_syscnr
-
-    call    *sysc_handler_table(,%eax,4)
-
-ret_from_bad_syscnr:
-
-
-    movl    %eax, 0x18(%esp)    /* return value */
-
-    /*
-     * fork 后的新进程的返回值已经在栈上被设定为0了.
-     * ret_from_fork 就是新进程被换入执行的入口地址.
-     */
-ret_from_fork:
-
-    RESTORE_REGS
+ret_from_fork: 
+    xorl    %eax, %eax
+    jmp     sysc_exit
     
-    movl    0x04(%esp), %edx    /* sysexit 参数 %eip */
-    movl    0x10(%esp), %ecx    /* sysexit 参数 %esp */
-
-    #xchg    %bx, %bx
-    sti        /* sysenter会自动清除IF.貌似sysexit不会自动置位 */
-    sysexit
-
-bad_syscnr:
-    call    sysc_bad_syscnr
-    jmp    ret_from_bad_syscnr
-#endif
-
 
 # this routine should be load align by PAGE_SIZE
 # this page is shared by the kernel and userspace