#!/usr/bin/env python3
""" survey.py
Resolves label references and substitutes them with literal values.
>>> from io import StringIO
>>> # doctest: +REPORT_NDIFF
... print(subv.join_all(survey(StringIO('''
... == code 0x80000000
... main:
... # load 0x10010000 (UART0) into t0
... 37/u 5/rd 10010/imm20
... # store 0x48 (H) in UART0+0
... 13/i 6/rd 0/funct3 0/rs 48/imm12
... 23/s 2/funct3 5/rs1 0/imm12 6/rs2
... # store 0x65 (e) in UART0+0
... 13/i 6/rd 0/funct3 0/rs 65/imm12
... 23/s 2/funct3 5/rs1 0/imm12 6/rs2
... # store 0x6c (l) in UART0+0
... 13/i 6/rd 0/funct3 0/rs 6c/imm12
... 23/s 2/funct3 5/rs1 0/imm12 6/rs2
... # store 0x6c (l) in UART0+0
... 13/i 6/rd 0/funct3 0/rs 6c/imm12
... 23/s 2/funct3 5/rs1 0/imm12 6/rs2
... # store 0x6f (o) in UART0+0
... 13/i 6/rd 0/funct3 0/rs 6f/imm12
... 23/s 2/funct3 5/rs1 0/imm12 6/rs2
... # store 0x0a (\\\\n) in UART0+0
... 13/i 6/rd 0/funct3 0/rs a/imm12
... 23/s 2/funct3 5/rs1 0/imm12 6/rs2
... # jump back up to the top
... 6f/j 0/rd main/off21
... '''[1:-1]))))
== code 0x80000000
# main:
# load 0x10010000 (UART0) into t0
37/u 5/rd 10010/imm20
# store 0x48 (H) in UART0+0
13/i 6/rd 0/funct3 0/rs 48/imm12
23/s 2/funct3 5/rs1 0/imm12 6/rs2
# store 0x65 (e) in UART0+0
13/i 6/rd 0/funct3 0/rs 65/imm12
23/s 2/funct3 5/rs1 0/imm12 6/rs2
# store 0x6c (l) in UART0+0
13/i 6/rd 0/funct3 0/rs 6c/imm12
23/s 2/funct3 5/rs1 0/imm12 6/rs2
# store 0x6c (l) in UART0+0
13/i 6/rd 0/funct3 0/rs 6c/imm12
23/s 2/funct3 5/rs1 0/imm12 6/rs2
# store 0x6f (o) in UART0+0
13/i 6/rd 0/funct3 0/rs 6f/imm12
23/s 2/funct3 5/rs1 0/imm12 6/rs2
# store 0x0a (\\n) in UART0+0
13/i 6/rd 0/funct3 0/rs a/imm12
23/s 2/funct3 5/rs1 0/imm12 6/rs2
# jump back up to the top
6f/j 0/rd -34/imm21
>>> # doctest: +REPORT_NDIFF
... print(subv.join_all(survey(StringIO('''
... == code 0x80000000
... # repeatedly print "Hi\\\\n"
... main:
... # load 0x10010000 (UART0) into t0
... 37/u 5/rd/t0 10010/imm20
... # store 0x48 (H) in UART0+0
... 13/i 0/subop/add 6/rd/t1 0/rs/x0 48/imm12
... 23/s 2/subop/word 5/rs/t0 6/rs/t1 0/off12
... # store 0x69 (i) in UART0+0
... 13/i 0/subop/add 6/rd/t1 0/rs/x0 69/imm12
... 23/s 2/subop/word 5/rs/t0 6/rs/t1 0/off12
... # store 0x0a (\\\\n) in UART0+0
... 13/i 0/subop/add 6/rd/t1 0/rs/x0 0a/imm12
... 23/s 2/subop/word 5/rs/t0 6/rs/t1 0/off12
... 17/u 7/rd/t2 main/off20hi
... 67/i 0/subop 0/rd/x0 7/rs/t2 main+4/off12lo
... '''[1:-1]))))
== code 0x80000000
# repeatedly print "Hi\\n"
# main:
# load 0x10010000 (UART0) into t0
37/u 5/rd/t0 10010/imm20
# store 0x48 (H) in UART0+0
13/i 0/subop/add 6/rd/t1 0/rs/x0 48/imm12
23/s 2/subop/word 5/rs/t0 6/rs/t1 0/off12
# store 0x69 (i) in UART0+0
13/i 0/subop/add 6/rd/t1 0/rs/x0 69/imm12
23/s 2/subop/word 5/rs/t0 6/rs/t1 0/off12
# store 0x0a (\\n) in UART0+0
13/i 0/subop/add 6/rd/t1 0/rs/x0 a/imm12
23/s 2/subop/word 5/rs/t0 6/rs/t1 0/off12
17/u 7/rd/t2 0/imm20
67/i 0/subop 0/rd/x0 7/rs/t2 -1c/imm12
"""
import subv
def observe(word, pc, map):
"""resolve a label reference.
