TempleOSCDV4.03.ISO

Demo/Lectures/Mem/Mem2Meg.CPP

@@ -0,0 +1,202 @@
+//This file is required by $LK,"::/Demo/Lectures/Mem/Uncached.CPP"$.
+
+U8 *Mem2MegAlloc(I64 *_pages2Meg,CBlkPool *bp=NULL)
+{/*Alloc 2Meg pages from BlkPool. Don't link to task.
+(Linking to a task means they will be freed when the task dies.)
+It might give you more than you asked for
+so a ptr to a page count is passed.
+
+Return: NULL if out of memory.
+*/
+  I64 i,j,*pte,num=*_pages2Meg;
+  CMemBlk *result=NULL,*m,*m1;
+
+  if (!bp) bp=sys_code_bp;
+  PUSHFD
+  CLI
+  while (LBts(&bp->locked_flags,BPlf_LOCKED))
+    PAUSE
+  num<<=21-MEM_PAGE_BITS;
+
+  m=&bp->mem_free_2meg_lst;
+  while (TRUE) {
+    if (!(result=m->next))
+      break;
+    if (result->pages<num)
+      m=result;
+    else {
+      if (result->pages==num) {
+	m->next=result->next;
+	goto am_done;
+      } else {
+	result->pages-=num;
+	result(U8 *)+=result->pages<<MEM_PAGE_BITS;
+	result->pages=num;
+	goto am_done;
+      }
+    }
+  }
+
+  m=&bp->mem_free_lst;
+  while (TRUE) {
+    if (!(result=m->next)) {
+      num=0;
+      result=NULL; //Out of memory
+      goto am_done;
+    }
+    if (result->pages<num)
+      m=result;
+    else {
+      if (result->pages==num) {
+	if (result(U8 *)&0x1FFFFF)
+	  m=result;
+	else {
+	  m->next=result->next;
+	  goto am_done;
+	}
+      } else {
+	if (i=(result(U8 *)&0x1FFFFF)>>MEM_PAGE_BITS) {
+	  j=1<<(21-MEM_PAGE_BITS)-i;
+	  if (result->pages<num+j)
+	    m=result;
+	  else if (result->pages==num+j) {
+	    result->pages-=num;
+	    result(U8 *)+=result->pages<<MEM_PAGE_BITS;
+	    result->pages=num;
+	    goto am_done;
+	  } else {
+	    m1=result;
+	    result(U8 *)+=j<<MEM_PAGE_BITS;
+	    result->pages=num;
+	    m=result(U8 *)+num<<MEM_PAGE_BITS;
+	    m->pages=m1->pages-num-j;
+	    m1->pages=j;
+	    m->next=m1->next;
+	    m1->next=m;
+	    m->mb_signature=MBS_UNUSED_SIGNATURE_VAL;
+	    goto am_done;
+	  }
+	} else {
+	  m=m->next=result(U8 *)+num<<MEM_PAGE_BITS;
+	  m->next=result->next;
+	  m->pages=result->pages-num;
+	  m->mb_signature=MBS_UNUSED_SIGNATURE_VAL;
+	  result->pages=num;
+	  goto am_done;
+	}
+      }
+    }
+  }
+am_done:
+  i=num<<MEM_PAGE_BITS;
+  bp->used_u8s+=i;
+  num>>=21-MEM_PAGE_BITS;
+  *_pages2Meg=num;
+  m=result;
+  m1=m(U8 *)+i;
+  while (m<m1) {
+    pte=MemPageTable(m);
+    *pte &= ~0x18;
+    InvlPg(m);
+    m(U8 *)+=MemPageSize(m);
+  }
+  LBtr(&bp->locked_flags,BPlf_LOCKED);
+  POPFD
+  return result;
+}
+
+U8 *Mem2MegUncachedAlloc(I64 *_pages2Meg,CBlkPool *bp=NULL)
+{/*Alloc 2Meg pages from BlkPool. Don't link to task.
