TP3/shell/tests/exec/rtdrv.s

# rtdrv.s -- call runtime entries, with known arguments, and report what
# happened.  Assembled by tests/rt_exec.py into a complete .COM image.
#
# This replaces the Unicorn harness.  The expectations did not change; only the
# machine did.  Everything here exists because qemu, unlike an emulator with a
# Python API, gives you one thing: a serial port.  So a check has to be
# expressed as a program that reports on itself.
#
# The report is a framed record on the serial port:
#
#     01 <case index, 2 hex digits> 02  <whatever the entries printed>  03
#     <dumplen bytes at dumpaddr, 2 hex digits each>                  04
#
# The four control bytes occur in no expected output, and rt_exec.py REFUSES to
# run a case whose expectation contains one -- so a marker can never be mistaken
# for output, and a driver that emitted nothing is a parse failure rather than
# a silent pass.
#
# Why one qemu boot per check instead of one boot for all of them: the runtime
# keeps state that outlives a call -- the one-character pushback slot, and the
# input cursor the boot sector's INT 21h shim owns.  One boot for everything
# would make each check depend on the ones before it, so a check could fail
# because of its neighbour and a green run would prove less than it appears to.
# A boot costs about a tenth of a second and 35 of them cost under four, which
# buys every check a machine that has provably never executed anything.  (The
# input descriptor is still re-armed on every boot, because it lives in the
# image and the image is the same bytes each time.)
#
# Two things about the 8086 shape the code below, and both were found by
# running it rather than by reading it:
#
#   * Every entry preserves BP and SP and NO other register.  So the cursor
#     into the case record is BP: a loop counter in CX or DI would be destroyed
#     by the first call.  The entry's own BP frame is pushed and restored, so
#     our BP comes back.
#
#   * `movb n(%bp), %cl' leaves the HIGH byte of CX exactly as it was.  Reading
#     the input length that way and then writing CX to INLEN handed the boot
#     sector's INT 21h shim a 16-bit length with an undefined top half.  The
#     8086 has no memory-to-memory move and no zero-extending byte load, so the
#     high half has to be cleared by hand, every time.
#
#   * `dec' sets the sign flag from the RESULT, so `decw cnt / js done' runs the
#     body for cnt = 1 (1 -> 0, SF clear) and stops on the wrap (0 -> FFFF).
#     It reads like an off-by-one and is not; the comment at the loop says so
#     again because the next person will wonder.
#
# The image is assembled in ONE piece, here, so every address is a label or an
# .org and nothing has to be agreed with Python in two places.  What Python does
# have to agree about -- the runtime's base, and the input descriptor -- is
# checked rather than trusted: it assembles this file and then asserts that the
# blob it got from RtProbe really is at RT_BASE in the bytes that came out.

	.set	LOAD_BIAS, 0x0100	# a .COM lives at CS:0100 (that is the PSP)
	.set	SOH, 0x01
	.set	STX, 0x02
	.set	ETX, 0x03
	.set	EOT, 0x04

# Restated from tests/exec/bootcom.s's layout block ON PURPOSE.  A harness that
# asks the boot sector where its input buffer is proves only that the two agree
# with each other; two independent statements of the same layout have to be
# written down, and a disagreement is a loud failure rather than a program that
# is fed nothing.  (Same reasoning, and the same lesson, as the hard-coded
# RT_SZ that run_com_tests.sh used to carry: the descriptor has to be where the
# shim looks, and the only way to be sure is to have written both down and
# checked.)
	.set	INLEN, 0x7000		# word: how many input bytes follow
	.set	INCUR, 0x7002		# word: index into INBUF, NOT an address
	.set	INBUF, 0x7004		# the bytes themselves

