Eliminate annoying Pseudodesc structure.

Eliminate unnecessary parts of mmu.h.

diff --git a/mmu.h b/mmu.h
index b90a9e38635145eb98d239faa3b786d33a1e664f..829815d3778405992b5b0c96e2890bf0a9efe770 100644 (file)
--- a/mmu.h
+++ b/mmu.h
@@ -5,95 +5,10 @@
  */
 
 /*
- *
- *     Part 1.  Paging data structures and constants.
- *
+ *     Register flags and fundamental constants.
  */
 
-// A linear address 'la' has a three-part structure as follows:
-//
-// +--------10------+-------10-------+---------12----------+
-// | Page Directory |   Page Table   | Offset within Page  |
-// |      Index     |      Index     |                     |
-// +----------------+----------------+---------------------+
-//  \--- PDX(la) --/ \--- PTX(la) --/ \---- PGOFF(la) ----/
-//  \----------- PPN(la) -----------/
-//
-// The PDX, PTX, PGOFF, and PPN macros decompose linear addresses as shown.
-// To construct a linear address la from PDX(la), PTX(la), and PGOFF(la),
-// use PGADDR(PDX(la), PTX(la), PGOFF(la)).
-
-// page number field of address
-#define PPN(la)                (((uintptr_t) (la)) >> PTXSHIFT)
-#define VPN(la)                PPN(la)         // used to index into vpt[]
-
-// page directory index
-#define PDX(la)                ((((uintptr_t) (la)) >> PDXSHIFT) & 0x3FF)
-#define VPD(la)                PDX(la)         // used to index into vpd[]
-
-// page table index
-#define PTX(la)                ((((uintptr_t) (la)) >> PTXSHIFT) & 0x3FF)
-
-// offset in page
-#define PGOFF(la)      (((uintptr_t) (la)) & 0xFFF)
-
-// construct linear address from indexes and offset
-#define PGADDR(d, t, o)        ((void*) ((d) << PDXSHIFT | (t) << PTXSHIFT | (o)))
-
-// Page directory and page table constants.
-#define NPDENTRIES     1024            // page directory entries per page directory
-#define NPTENTRIES     1024            // page table entries per page table
-
 #define PGSIZE         4096            // bytes mapped by a page
-#define PGSHIFT                12              // log2(PGSIZE)
-
-#define PTSIZE         (PGSIZE*NPTENTRIES) // bytes mapped by a page directory entry
-#define PTSHIFT                22              // log2(PTSIZE)
-
-#define PTXSHIFT       12              // offset of PTX in a linear address
-#define PDXSHIFT       22              // offset of PDX in a linear address
-
-// Page table/directory entry flags.
-#define PTE_P          0x001   // Present
-#define PTE_W          0x002   // Writeable
-#define PTE_U          0x004   // User
-#define PTE_PWT                0x008   // Write-Through
-#define PTE_PCD                0x010   // Cache-Disable
-#define PTE_A          0x020   // Accessed
-#define PTE_D          0x040   // Dirty
-#define PTE_PS         0x080   // Page Size
-#define PTE_MBZ                0x180   // Bits must be zero
-
-// The PTE_AVAIL bits aren't used by the kernel or interpreted by the
-// hardware, so user processes are allowed to set them arbitrarily.
-#define PTE_AVAIL      0xE00   // Available for software use
-
-// Only flags in PTE_USER may be used in system calls.
-#define PTE_USER       (PTE_AVAIL | PTE_P | PTE_W | PTE_U)
-
-// address in page table entry
-#define PTE_ADDR(pte)  ((physaddr_t) (pte) & ~0xFFF)
-
-// Control Register flags
-#define CR0_PE         0x00000001      // Protection Enable
-#define CR0_MP         0x00000002      // Monitor coProcessor
-#define CR0_EM         0x00000004      // Emulation
-#define CR0_TS         0x00000008      // Task Switched
-#define CR0_ET         0x00000010      // Extension Type
-#define CR0_NE         0x00000020      // Numeric Errror
-#define CR0_WP         0x00010000      // Write Protect
-#define CR0_AM         0x00040000      // Alignment Mask
-#define CR0_NW         0x20000000      // Not Writethrough
-#define CR0_CD         0x40000000      // Cache Disable
-#define CR0_PG         0x80000000      // Paging
-
-#define CR4_PCE                0x00000100      // Performance counter enable
-#define CR4_MCE                0x00000040      // Machine Check Enable
-#define CR4_PSE                0x00000010      // Page Size Extensions
-#define CR4_DE         0x00000008      // Debugging Extensions
-#define CR4_TSD                0x00000004      // Time Stamp Disable
-#define CR4_PVI                0x00000002      // Protected-Mode Virtual Interrupts
-#define CR4_VME                0x00000001      // V86 Mode Extensions
 
 // Eflags register
 #define FL_CF          0x00000001      // Carry Flag
@@ -123,10 +38,9 @@
 #define FEC_WR         0x2     // Page fault caused by a write
 #define FEC_U          0x4     // Page fault occured while in user mode
 
-
 /*
  *
- *     Part 2.  Segmentation data structures and constants.
+ *     Segmentation data structures and constants.
  *
  */
 
@@ -202,7 +116,7 @@ struct Segdesc {
 
 /*
  *
- *     Part 3.  Traps.
+ *     Traps.
  *
  */
 
@@ -296,13 +210,5 @@ struct Gatedesc {
        (gate).off_31_16 = (uint32_t) (off) >> 16;              \
 }
 
