Avoid "boot" in xv6

Makefile

@@ -110,7 +110,7 @@ initcode: initcode.S
 	$(OBJDUMP) -S initcode.o > initcode.asm
 
 kernel: $(OBJS) entry.o data.o entryother initcode
-	$(LD) $(LDFLAGS) -T kernel.ld -e multiboot_entry -o kernel entry.o data.o $(OBJS) -b binary initcode entryother
+	$(LD) $(LDFLAGS) -T kernel.ld -e entry -o kernel entry.o data.o $(OBJS) -b binary initcode entryother
 	$(OBJDUMP) -S kernel > kernel.asm
 	$(OBJDUMP) -t kernel | sed '1,/SYMBOL TABLE/d; s/ .* / /; /^$$/d' > kernel.sym
 

defs.h

@@ -62,7 +62,7 @@ extern uchar    ioapicid;
 void            ioapicinit(void);
 
 // kalloc.c
-char*           boot_alloc(void);
+char*           enter_alloc(void);
 char*           kalloc(void);
 void            kfree(char*);
 void            kinit(void);

entry.S

@@ -34,17 +34,17 @@ multiboot_header:
   .long multiboot_header
   .long edata
   .long end
-  .long multiboot_entry
+  .long entry
 
-# Multiboot entry point.  Machine is mostly set up.
+# Entering xv6 on boot processor.  Machine is mostly set up.
-.globl multiboot_entry
+.globl entry
-multiboot_entry:
+entry:
   # Turn on page size extension for 4Mbyte pages
   movl    %cr4, %eax
   orl     $(CR4_PSE), %eax
   movl    %eax, %cr4
   # Set page directory
-  movl    $(V2P_WO(bootpgdir)), %eax
+  movl    $(V2P_WO(enterpgdir)), %eax
   movl    %eax, %cr3
   # Turn on paging.
   movl    %cr0, %eax

entryother.S

@@ -14,8 +14,8 @@
 # Bootothers (in main.c) sends the STARTUPs one at a time.
 # It copies this code (start) at 0x7000.
 # It puts the address of a newly allocated per-core stack in start-4,
-# the address of the place to jump to (mpboot) in start-8, and the physical
+# the address of the place to jump to (mpenter) in start-8, and the physical
-# address of bootpgdir in start-12.
+# address of enterpgdir in start-12.
 #
 #
 # This code is identical to bootasm.S except:
@@ -54,7 +54,7 @@ start32:
   movl    %cr4, %eax
   orl     $(CR4_PSE), %eax
   movl    %eax, %cr4
-  # Use bootpgdir as our initial page table
+  # Use enterpgdir as our initial page table
   movl    (start-12), %eax
   movl    %eax, %cr3
   # Turn on paging.
@@ -62,9 +62,9 @@ start32:
   orl     $(CR0_PE|CR0_PG|CR0_WP), %eax
   movl    %eax, %cr0
 
-  # Switch to the stack allocated by enterothers()
+  # Switch to the stack allocated by startothers()
   movl    (start-4), %esp
-  # Call mpboot()
+  # Call mpenter()
   call	 *(start-8)
 
   movw    $0x8a00, %ax

kalloc.c

@@ -21,15 +21,15 @@ struct {
 extern char end[]; // first address after kernel loaded from ELF file
 char *newend;
 
-// simple page allocator to get off the ground during boot
+// simple page allocator to get off the ground during entry
 char *
-boot_alloc(void)
+enter_alloc(void)
 {
   if (newend == 0)
     newend = end;
 
   if ((uint) newend >= KERNBASE + 0x400000)
-    panic("only first 4Mbyte are mapped during boot");
+    panic("only first 4Mbyte are mapped during entry");
   void *p = (void*)PGROUNDUP((uint)newend);
   memset(p, 0, PGSIZE);
   newend = newend + PGSIZE;

lapic.c

@@ -132,7 +132,7 @@ microdelay(int us)
 
 #define IO_RTC  0x70
 
-// Start additional processor running bootstrap code at addr.
+// Start additional processor running entry code at addr.
 // See Appendix B of MultiProcessor Specification.
 void
 
@@ -158,7 +158,7 @@ lapicstartap(uchar apicid, uint addr)
   lapicw(ICRLO, INIT | LEVEL);
   microdelay(100);    // should be 10ms, but too slow in Bochs!
   
-  // Send startup IPI (twice!) to enter bootstrap code.
+  // Send startup IPI (twice!) to enter code.
   // Regular hardware is supposed to only accept a STARTUP
   // when it is in the halted state due to an INIT.  So the second
   // should be ignored, but it is part of the official Intel algorithm.

main.c

@@ -6,7 +6,7 @@
 #include "proc.h"
 #include "x86.h"
 
-static void enterothers(void);
+static void startothers(void);
 static void mpmain(void)  __attribute__((noreturn));
 extern pde_t *kpgdir;
 
@@ -33,7 +33,7 @@ main(void)
   ideinit();       // disk
   if(!ismp)
     timerinit();   // uniprocessor timer
-  enterothers();    // start other processors (must come before kinit; must use boot_alloc)
+  startothers();    // start other processors (must come before kinit; must use enter_alloc)
   kinit();         // initialize memory allocator
   userinit();      // first user process  (must come after kinit)
   // Finish setting up this processor in mpmain.
@@ -42,7 +42,7 @@ main(void)
 