# The case record, as rt_exec.py writes it.  These offsets are the contract; the
# two places that read them (this file, and case_bytes() over there) are
# separate statements of it on purpose, and the cases only pass if both are
# right.  SLOT0 is the one that was wrong the first time round.
	.set	OFF_DUMPLEN, 0	# word  how many bytes to report
	.set	OFF_DUMPADR, 2	# word  image offset to report them from
	.set	OFF_INLEN, 4	# byte  bytes of input to hand the shim
	.set	OFF_INBUF, 5	# byte  inbuf[8]
	.set	OFF_CASE, 13	# word  the index printed in the header (4 hex digits)
	.set	OFF_NCALLS, 15	# byte  how many call slots follow
	.set	SLOT0, 16		#      call slots, 12 bytes each:
					#      +0 word entry, +2 word arg A,
					#      +4 byte flags, +5 pad,
					#      +6 word arg B, +8 word CX,
					#      +10 pad
	.set	SLOT_SZ, 12
	.set	CASE_SZ, 64		# 16 + 4 slots

# The image layout.  RT_BASE is where the runtime blob goes; everything else is
# above 0x0800 so that a runtime which grew by a few hundred bytes would not
# silently run into the test scaffolding.  rt_exec.py asserts
# RT_BASE + blob size <= HDR, so the bound is a checked one.
	.set	RT_BASE, 0x0190
	.set	HDR, 0x4000
	.set	FMTDEST, DSHIFT+0x2430	# 64-byte destination for real_fmt
	.set	ASCSRC, DSHIFT+0x2470	# ASCIIZ sources for real_val
	.set	DATA, 0x5000
	.set	DSHIFT, 0x2EF0
	.set	DLEN, 32			# bytes of data area for initmem to clear
	.set	STORE, DSHIFT+0x2140		# where a read entry's result is stored
	.set	WSTR, DSHIFT+0x2150		# a string for the wrstr case: length + chars
	.set	WSTR_EMPTY, DSHIFT+0x2158	# the same, with a length of 0
	.set	CASE, DSHIFT+0x2160		# the case record
	.set	D_DUMPLEN, DSHIFT+0x21a0	# the driver's own three words
	.set	D_DUMPADR, DSHIFT+0x21a2
	.set	D_CNT, DSHIFT+0x21a4
	.set	D_AX, DSHIFT+0x21a6		# last call's AX, for the comparison cases
	.set	RDSTR_DST, DSHIFT+0x21b0	# destination for the rdstr cases
	.set	SST_HELLO, DSHIFT+0x21c0	# a short source string for strstore
	.set	SST_LONG, DSHIFT+0x21d0	# a source longer than a small max
	.set	SST_EMPTY, DSHIFT+0x21e0	# an empty source string
	.set	SST_DST, DSHIFT+0x21f0		# destination for the strstore cases
	.set	SST_CAT, DSHIFT+0x2200		# destination for the strcat cases, with a
					# length to append to -- unlike SST_DST,
					# which strstore overwrites
	.set	SST_CAT0, DSHIFT+0x2210	# ...and one that starts empty
	.set	SST_WORLD, DSHIFT+0x2220	# a source distinct from SST_HELLO
	.set	R_BLK1, DSHIFT+0x2230
	.set	R_BLK2, DSHIFT+0x2240
	.set	R_BLK3, DSHIFT+0x2250
	.set	R_BLK4, DSHIFT+0x2260
	.set	R_BLK5, DSHIFT+0x2270
	.set	R_BLK6, DSHIFT+0x2280
	.set	R_BLK7, DSHIFT+0x2290
	.set	R_BLK8, DSHIFT+0x22a0
	.set	R_BLK9, DSHIFT+0x22b0
	.set	R_BLK10, DSHIFT+0x22c0
	.set	R_BLK11, DSHIFT+0x22d0
	.set	R_BLK12, DSHIFT+0x22e0
	.set	R_BLK13, DSHIFT+0x22f0
	.set	R_BLK14, DSHIFT+0x2300
	.set	R_BLK15, DSHIFT+0x2310
	.set	R_BLK16, DSHIFT+0x2320
	.set	R_BLK17, DSHIFT+0x2330
	.set	R_BLK18, DSHIFT+0x2340
	.set	R_BLK19, DSHIFT+0x2350
	.set	R_BLK20, DSHIFT+0x2360
	.set	R_BLK21, DSHIFT+0x2370
	.set	R_BLK22, DSHIFT+0x2380
	.set	R_BLK23, DSHIFT+0x2390
	.set	R_BLK24, DSHIFT+0x23a0
	.set	R_BLK25, DSHIFT+0x23b0
	.set	R_BLK26, DSHIFT+0x23c0
	.set	R_BLK27, DSHIFT+0x23d0
	.set	R_BLK28, DSHIFT+0x23e0
	.set	R_BLK29, DSHIFT+0x23f0
	.set	R_BLK30, DSHIFT+0x2400
	.set	R_BLK31, DSHIFT+0x2410
	.set	R_BLK32, DSHIFT+0x2500
	.set	R_BLK33, DSHIFT+0x2510
	.set	R_BLK34, DSHIFT+0x2520
	.set	R_BLK35, DSHIFT+0x2530
	.set	R_BLK36, DSHIFT+0x2540
	.set	FILEBLK, DSHIFT+0x2a00	# the 132-byte file control block
	.set	SETA, DSHIFT+0x2580
	.set	SETB, DSHIFT+0x2590
	.set	SETC, DSHIFT+0x25a0
	.set	SETD, DSHIFT+0x25b0
	.set	SET2A, DSHIFT+0x25c0
	.set	SET2B, DSHIFT+0x25d0
	.set	SET2D, DSHIFT+0x25e0