>>> observe((3, '3'), 0, {})
(3, '3')
>>> subv.format_part(observe(('label', 'imm32'), 0, {'label': 0x1234}))
'1234/imm32'
>>> subv.format_part(observe(('label-2', 'imm20',), 0, {'label': 0x1234}))
'1232/imm20'
>>> subv.format_part(observe(('label', 'off32'), 0x1000, {'label': 0x1234}))
'234/imm32'
>>> subv.format_part(observe(('label+4', 'off32'), 0x1000, {'label': 0x1234}))
'238/imm32'
>>> subv.format_part(observe(('label', 'off32'), 0x1234, {'label': 0x1000}))
'-234/imm32'
>>> subv.format_part(observe(('label', 'off20hi'), 0x1000, {'label': 0x3234}))
'2/imm20'
>>> subv.format_part(observe(('label', 'off12lo'), 0x1000, {'label': 0x3234}))
'234/imm12'
>>> subv.format_part(observe(('label', 'off20hi'), 0x3234, {'label': 0x1000}))
'-2/imm20'
>>> subv.format_part(observe(('label', 'off12lo'), 0x3234, {'label': 0x1000}))
'-234/imm12'
>>> observe(('label', 'imm32'), 0, {})
Traceback (most recent call last):
...
ValueError: undefined label 'label'
>>> observe(('label', 'imm8'), 0, {'label': 0x1234})
Traceback (most recent call last):
...
ValueError: label reference out of range (8 bit): 'label' (0x1234)
"""
if not subv.is_reference(word):
if len(word) != 2:
return word
ref = subv.parse_immediate(word[1])
if not ref or "split" not in ref:
return word
value = word[0]
sgn = -1 if value < 0 else 1
value *= sgn
if ref["split"] == "hi" and ref["size"] == 20:
value = value >> 12
elif ref["split"] == "lo" and ref["size"] == 12:
value = value & 0xFFF
else:
raise ValueError(
"unknown label split mode {mode}{size}{split}".format(**ref)
)
return (value, "imm{size}".format(**ref))
ref = subv.parse_reference(word)
if ref["label"] not in map:
raise ValueError("undefined label '{}'".format(ref["label"]))
value = map[ref["label"]] + ref["offset"]
if ref["mode"] == "off":
value -= pc
if "split" in ref:
sgn = -1 if value < 0 else 1
value *= sgn
if ref["split"] == "hi" and ref["size"] == 20:
value = value >> 12
elif ref["split"] == "lo" and ref["size"] == 12:
value = value & 0xFFF
else:
raise ValueError(
"unknown label split mode {mode}{size}{split}".format(**ref)
)
value *= sgn
if value > 0:
if value >= (1 << ref["size"]):
raise ValueError(
"label reference out of range ({size} bit): '{label}' (0x{:x})".format(
value, **ref
)
)
else:
if value < -(1 << (ref["size"] - 1)):
raise ValueError(
"label reference out of range ({size} bit): '{label}' (-0x{:x})".format(
abs(value), **ref
)
)
return (value, "imm{size}".format(**ref))
@subv.with_parsed_lines
def survey(iter):
queue = []
map = {}
addr, bitcount = -1, 0
for segment, line in iter:
line["addr"] = addr
queue.append(line)
# step forward addr
type = line["type"]
if type == "segment":
addr, bitcount = line["segment"][1], 0
elif type == "label":
assert bitcount == 0, "label isn't byte aligned"
map[line["label"]] = addr
elif type == "instr":
if len(line["instr"]) == 0:
continue
if segment == "data":
for part in line["instr"]:
bitcount += int(part[1])
if bitcount >= 8:
addr += bitcount // 8
bitcount = bitcount % 8
elif segment == "code":
assert (
bitcount == 0
), "instruction isn't byte aligned ({} bitcount left)".format(
8 - bitcount
)
assert addr % 2 == 0, "instruction isn't 2-byte aligned"
op = line["instr"][0]
instr_size = 0
if op[1] in "usirjb":
addr += 4
else:
raise ValueError("Unknown instruction format '{}'".format(op[1]))
else:
raise ValueError("unknown segment '{}'".format(segment))
for i, line in enumerate(queue, start=1):
try:
type = line["type"]
if type == "instr":
instr = []
for part in line[type]:
instr.append(observe(part, line["addr"], map))
line[type] = instr
yield subv.format(line)
elif type == "label":
yield "# {}".format(line["raw"])
else:
yield line["raw"]
except Exception as e:
msg = "failed to survey line"
msg = msg + "\n{}:{}: {}".format("(unknown)", i, subv.format(line))
msg = msg + "\nparsed as {}".format(subv.dump(line))
raise subv.SubVException(msg) from e
if __name__ == "__main__":
import sys
for line in survey(sys.stdin):
print(line)