Make improvements

- Emulator can now test the αcτµαlly pδrταblε εxεcµταblε bootloader

- Whipped up a webserver named redbean. It services 150k requests per
  second on a single core. Bundling assets inside zip enables extremely
  fast serving for two reasons. The first is that zip central directory
  lookups go faster than stat() system calls. The second is that both
  zip and gzip content-encoding use DEFLATE, therefore, compressed
  responses can be served via the sendfile() system call which does an
  in-kernel copy directly from the zip executable structure. Also note
  that red bean zip executables can be deployed easily to all platforms,
  since these native executables work on Linux, Mac, BSD, and Windows.

- Address sanitizer now works very well

ape/ape.S

@@ -236,9 +236,6 @@ pc:	cld
 	ljmp	$0,$REAL(realmodeloader)
 	.endfn	pc,globl,hidden
 
-/	Be gentler on Unix line buffer impls.
-	.byte	0x0a
-
 /	Determines disk geometry.
 /
 /	We use imperial measurements for storage systems so the software
@@ -1055,9 +1052,9 @@ realmodeloader:
 	call	rlinit
 	call	sinit4
 	mov	$VIDYA_MODE,%di
+	call	vinit
 	mov	%es,XLM(VIDEO_POSITION_FAR_POINTER)
 	mov	%ax,XLM(VIDEO_POSITION_FAR_POINTER)+2
-	call	vinit
 	mov	$REAL(.Lstr.ape),%di
 	call	rvputs
 	.optfn	_start16
@@ -1370,8 +1367,8 @@ vtput:	push	%bp
 	mov	%di,%dx
 	bband	VIDYA_REWIND,%dh,%dl
 	bbadd	VIDYA_SIZE,%dh,%dl
-	bbmov	VIDYA_COLUMNS*2,%bx,%bh,%bl
-0:	cmp	%di,%dx
+	bbmov	VIDYA_COLUMNS*2-2,%bx,%bh,%bl
+0:	cmp	%dx,%di
 	je	6f
 	ja	3f
 	lodsb				# todo: utf8 → cp437
@@ -1523,12 +1520,12 @@ longmodeloader:
 /	Long Mode Hardware Check
 lcheck:	push	%bp
 	mov	%sp,%bp
-	pushfw				# check for i8086 / i8088 / i80186
+	pushf				# check for i8086 / i8088 / i80186
 	pop	%ax
-	and	$0b111<<12,%ax		# see intel manual volume 1 §19.1.2
-	jnz	9f
-	pushfl				# now check for later model of 80486
-	pop	%eax			# test ability to *change* cpuid bit
+	test	$0x80,%ah		# see intel manual volume 1 20.1.2
+	jnz	9f			# we now assume 32bit is supported
+	pushfl				# now check for i386 or early i486
+	pop	%eax			# test ability to change cpuid bit
 	mov	%eax,%ecx
 	mov	$1<<21,%ebx
 	xor	%ebx,%eax
@@ -1537,8 +1534,8 @@ lcheck:	push	%bp
 	pushfl
 	pop	%eax
 	cmp	%eax,%ecx
-	je	12f
-	and	%ebx,%eax		# puts cpuid bit in the on position
+	je	12f			# we assume cpuid inst is available
+	or	%ebx,%eax		# puts cpuid bit in the on position
 	push	%eax
 	popfl
 	mov	$0x80000000,%edi	# get amd ext cpuid thingy length
@@ -1549,7 +1546,7 @@ lcheck:	push	%bp
 	jl	10f
 	mov	%edi,%eax
 	cpuid
-	mov	$1<<29/*LM*/,%edi	# check for nexgen32e support
+	mov	$1<<29,%edi		# need nexgen32e long mode support
 	and	%edi,%edx
 	cmp	%edi,%edx
 	jne	10f

ape/config.h

@@ -41,7 +41,7 @@
  * @see ape/lib/vidya.h
  */
 #ifndef VIDYA_MODE
-#define VIDYA_MODE VIDYA_MODE_MDA
+#define VIDYA_MODE VIDYA_MODE_CGA
 #endif
 
 /* FPU Control Word (x87) Exception Masks