	.code16
	.text
	.globl	_start

# The entry JMP -- the same three bytes every image this compiler writes opens
# with.  bootcom.s jumps to 0000:0100, which is this instruction.  It is
# written as raw bytes rather than `jmp drive' because gas would shorten that to
# a two-byte EB 00 short jump, and the byte it dropped would then be executed as
# the first instruction of the driver.
_start:
	.byte	0xE9			# JMP rel16
	.word	drive - _start - 3

# --------------------------------------------------------------- the driver
drive:
	cld

	# 1. Poison the two places a check is allowed to look.  STORE gets EEEH so
	#    a read entry that stores nothing is visible as such, and the data
	#    area gets AAH so initmem has something to clear.  The storage below
	#    is zeroed; the poison is what turns a zero into a RESULT.
	movw	$STORE + LOAD_BIAS, %si
	movw	$0xEEEE, %ax
	movw	%ax, (%si)
	movw	$DATA + LOAD_BIAS, %si
	movw	$DLEN, %cx
	movb	$0xAA, %al
.Lpoison:
	movb	%al, (%si)
	incw	%si
	loop	.Lpoison

	# BP is the case-record cursor, and it is the only register that survives a
	# call into the runtime, so everything the loop needs is read through it
	# or parked in the driver's own words first.
	movw	$CASE + LOAD_BIAS, %bp

	# 2. Open the record: SOH, the case index as two hex digits, STX.
	movb	$SOH, %al
	call	putc
	movw	OFF_CASE(%bp), %ax
	movw	%ax, %bx
	movb	%bh, %al
	call	hexb
	movb	%bl, %al
	call	hexb
	movb	$STX, %al
	call	putc

	# 3. Arm the input.  INCUR is an INDEX into INBUF, and zeroing it is what
	#    makes this boot's input start at its first byte.  CX is cleared
	#    first: see the note at the top about the high byte of CX.
	xorw	%cx, %cx
	movb	OFF_INLEN(%bp), %cl
	movw	%cx, INLEN
	movw	$0, INCUR
	movw	$CASE + OFF_INBUF + LOAD_BIAS, %si
	movw	$INBUF, %di
	xorw	%ax, %ax
	repe	cmpsb

	# 4. The calls.  dumplen and the report address are needed after the loop,
	#    by which time BP has moved, so they are parked now; so is the count,
	#    because CX is gone by the second iteration.
	movw	OFF_DUMPLEN(%bp), %ax
	movw	%ax, D_DUMPLEN + LOAD_BIAS
	movw	OFF_DUMPADR(%bp), %ax
	movw	%ax, D_DUMPADR + LOAD_BIAS
	xorw	%ax, %ax
	movb	OFF_NCALLS(%bp), %al
	movw	%ax, D_CNT + LOAD_BIAS
	addw	$SLOT0, %bp		# BP now points AT the first call slot
.Lcall:
	decw	D_CNT + LOAD_BIAS	# 1 -> 0 has SF clear, so the body runs once;
	jns	.Lgo			# 0 -> FFFF is what ends the loop
	jmp	.Lcalldone
.Lgo:
	call	doslot
	addw	$SLOT_SZ, %bp
	jmp	.Lcall
.Lcalldone:

