1 files changed, 67 insertions, 0 deletions

diff --git a/src/include/asm/system.h b/src/include/asm/system.h
new file mode 100644
index 0000000..9bc027a
--- /dev/null
+++ b/src/include/asm/system.h
@@ -0,0 +1,67 @@
+#define move_to_user_mode() \
+__asm__ ("movl %%esp,%%eax\n\t" \
+        "pushl $0x17\n\t" \
+        "pushl %%eax\n\t" \
+        "pushfl\n\t" \
+        "pushl $0x0f\n\t" \
+        "pushl $1f\n\t" \
+        "iret\n" \
+        "1:\tmovl $0x17,%%eax\n\t" \
+        "movw %%ax,%%ds\n\t" \
+        "movw %%ax,%%es\n\t" \
+        "movw %%ax,%%fs\n\t" \
+        "movw %%ax,%%gs" \
+        :::"ax")
+
+#define sti() __asm__ ("sti"::)
+#define cli() __asm__ ("cli"::)
+#define nop() __asm__ ("nop"::)
+
+#define iret() __asm__ ("iret"::)
+
+#define _set_gate(gate_addr,type,dpl,addr) \
+__asm__ ("movw %%dx,%%ax\n\t" \
+        "movw %0,%%dx\n\t" \
+        "movl %%eax,%1\n\t" \
+        "movl %%edx,%2" \
+        : \
+        : "i" ((short) (0x8000+(dpl<<13)+(type<<8))), \
+        "o" (*((char *) (gate_addr))), \
+        "o" (*(4+(char *) (gate_addr))), \
+        "d" ((char *) (addr)),"a" (0x00080000))
+
+#define set_intr_gate(n,addr) \
+        _set_gate(&idt[n],14,0,addr)
+
+#define set_trap_gate(n,addr) \
+        _set_gate(&idt[n],15,0,addr)
+
+#define set_system_gate(n,addr) \
+        _set_gate(&idt[n],15,3,addr)
+
+#define _set_seg_desc(gate_addr,type,dpl,base,limit) {\
+        *(gate_addr) = ((base) & 0xff000000) | \
+                (((base) & 0x00ff0000)>>16) | \
+                ((limit) & 0xf0000) | \
+                ((dpl)<<13) | \
+                (0x00408000) | \
+                ((type)<<8); \
+        *((gate_addr)+1) = (((base) & 0x0000ffff)<<16) | \
+                ((limit) & 0x0ffff); }
+
+#define _set_tssldt_desc(n,addr,type) \
+__asm__ ("movw $104,%1\n\t" \
+        "movw %%ax,%2\n\t" \
+        "rorl $16,%%eax\n\t" \
+        "movb %%al,%3\n\t" \
+        "movb $" type ",%4\n\t" \
+        "movb $0x00,%5\n\t" \
+        "movb %%ah,%6\n\t" \
+        "rorl $16,%%eax" \
+        ::"a" (addr), "m" (*(n)), "m" (*(n+2)), "m" (*(n+4)), \
+         "m" (*(n+5)), "m" (*(n+6)), "m" (*(n+7)) \
+        )
+
+#define set_tss_desc(n,addr) _set_tssldt_desc(((char *) (n)),((int)(addr)),"0x89")
+#define set_ldt_desc(n,addr) _set_tssldt_desc(((char *) (n)),((int)(addr)),"0x82")
+