+(Linking to a task means they will be freed when the task dies.)
+It will be marked uncached. It might give you more than you asked for
+so a ptr to a page count is passed.
+
+Return: NULL if out of memory.
+*/
+  CMemBlk *result,*m,*m1;
+  I64 num=*_pages2Meg,*pte;
+  if (result=Mem2MegAlloc(_pages2Meg,bp)) {
+    num=*_pages2Meg;
+    m=result;
+    m1=m(U8 *)+num<<21;
+    while (m<m1) {
+      pte=MemPageTable(m);
+      *pte= *pte& ~0x18 |0x10;
+      InvlPg(m);
+      m(U8 *)+=MemPageSize(m);
+    }
+  }
+  return result;
+}
+
+U8 *Mem2MegWriteThruAlloc(I64 *_pages2Meg,CBlkPool *bp=NULL)
+{/*Alloc 2Meg pages from BlkPool. Don't link to task.
+(Linking to a task means they will be freed when the task dies.)
+It will be marked write-through. It might give you more than you asked for
+so a ptr to a page count is passed.
+
+Return: NULL if out of memory.
+*/
+  CMemBlk *result,*m,*m1;
+  I64 num=*_pages2Meg,*pte;
+  if (result=Mem2MegAlloc(_pages2Meg,bp)) {
+    num=*_pages2Meg;
+    m=result;
+    m1=m(U8 *)+num<<21;
+    while (m<m1) {
+      pte=MemPageTable(m);
+      *pte= *pte& ~0x18 |8;
+      InvlPg(m);
+      m(U8 *)+=MemPageSize(m);
+    }
+  }
+  return result;
+}
+
+U0 Mem2MegFree(CMemBlk *m,I64 pages2Meg,CBlkPool *bp=NULL)
+{//Return non-task 2Meg pages to BlkPool.
+  I64 *pte;
+  CMemBlk *m1,*m2;
+  if (m) {
+    if (!bp) bp=sys_code_bp;
+    m2=m;
+    m1=m(U8 *)+pages2Meg<<21;
+    while (m2<m1) {
+      pte=MemPageTable(m2);
+      *pte=*pte & ~0x18;
+      InvlPg(m2);
+      m2(U8 *)+=MemPageSize(m2);
+    }
+    PUSHFD
+    CLI
+    while (LBts(&bp->locked_flags,BPlf_LOCKED))
+      PAUSE
+    m->mb_signature=MBS_UNUSED_SIGNATURE_VAL;
+    m->pages=pages2Meg<<(21-MEM_PAGE_BITS);
+    bp->used_u8s-=pages2Meg<<21;
+    m->next=bp->mem_free_2meg_lst;
+    bp->mem_free_2meg_lst=m;
+    LBtr(&bp->locked_flags,BPlf_LOCKED);
+    POPFD
+  }
+}
+
+CHeapCtrl *HeapCtrlBPInit(CBlkPool *bp,I64 pages512)
+{//Make mem chunk into HeapCtrl and BlkPool.
+  I64 num;
+  CMemBlk *m;
+  CHeapCtrl *hc;
+  MemSet(bp,0,sizeof(CBlkPool)+sizeof(CHeapCtrl));
+  hc=HeapCtrlInit(bp(U8 *)+sizeof(CBlkPool),,bp);
+  m=(bp(U8 *)+sizeof(CBlkPool)+sizeof(CHeapCtrl)+MEM_PAGE_SIZE-1)&
+	~(MEM_PAGE_SIZE-1);
+  num=(bp(U8 *)+pages512<<MEM_PAGE_BITS-m(U8 *))>>MEM_PAGE_BITS;
+  bp->alloced_u8s=(pages512-num)<<MEM_PAGE_BITS;
+  BlkPoolAdd(bp,m,num);
+  return hc;
+}
+
+/*  PCI hardware devices, when they require uncached memory buffers, need
+this code.  TempleOS, however, has a law requiring only IN/OUT port hardware
+access except VGA, handled here: $LK,"::/Kernel/Mem/PageTables.CPP"$.
+*/