	# 5. Close the output half and report the memory.  A store that never
	#    happened is the EEEH left in step 1, which is why it is there.
	movb	$ETX, %al
	call	putc
	movw	D_DUMPLEN + LOAD_BIAS, %cx
	jcxz	.Lnodump
	movw	D_DUMPADR + LOAD_BIAS, %si
	addw	$LOAD_BIAS, %si
.Ldump:
	lodsb
	call	hexb
	loop	.Ldump
.Lnodump:
	movb	$EOT, %al
	call	putc

	# 6. Exit.  Reaching here IS the assertion that every entry returned: an
	#    entry that hung produces no EOT, and the harness says so.
	movw	$0x4C00, %ax		# INT 21h AH=4Ch, AL=0
	int	$0x21

# doslot: call the entry described by the 12 bytes at BP, with the same
# conventions Compiler.IoCall uses -- 16-bit argument(s) on the stack, popped
# by the caller -- except for initmem, which takes the header in AX.
#
# Flags (the byte at +4):
#   1  F_STACK   push the word at +2; the caller pops one word.
#   2  F_AX      take the word at +2 in AX instead.
#   4  F_INL     the argument follows the call, not on the stack.
#   8  F_STACK2  push the word at +6 FIRST and the word at +2 second, so +2
#                lands at [BP+4] and +6 at [BP+6]; the caller pops two words.
#                strstore wants exactly that: dest at [BP+4], source at [BP+6].
#   16 F_CX      load CX from the word at +8 before the call.  rdstr and
#                strstore both take their maximum length in CX, a register the
#                record has no other way to reach, and neither may borrow it
#                from whatever the previous case left behind.
#
# The flags are re-read after the call because the entry has just used AX.
doslot:
	movb	4(%bp), %al
	testb	$64, %al
	jnz	.Lfourstack
	testb	$32, %al
	jnz	.Lthreestack
	testb	$8, %al
	jnz	.Ltwostack
	testb	$1, %al
	jz	.Lnostack
	pushw	2(%bp)
	jmp	.Lnostack
.Ltwostack:
	pushw	6(%bp)			# arg B: the source, ends at [BP+6]
	pushw	2(%bp)			# arg A: the destination, ends at [BP+4]
	jmp	.Lnostack
.Lthreestack:
	pushw	8(%bp)			# [BP+8]
	pushw	6(%bp)			# [BP+6]
	pushw	2(%bp)			# [BP+4]
	jmp	.Lnostack
.Lfourstack:
	pushw	10(%bp)			# [BP+10]
	pushw	8(%bp)			# [BP+8]
	pushw	6(%bp)			# [BP+6]
	pushw	2(%bp)			# [BP+4]
.Lnostack:
	testb	$2, %al
	jz	.Lnoax
	movw	2(%bp), %ax
.Lnoax:
	testb	$16, %al
	jz	.Lnocx
	movw	8(%bp), %cx
.Lnocx:
	movw	(%bp), %si		# image-absolute, as RT_Entry reports it
	addw	$LOAD_BIAS, %si		# so the load bias is added here, not baked in
	testb	$4, %al
	jnz	.Linl
	call	*%si
	movw	%ax, D_AX + LOAD_BIAS	# observable return value
	movb	4(%bp), %al
	testb	$64, %al
	jnz	.Lcleanfour
	testb	$32, %al
	jnz	.Lcleanthree
	testb	$8, %al
	jnz	.Lcleantwo
	testb	$1, %al
	jz	.Lnoclean
	addw	$2, %sp		# caller-cleaned
.Lnoclean:
	ret
.Lcleantwo:
	addw	$4, %sp
	ret
.Lcleanthree:
	addw	$6, %sp
	ret
.Lcleanfour:
	addw	$8, %sp
	ret