-// Pseudo-descriptors used for LGDT, LLDT and LIDT instructions.
-struct Pseudodesc {
-       uint16_t _garbage;         // LGDT supposed to be from address 4N+2
-       uint16_t lim;              // Limit
-       uint32_t base __attribute__ ((packed));       // Base address
-};
-#define PD_ADDR(desc)  (&(desc).pd_lim)
-
 #endif /* !__ASSEMBLER__ */
 

diff --git a/proc.c b/proc.c
index f24f4f86d5a92e24bca45ece30ea31b4418ff115..4bcd4ab2ccaad6ab9aa41d0fc642f9f6fafa46ff 100644 (file)
--- a/proc.c
+++ b/proc.c
@@ -38,9 +38,6 @@ setupsegs(struct proc *p)
   p->gdt[SEG_TSS].s = 0;
   p->gdt[SEG_UCODE] = SEG(STA_X|STA_R, (unsigned)p->mem, p->sz, 3);
   p->gdt[SEG_UDATA] = SEG(STA_W, (unsigned)p->mem, p->sz, 3);
-  p->gdt_pd._garbage = 0;
-  p->gdt_pd.lim = sizeof(p->gdt) - 1;
-  p->gdt_pd.base = (unsigned) p->gdt;
 }
 
 // Look in the process table for an UNUSED proc.
@@ -159,7 +156,9 @@ scheduler(void)
       // to confine all the inline assembly.
       // XXX probably ought to lgdt on trap return too, in case
       // a system call has moved a program or changed its size.
-      asm volatile("lgdt %0" : : "g" (p->gdt_pd.lim));
+      lgdt(p->gdt, sizeof p->gdt);
+    // asm volatile("lgdt %0" : : "g" (p->gdt_pd.lim));
+
       ltr(SEG_TSS << 3);
 
       // Switch to chosen process.  It is the process's job 

diff --git a/proc.h b/proc.h
index 72bdcf3d42650c63f1a29f6a4142fd6a922df5f9..9353f880cccc30d732ebc4620ccecf831690587b 100644 (file)
--- a/proc.h
+++ b/proc.h
@@ -50,7 +50,6 @@ struct proc{
 
   struct Taskstate ts;  // only to give cpu address of kernel stack
   struct Segdesc gdt[NSEGS];
-  struct Pseudodesc gdt_pd;
   unsigned esp; // kernel stack pointer
   unsigned ebp; // kernel frame pointer
 

diff --git a/trap.c b/trap.c
index 74ea864d9a9ac82a9a8ef37638f107b801c0f622..85d8eef0c8aaf064de8208d3cc81343f4231b1a9 100644 (file)
--- a/trap.c
+++ b/trap.c
@@ -8,7 +8,6 @@
 #include "syscall.h"
 
 struct Gatedesc idt[256];
-struct Pseudodesc idt_pd = { 0, sizeof(idt) - 1, (unsigned) &idt };
 extern unsigned vectors[]; /* vectors.S, array of 256 entry point addresses */
 
 extern void trapenter();
@@ -28,7 +27,7 @@ tvinit()
 void
 idtinit()
 {
-  asm volatile("lidt %0" : : "g" (idt_pd.lim));
+  lidt(idt, sizeof idt);
 }
 
 void

diff --git a/types.h b/types.h
index 01989d6ccd864a572dcca9a50218eb2d90c2d666..f520c975312a0b2c312313d6ab74646a936ee77d 100644 (file)
--- a/types.h
+++ b/types.h
@@ -4,3 +4,4 @@ typedef unsigned short uint16_t;
 typedef unsigned char uint8_t;
 typedef uint32_t uintptr_t;
 typedef uint32_t physaddr_t;
+typedef unsigned int uint;

diff --git a/x86.h b/x86.h
index 6c67df7091c8cf97149a6ddd3e46ff52578ecee2..a25d8759180eeb109873f5131b8380dd7c96e314 100644 (file)
--- a/x86.h
+++ b/x86.h
@@ -12,7 +12,10 @@ static __inline void outsw(int port, const void *addr, int cnt) __attribute__((a
 static __inline void outsl(int port, const void *addr, int cnt) __attribute__((always_inline));
 static __inline void outl(int port, uint32_t data) __attribute__((always_inline));
 static __inline void invlpg(void *addr) __attribute__((always_inline));
-static __inline void lidt(void *p) __attribute__((always_inline));
+struct Segdesc;
+static __inline void lgdt(struct Segdesc *p, int) __attribute__((always_inline));
+struct Gatedesc;
+static __inline void lidt(struct Gatedesc *p, int) __attribute__((always_inline));
 static __inline void lldt(uint16_t sel) __attribute__((always_inline));
 static __inline void ltr(uint16_t sel) __attribute__((always_inline));
 static __inline void lcr0(uint32_t val) __attribute__((always_inline));
@@ -141,9 +144,27 @@ invlpg(void *addr)
 }  
 
 static __inline void
-lidt(void *p)
+lgdt(struct Segdesc *p, int size)
 {
-       __asm __volatile("lidt (%0)" : : "r" (p));
+       volatile uint16_t pd[3];
+  
+       pd[0] = size-1;
+       pd[1] = (uint)p;
+       pd[2] = (uint)p >> 16;
+
+       asm volatile("lgdt (%0)" : : "g" (pd));
+}
+
+static __inline void
+lidt(struct Gatedesc *p, int size)
+{
+       volatile uint16_t pd[3];
+  
+       pd[0] = size-1;
+       pd[1] = (uint)p;
+       pd[2] = (uint)p >> 16;
+  
+       asm volatile("lidt (%0)" : : "g" (pd));
 }
 
 static __inline void