 // Other CPUs jump here from entryother.S.
 static void
-mpboot(void)
+mpenter(void)
 {
   switchkvm(); 
   seginit();
@@ -56,22 +56,22 @@ mpmain(void)
 {
   cprintf("cpu%d: starting\n", cpu->id);
   idtinit();       // load idt register
-  xchg(&cpu->booted, 1); // tell enterothers() we're up
+  xchg(&cpu->started, 1); // tell startothers() we're up
   scheduler();     // start running processes
 }
 
-pde_t bootpgdir[];
+pde_t enterpgdir[];
 
-// Start the non-boot processors.
+// Start the non-boot (AP) processors.
 static void
-enterothers(void)
+startothers(void)
 {
   extern uchar _binary_entryother_start[], _binary_entryother_size[];
   uchar *code;
   struct cpu *c;
   char *stack;
 
-  // Write bootstrap code to unused memory at 0x7000.
+  // Write entry code to unused memory at 0x7000.
   // The linker has placed the image of entryother.S in
   // _binary_entryother_start.
   code = p2v(0x7000);
@@ -81,44 +81,36 @@ enterothers(void)
     if(c == cpus+cpunum())  // We've started already.
       continue;
 
-    // Tell entryother.S what stack to use, the address of mpboot and pgdir;
+    // Tell entryother.S what stack to use, the address of mpenter and pgdir;
     // We cannot use kpgdir yet, because the AP processor is running in low 
-    // memory, so we use bootpgdir for the APs too.  kalloc can return addresses
+    // memory, so we use enterpgdir for the APs too.  kalloc can return addresses
     // above 4Mbyte (the machine may have much more physical memory than 4Mbyte), which 
-    // aren't mapped by bootpgdir, so we must allocate a stack using boot_alloc();
+    // aren't mapped by enterpgdir, so we must allocate a stack using enter_alloc();
     // This introduces the constraint that xv6 cannot use kalloc until after these 
-    // last boot_alloc invocations.
+    // last enter_alloc invocations.
-    stack = boot_alloc();
+    stack = enter_alloc();
     *(void**)(code-4) = stack + KSTACKSIZE;
-    *(void**)(code-8) = mpboot;
+    *(void**)(code-8) = mpenter;
-    *(int**)(code-12) = (void *) v2p(bootpgdir);
+    *(int**)(code-12) = (void *) v2p(enterpgdir);
 
     lapicstartap(c->id, v2p(code));
 
     // wait for cpu to finish mpmain()
-    while(c->booted == 0)
+    while(c->started == 0)
       ;
   }
 }
 
-// Boot page table used in multiboot.S and entryother.S.
+// Boot page table used in entry.S and entryother.S.
 // Page directories (and page tables), must start on a page boundary,
-// hence the "__aligned__" attribute.  Also, because of restrictions
+// hence the "__aligned__" attribute.  
-// related to linking and static initializers, we use "x + PTE_P"
-// here, rather than the more standard "x | PTE_P".  Everywhere else
-// you should use "|" to combine flags.
 // Use PTE_PS in page directory entry to enable 4Mbyte pages.
-pte_t dev_pgtable[NPTENTRIES];
-pte_t entry_pgtable[NPTENTRIES];
-
 __attribute__((__aligned__(PGSIZE)))
-pde_t bootpgdir[NPDENTRIES] = {
+pde_t enterpgdir[NPDENTRIES] = {
 	// Map VA's [0, 4MB) to PA's [0, 4MB)
-	[0]
+	[0] = (0) + PTE_P + PTE_W + PTE_PS,
-		= (0) + PTE_P + PTE_W + PTE_PS,
 	// Map VA's [KERNBASE, KERNBASE+4MB) to PA's [0, 4MB)
-	[KERNBASE>>PDXSHIFT]
+	[KERNBASE>>PDXSHIFT] = (0) + PTE_P + PTE_W + PTE_PS,
-    	        = (0) + PTE_P + PTE_W + PTE_PS,
 };
 
 //PAGEBREAK!

mp.c

@@ -1,4 +1,4 @@
-// Multiprocessor bootstrap.
+// Multiprocessor support
 // Search memory for MP description structures.
 // http://developer.intel.com/design/pentium/datashts/24201606.pdf
 

proc.h

@@ -7,7 +7,7 @@ struct cpu {
   struct context *scheduler;   // swtch() here to enter scheduler
   struct taskstate ts;         // Used by x86 to find stack for interrupt
   struct segdesc gdt[NSEGS];   // x86 global descriptor table
-  volatile uint booted;        // Has the CPU started?
+  volatile uint started;        // Has the CPU started?
   int ncli;                    // Depth of pushcli nesting.
   int intena;                  // Were interrupts enabled before pushcli?
   

sysproc.c

@@ -77,7 +77,7 @@ sys_sleep(void)
 }
 
 // return how many clock tick interrupts have occurred
-// since boot.
+// since start.
 int
 sys_uptime(void)
 {

vm.c

@@ -12,7 +12,7 @@ pde_t *kpgdir;  // for use in scheduler()
 struct segdesc gdt[NSEGS];
 
 // Set up CPU's kernel segment descriptors.
-// Run once at boot time on each CPU.
+// Run once on entry on each CPU.
 void
 seginit(void)
 {
@@ -146,7 +146,7 @@ setupkvm(char* (*alloc)(void))
 void
 kvmalloc(void)
 {
-  kpgdir = setupkvm(boot_alloc);
+  kpgdir = setupkvm(enter_alloc);
   switchkvm();
 }