# wrtinl's argument is NOT a stack word: the entry reads a length byte and that
# many characters from its own return address.  That is the caller's half of
# the contract, so it is written literally here -- the length byte and the
# characters must be the bytes immediately after the call, which is why this is
# a second copy of the instruction rather than a jump.  The compiler's own
# placement of the same three things is what the string-literal fixtures in
# run_com_exec.py check; duplicating a variable one here would be a second
# thing to keep right, and a check that cannot fail is not a check.
.Linl:
	call	*%si
	.byte	5
	.byte	'h', 'e', 'l', 'l', 'o'
	ret

# putc: AL to the serial port.  No status polling -- qemu's 16550 always accepts,
# and a poll that never went ready would hang the harness instead of failing it.
putc:
	pushw	%ax
	movw	$0x03f8, %dx
	outb	%al, %dx
	popw	%ax
	ret

# hexb: AL as two uppercase hex digits, high nibble first.
#
# The 8086 has no `SHR r/m16, imm8' and no shift-by-four, so the high nibble
# comes from four one-bit shifts through CL.  Both facts have to be written
# down: gas assembles `shr $4, %ah' without complaint and rejects `shrw $1, %ah'
# outright, so the only thing standing between this file and an image that
# assembles cleanly and dies on a real 8086 is refusing the modern encodings.
hexb:
	pushw	%ax
	pushw	%cx
	movb	%al, %ah
	movb	$1, %cl
	shrw	%cl, %ax
	shrw	%cl, %ax
	shrw	%cl, %ax
	shrw	%cl, %ax
	popw	%cx
	call	putdig
	popw	%ax
	andb	$0x0f, %al
	movb	%al, %ah
	call	putdig
	ret

# putdig: the nibble in AH as one character, moved into AL so that setting AH for
# INT 21h AH=02h cannot overwrite the digit it is about to print.
putdig:
	movb	%ah, %al
	cmpb	$10, %al
	jb	.Ldigit
	addb	$0x37, %al		# 0Ah + 37h = 'A'
	jmp	.Lemit
.Ldigit:
	addb	$0x30, %al		# '0'
.Lemit:
	movb	$2, %ah
	int	$0x21
	ret

# --------------------------------------------------------------- the image
# The runtime blob, from tests/RtProbe.mod built at RT_BASE.  The gap is the
# checked bound: rt_exec.py asserts that 0x0180..RT_BASE is still all zeros, so
# a driver that outgrew its space fails the suite instead of overwriting the
# library it is testing.
	.org	RT_BASE
	.incbin	"rtblob.bin"

# The program header initmem is handed: +0 flag, +2 code, +4 data base, +6 data
# end.  Built HERE, from the same DATA and DLEN the poison loop uses, because
# the compiler's own header layout is a separate claim with its own check and
# this harness is not that check.  The two fields initmem READS are memory
# addresses, so they carry the bias; the caller passes AX the header's memory
# address too, which is the one thing rt_exec.py gets right only by saying so
# here and in case_bytes().
	.org	HDR
HDR:
	.word	1			# hdrFlag
	.word	0			# hdrCS, unused by initmem
	.word	DATA + LOAD_BIAS		# hdrDS   = data base
	.word	DATA + DLEN + LOAD_BIAS	# hdrHeap = data end

	.org	DATA
	.zero	DLEN			# poisoned to AAH by the driver

	.org	STORE
	.zero	2			# poisoned to EEEH by the driver

# A string for the wrstr case: a length byte and that many characters, which is
# the layout a compiled `string [n]' variable has.  It sits above the poisoned
# area so the poison never touches it, and rt_exec.py restates its address - the
# two must agree or the case reads whatever bytes are there and prints them.
	.org	WSTR
	.byte	5
	.byte	'h', 'e', 'l', 'l', 'o'

	.org	WSTR_EMPTY
	.byte	0			# a length of 0: an empty string

	.org	CASE
	.incbin	"rtcase.bin"

	.org	D_DUMPLEN
	.zero	6			# D_DUMPLEN, D_DUMPADR, D_CNT

# --- strings for the string entries ----------------------------------------
# A compiled `string [n]' variable is a length byte and n characters, and that
# is the layout rdstr writes and strstore reads.  Each DESTINATION is
# pre-filled with 0xEE so a byte the entry does NOT write is visibly still
# there -- that is how "the tail past the new length is left untouched" becomes
# a checked claim rather than a comment.  The sources are distinct addresses so
# one image can offer a short string, one longer than a small max, and an empty
# one, without any case depending on a previous case's leftovers.
	.org	RDSTR_DST
	.fill	16, 1, 0xEE