Demo/Lectures/Mem/PageTableEntries1.CPP

@@ -0,0 +1,47 @@
+/*What's funner than page tables for programmers to play with!!
+
+This changes a page table entry for VGA graphics memory.
+TempleOS keeps a cached copy of VGA memory in
+$LK,"gr.screen_image",A="MN:CGrGlbls"$.  See $LK,"GrUpdateVGAGraphics",A="MN:GrUpdateVGAGraphics"$.
+
+TempleOS used 4096 size pages for memory below addr 2 Meg
+and 2 Meg pages above two Meg.  See $LK,"MemPageSize",A="MN:MemPageSize"$() and $LK,"INIT_MEMORY",A="FF:::/Kernel/Mem/PageTables.CPP,SYS_INIT_MEM"$.
+*/
+
+U0 PageTableDemo1()
+{
+  I64 *pte=MemPageTable(VGAM_GRAPHICS),p0,p1;
+  "Page table entries for VGA screen memory\n";
+  DocD(pte);
+  PressAKey;
+
+  p0=pte[0];
+  p1=pte[1];
+  pte[0]=p1;
+  pte[1]=p0;
+  InvlPg(VGAM_GRAPHICS); //Invalidate translation look aside buffer (TLB).
+  InvlPg(VGAM_GRAPHICS+0x1000);
+
+  //Use this if you wish to change
+  //the page table reg.
+
+  //  SetRAX(0x100000+0x1000*(MEM_NUM_PML1+MEM_NUM_PML2+MEM_NUM_PML3));
+  //  MOV_CR3_EAX
+
+  //<CTRL-ALT-v> will flush screen VGA cache.
+  VGAFlush;
+  PressAKey;
+
+  pte[0]=p0;
+  pte[1]=p1;
+  InvlPg(VGAM_GRAPHICS);
+  InvlPg(VGAM_GRAPHICS+0x1000);
+
+  //<CTRL-ALT-v> will flush screen VGA cache.
+  VGAFlush;
+}
+
+PageTableDemo1;
+
+//See $LK,"CBlkPool",A="MN:CBlkPool"$, $LK,"CHeapCtrl",A="MN:CHeapCtrl"$, $LK,"sys_code_bp",A="MN:sys_code_bp"$ and $LK,"sys_data_bp",A="MN:sys_data_bp"$.
+//See $LK,"Memory Overview",A="FI:::/Doc/MemOverview.TXT"$ and $LK,"Memory Routines",A="HI:Memory"$.

Demo/Lectures/Mem/PageTableEntries2.CPP

@@ -0,0 +1,37 @@
+I64 *addr=VGAM_GRAPHICS,
+   *pte_addr=MemPageTable(addr),
+   err_code=0,
+   *reported_fault_addr;
+/*
+  0[RBP]=old base ptr
+  8[RBP]=err code
+  16[RBP]=RIP
+  24[RBP]=RIP_SELECTOR
+  32[RBP]=RFLAGS
+  40[RBP]=RSP
+  48[RBP]=STK_SELECTOR
+*/
+
+interrupt haserrcode U0 IntPageFault()
+{
+  I64 reg *rbp=GetRBP;
+  *pte_addr|=1;
+  InvlPg(addr);
+  err_code=rbp[1];
+  MOV_RAX_CR2
+  reported_fault_addr=GetRAX;
+}
+
+U0 PageTableDemo2()
+{
+  U8 *old_idte=IntEntrySet(I_PAGE_FAULT,&IntPageFault,IDTET_IRQ);
+  err_code=0;
+  *pte_addr &=~1; //Not present
+  InvlPg(addr);
+  WinMgrSync; //wait for VGA update
+  WinMgrSync;
+  IntEntrySet(I_PAGE_FAULT,old_idte,IDTET_IRQ);
+  "Err Code:%X Addr:%X\n",err_code,reported_fault_addr;
+}
+
+PageTableDemo2;

Demo/Lectures/Mem/Uncached.CPP

@@ -0,0 +1,46 @@
+// Requires $LK,"::/Demo/Lectures/Mem/Mem2Meg.CPP"$.
+
+Cd(__DIR__);;
+#include "Mem2Meg"
+
+#define SAMPLE_SIZE	100000
+U0 TimeIns()
+{
+  I64 i,start,end;
+  I64 *cached_I64=MAlloc(sizeof(I64)),
+	shared_blks,*uncached_I64;
+  CBlkPool *bp;
+  CHeapCtrl *hc;
+
+  "$$RED$$Now, this demo seems broken, perhaps,\n"
+	"because I run in a virtual machine.$$FG$$\n\n";
+  CPURep;
+
+  shared_blks=1;
+  bp=Mem2MegUncachedAlloc(&shared_blks);
+  hc=HeapCtrlBPInit(bp,shared_blks<<12);
+  uncached_I64=MAlloc(sizeof(I64),hc);
+
+  //Measure cached time
+  start=GetTSC;
+  for (i=0;i<SAMPLE_SIZE;i++)
+    *cached_I64=i;
+
+  end=GetTSC;
+  "  Cached Cycles: %10,d\n",end-start;
+
+  //Measure uncached time
+  start=GetTSC;
+  for (i=0;i<SAMPLE_SIZE;i++)
+    *uncached_I64=i;
+  end=GetTSC;
+  "Uncached Cycles: %10,d\n",end-start;
+
+  "$$GREEN$$The difference is even greater\n"
+	"because the loop overhead was not subtracted.$$FG$$\n\n";
+  Free(cached_I64);
+  Free(uncached_I64);
+  Mem2MegFree(bp,shared_blks);
+}
+
+TimeIns;