X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?p=pintos-anon;a=blobdiff_plain;f=src%2Fuserprog%2Fgdt.c;h=e866037e2a24dc412da2f2068d4fe69476260756;hp=e3e1ddea4a3e82baa10cbc318230fc6c2d380fac;hb=e587ab7ffa2d548029189e540d5716f880932cb1;hpb=6c5c6fdfe80bad40c90c19b67f00226610d59a38

diff --git a/src/userprog/gdt.c b/src/userprog/gdt.c
index e3e1dde..e866037 100644
--- a/src/userprog/gdt.c
+++ b/src/userprog/gdt.c
@@ -1,8 +1,8 @@
-#include "gdt.h"
-#include "debug.h"
-#include "mmu.h"
-#include "palloc.h"
-#include "tss.h"
+#include "userprog/gdt.h"
+#include <debug.h>
+#include "userprog/tss.h"
+#include "threads/palloc.h"
+#include "threads/vaddr.h"
 
 /* The Global Descriptor Table (GDT).
 
@@ -20,7 +20,8 @@
    stack switching on interrupts.
 
    For more information on the GDT as used here, refer to
-   [IA32-v3] sections 3.2 through 3.5. */
+   [IA32-v3a] 3.2 "Using Segments" through 3.5 "System Descriptor
+   Types". */
 static uint64_t gdt[SEL_CNT];
 
 /* GDT helpers. */
@@ -44,10 +45,12 @@ gdt_init (void)
   gdt[SEL_UDSEG / sizeof *gdt] = make_data_desc (3);
   gdt[SEL_TSS / sizeof *gdt] = make_tss_desc (tss_get ());
 
-  /* Load GDTR, TR. */
+  /* Load GDTR, TR.  See [IA32-v3a] 2.4.1 "Global Descriptor
+     Table Register (GDTR)", 2.4.4 "Task Register (TR)", and
+     6.2.4 "Task Register".  */
   gdtr_operand = make_gdtr_operand (sizeof gdt - 1, gdt);
-  asm volatile ("lgdt %0" :: "m" (gdtr_operand));
-  asm volatile ("ltr %w0" :: "r" (SEL_TSS));
+  asm volatile ("lgdt %0" : : "m" (gdtr_operand));
+  asm volatile ("ltr %w0" : : "q" (SEL_TSS));
 }
 
 /* System segment or code/data segment? */
@@ -74,7 +77,7 @@ enum seg_granularity
    it can be used in rings numbered DPL or lower.  In practice,
    DPL==3 means that user processes can use the segment and
    DPL==0 means that only the kernel can use the segment.  See
-   [IA32-v3] section 4.5 for further discussion. */
+   [IA32-v3a] 4.5 "Privilege Levels" for further discussion. */
 static uint64_t
 make_seg_desc (uint32_t base,
                uint32_t limit,
@@ -125,7 +128,8 @@ make_data_desc (int dpl)
 
 /* Returns a descriptor for an "available" 32-bit Task-State
    Segment with its base at the given linear address, a limit of
-   0x67 bytes (the size of a 32-bit TSS), and a DPL of 0. */
+   0x67 bytes (the size of a 32-bit TSS), and a DPL of 0.
+   See [IA32-v3a] 6.2.2 "TSS Descriptor". */
 static uint64_t
 make_tss_desc (void *laddr)
 {