	.org	SST_HELLO
	.byte	5, 'h', 'e', 'l', 'l', 'o'

	.org	SST_LONG
	.byte	8, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'

	.org	SST_EMPTY
	.byte	0			# a length of 0: an empty string

	.org	SST_DST
	.fill	16, 1, 0xEE

# strcat reads the DESTINATION's length, so its destinations are seeded with a
# real string rather than 0xEE -- and 0xEE would in fact be a 238-character
# length, which is exactly the "string too long" error the entry has to raise.
# SST_CAT holds `hello', SST_CAT0 is empty, and SST_WORLD is a source that is
# not SST_HELLO so an append is visible as an append and not as a coincidence.
	.org	SST_CAT
	.byte	5, 'h', 'e', 'l', 'l', 'o'
	.fill	10, 1, 0xEE

	.org	SST_CAT0
	.byte	0			# a length of 0: nothing to append to
	.fill	15, 1, 0xEE

	.org	SST_WORLD
	.byte	5, 'w', 'o', 'r', 'l', 'd'

# 12-byte MBF blocks for real_add/real_sub: a at +0, b at +6.
	.org	R_BLK1
	.byte	0x81, 0x00, 0x00, 0x00, 0x00, 0x00, 0x82, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK2
	.byte	0x82, 0x00, 0x00, 0x00, 0x00, 0x40, 0x83, 0x00, 0x00, 0x00, 0x00, 0x20
	.org	R_BLK3
	.byte	0x83, 0x00, 0x00, 0x00, 0x00, 0x20, 0x82, 0x00, 0x00, 0x00, 0x00, 0x40
	.org	R_BLK4
	.byte	0x81, 0x00, 0x00, 0x00, 0x00, 0x00, 0x81, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK5
	.byte	0x8A, 0x00, 0x00, 0x00, 0x00, 0x7A, 0x81, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK6
	.byte	0x82, 0x00, 0x00, 0x00, 0x00, 0xC0, 0x82, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK7
	.byte	0x86, 0x00, 0x00, 0x00, 0x00, 0x28, 0x8A, 0x00, 0x00, 0x00, 0x00, 0x7A
	.org	R_BLK8
	.byte	0x8F, 0x00, 0x00, 0x00, 0xFE, 0x7F, 0x81, 0x00, 0x00, 0x00, 0x00, 0x00

	.org	R_BLK9
	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x83, 0x00, 0x00, 0x00, 0x00, 0x20
	.org	R_BLK10
	.byte	0x82, 0x00, 0x00, 0x00, 0x00, 0xC0, 0x82, 0x00, 0x00, 0x00, 0x00, 0x80

# Division pairs for real_div.
	.org	R_BLK11
	.byte	0x83, 0x00, 0x00, 0x00, 0x00, 0x40, 0x82, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK12
	.byte	0x84, 0x00, 0x00, 0x00, 0x00, 0x20, 0x82, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK13
	.byte	0x84, 0x00, 0x00, 0x00, 0x00, 0x70, 0x82, 0x00, 0x00, 0x00, 0x00, 0x40
	.org	R_BLK14
	.byte	0x8A, 0x00, 0x00, 0x00, 0x00, 0x7A, 0x82, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK15
	.byte	0x83, 0x00, 0x00, 0x00, 0x00, 0xC0, 0x82, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK16
	.byte	0x83, 0x00, 0x00, 0x00, 0x00, 0x40, 0x82, 0x00, 0x00, 0x00, 0x00, 0x80
	.org	R_BLK17
	.byte	0x83, 0x00, 0x00, 0x00, 0x00, 0xC0, 0x82, 0x00, 0x00, 0x00, 0x00, 0x80
	.org	R_BLK18
	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x83, 0x00, 0x00, 0x00, 0x00, 0x20
	.org	R_BLK19
	.byte	0x83, 0x00, 0x00, 0x00, 0x00, 0x20, 0x82, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK20
	.byte	0x86, 0x00, 0x00, 0x00, 0x00, 0x28, 0x83, 0x00, 0x00, 0x00, 0x00, 0x40

# Fractional blocks: real_int truncates `a'; real_cmp compares the pair.
	.org	R_BLK21
	.byte	0x82, 0xCD, 0xCC, 0xCC, 0xCC, 0x6C, 0x82, 0xCD, 0xCC, 0xCC, 0xCC, 0x6C
	.org	R_BLK22
	.byte	0x82, 0x9A, 0x99, 0x99, 0x99, 0x79, 0x82, 0xCD, 0xCC, 0xCC, 0xCC, 0x6C
	.org	R_BLK23
	.byte	0x82, 0xCD, 0xCC, 0xCC, 0xCC, 0xEC, 0x82, 0x9A, 0x99, 0x99, 0x99, 0xF9
	.org	R_BLK24
	.byte	0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7F, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK25
	.byte	0x80, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK26
	.byte	0x8E, 0x00, 0x00, 0x00, 0xE7, 0x40, 0x8E, 0x00, 0x00, 0x00, 0xE6, 0x40
	.org	R_BLK27
	.byte	0x82, 0x00, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK28
	.byte	0x82, 0x00, 0x00, 0x00, 0x00, 0xA0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK29
	.byte	0x80, 0x0A, 0xD7, 0xA3, 0x70, 0x7D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK30
	.byte	0x81, 0x33, 0x33, 0x33, 0x33, 0x73, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00

# 2^40: above reint's 0A8h early return, so it must come back unchanged.
	.org	R_BLK31
	.byte	0xA9, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00

# ASCIIZ sources for real_val.
	.org	ASCSRC
	.ascii	"3.5\x00"
	.ascii	"-2.25\x00"
	.ascii	"1E3\x00"
	.ascii	"0.5\x00"
	.ascii	"12345.75\x00"
	.ascii	"3.5x\x00"
	.ascii	"1E\x00"
	.ascii	"1E40\x00"
	.ascii	"\x00"
	.ascii	".5\x00"
	.ascii	"1.2.3\x00"
	.ascii	"35\x00"
	.ascii	"5E-1\x00"
	.ascii	"5.\x00"
	.ascii	"5.0\x00"
	.ascii	"12345\x00"
	.ascii	"1234575\x00"
	.ascii	"1234.5\x00"
	.ascii	"1000\x00"
	.ascii	"123\x00"
	.ascii	"1234\x00"
	.ascii	"12340\x00"
	.ascii	"12341\x00"
	.ascii	"12341E0\x00"
	.ascii	"12345E0\x00"

# add-core probes
	.org	R_BLK32
	.byte	0x8E, 0x00, 0x00, 0x00, 0xD0, 0x40, 0x83, 0x00, 0x00, 0x00, 0x00, 0x20
	.org	R_BLK33
	.byte	0x8E, 0x00, 0x00, 0x00, 0xD0, 0x40, 0x81, 0x00, 0x00, 0x00, 0x00, 0x00

# multiplication-by-one probes
	.org	R_BLK34
	.byte	0x8E, 0x00, 0x00, 0x00, 0xD4, 0x40, 0x81, 0x00, 0x00, 0x00, 0x00, 0x00
	.org	R_BLK35
	.byte	0x8E, 0x00, 0x00, 0x00, 0xE4, 0x40, 0x81, 0x00, 0x00, 0x00, 0x00, 0x00

	.org	R_BLK36
	.byte	0x8E, 0x00, 0x00, 0x00, 0xD0, 0x40, 0x81, 0x00, 0x00, 0x00, 0x00, 0x00

# Set buffers for set_op/set_cmp/set_copy.
	.org	SETA
	.byte	0x0A, 0x00, 0x00, 0x00
	.org	SETB
	.byte	0x18, 0x00, 0x00, 0x00
	.org	SETC
	.byte	0x02, 0x00, 0x00, 0x00
	.org	SETD
	.byte	0x00, 0x00, 0x00, 0x00
	.org	SET2A
	.byte	0x0A, 0x0F
	.org	SET2B
	.byte	0x18, 0x03
	.org	SET2D
	.byte	0x00, 0x00

# File control block for the file_assign case.
	.org	FILEBLK
	.zero	132