X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=debug%2Fgdbserver.py;h=3d4533e1393960787ede1ac4c6067d74c5d757be;hb=610e0cb499a807287320fb13701cdee373a0a091;hp=88c565765c4bffe174b523c9b8a551f4b2b29c7c;hpb=6990284b8eab8d4e4f57f82ac8918913c5c63e97;p=riscv-tests.git

diff --git a/debug/gdbserver.py b/debug/gdbserver.py
index 88c5657..3d4533e 100755
--- a/debug/gdbserver.py
+++ b/debug/gdbserver.py
@@ -1,300 +1,700 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
-import os
-import sys
 import argparse
-import testlib
-import unittest
+import binascii
+import random
+import sys
 import tempfile
 import time
-import random
-import binascii
-
-class DeleteServer(unittest.TestCase):
-    def tearDown(self):
-        del self.server
-
-class MemoryTest(DeleteServer):
-    def setUp(self):
-        self.server = target.server()
-        self.gdb = testlib.Gdb()
-        self.gdb.command("target extended-remote localhost:%d" % self.server.port)
-
-    def test_32(self):
-        self.gdb.p("*((int*)0x%x) = 0x8675309" % target.ram)
-        self.gdb.p("*((int*)0x%x) = 0xdeadbeef" % (target.ram + 4))
-        self.assertEqual(self.gdb.p("*((int*)0x%x)" % target.ram), 0x8675309)
-        self.assertEqual(self.gdb.p("*((int*)0x%x)" % (target.ram + 4)), 0xdeadbeef)
-
-class InstantHaltTest(DeleteServer):
-    def setUp(self):
-        self.binary = target.compile("programs/debug.c")
-        self.server = target.server(self.binary, halted=True)
-        self.gdb = testlib.Gdb()
-        self.gdb.command("file %s" % self.binary)
-        self.gdb.command("target extended-remote localhost:%d" % self.server.port)
 
-    def test_instant_halt(self):
-        self.assertEqual(0x1000, self.gdb.p("$pc"))
-        # For some reason instret resets to 0.
-        self.assertLess(self.gdb.p("$instret"), 8)
-        self.gdb.command("stepi")
-        self.assertNotEqual(0x1000, self.gdb.p("$pc"))
+import targets
+import testlib
+from testlib import assertEqual, assertNotEqual, assertIn
+from testlib import assertGreater, assertTrue, assertRegexpMatches, assertLess
+from testlib import GdbTest
+
+MSTATUS_UIE = 0x00000001
+MSTATUS_SIE = 0x00000002
+MSTATUS_HIE = 0x00000004
+MSTATUS_MIE = 0x00000008
+MSTATUS_UPIE = 0x00000010
+MSTATUS_SPIE = 0x00000020
+MSTATUS_HPIE = 0x00000040
+MSTATUS_MPIE = 0x00000080
+MSTATUS_SPP = 0x00000100
+MSTATUS_HPP = 0x00000600
+MSTATUS_MPP = 0x00001800
+MSTATUS_FS = 0x00006000
+MSTATUS_XS = 0x00018000
+MSTATUS_MPRV = 0x00020000
+MSTATUS_PUM = 0x00040000
+MSTATUS_MXR = 0x00080000
+MSTATUS_VM = 0x1F000000
+MSTATUS32_SD = 0x80000000
+MSTATUS64_SD = 0x8000000000000000
+
+# pylint: disable=abstract-method
+
+def ihex_line(address, record_type, data):
+    assert len(data) < 128
+    line = ":%02X%04X%02X" % (len(data), address, record_type)
+    check = len(data)
+    check += address % 256
+    check += address >> 8
+    check += record_type
+    for char in data:
+        value = ord(char)
+        check += value
+        line += "%02X" % value
+    line += "%02X\n" % ((256-check)%256)
+    return line
+
+def ihex_parse(line):
+    assert line.startswith(":")
+    line = line[1:]
+    data_len = int(line[:2], 16)
+    address = int(line[2:6], 16)
+    record_type = int(line[6:8], 16)
+    data = ""
+    for i in range(data_len):
+        data += "%c" % int(line[8+2*i:10+2*i], 16)
+    return record_type, address, data
+
+def readable_binary_string(s):
+    return "".join("%02x" % ord(c) for c in s)
+
+class SimpleRegisterTest(GdbTest):
+    def check_reg(self, name):
+        a = random.randrange(1<<self.target.xlen)
+        b = random.randrange(1<<self.target.xlen)
+        self.gdb.p("$%s=0x%x" % (name, a))
+        self.gdb.stepi()
+        assertEqual(self.gdb.p("$%s" % name), a)
+        self.gdb.p("$%s=0x%x" % (name, b))
+        self.gdb.stepi()
+        assertEqual(self.gdb.p("$%s" % name), b)
 
-    def test_change_pc(self):
+    def setup(self):
+        # 0x13 is nop
+        self.gdb.command("p *((int*) 0x%x)=0x13" % self.target.ram)
+        self.gdb.command("p *((int*) 0x%x)=0x13" % (self.target.ram + 4))
+        self.gdb.command("p *((int*) 0x%x)=0x13" % (self.target.ram + 8))
+        self.gdb.p("$pc=0x%x" % self.target.ram)
+
+class SimpleS0Test(SimpleRegisterTest):
+    def test(self):
+        self.check_reg("s0")
+
+class SimpleS1Test(SimpleRegisterTest):
+    def test(self):
+        self.check_reg("s1")
+
+class SimpleT0Test(SimpleRegisterTest):
+    def test(self):
+        self.check_reg("t0")
+
+class SimpleT1Test(SimpleRegisterTest):
+    def test(self):
+        self.check_reg("t1")
+
+class SimpleF18Test(SimpleRegisterTest):
+    def check_reg(self, name):
+        a = random.random()
+        b = random.random()
+        self.gdb.p_raw("$%s=%f" % (name, a))
+        self.gdb.stepi()
+        assertLess(abs(float(self.gdb.p_raw("$%s" % name)) - a), .001)
+        self.gdb.p_raw("$%s=%f" % (name, b))
+        self.gdb.stepi()
+        assertLess(abs(float(self.gdb.p_raw("$%s" % name)) - b), .001)
+
+    def early_applicable(self):
+        return self.target.extensionSupported('F')
+
+    def test(self):
+        self.check_reg("f18")
+
+class SimpleMemoryTest(GdbTest):
+    def access_test(self, size, data_type):
+        assertEqual(self.gdb.p("sizeof(%s)" % data_type), size)
+        a = 0x86753095555aaaa & ((1<<(size*8))-1)
+        b = 0xdeadbeef12345678 & ((1<<(size*8))-1)
+        self.gdb.p("*((%s*)0x%x) = 0x%x" % (data_type, self.target.ram, a))
+        self.gdb.p("*((%s*)0x%x) = 0x%x" % (data_type, self.target.ram + size,
+            b))
+        assertEqual(self.gdb.p("*((%s*)0x%x)" % (data_type, self.target.ram)),
+                a)
+        assertEqual(self.gdb.p("*((%s*)0x%x)" % (
+            data_type, self.target.ram + size)), b)
+
+class MemTest8(SimpleMemoryTest):
+    def test(self):
+        self.access_test(1, 'char')
+
+class MemTest16(SimpleMemoryTest):
+    def test(self):
+        self.access_test(2, 'short')
+
+class MemTest32(SimpleMemoryTest):
+    def test(self):
+        self.access_test(4, 'int')
+
+class MemTest64(SimpleMemoryTest):
+    def test(self):
+        self.access_test(8, 'long long')
+
+class MemTestReadInvalid(SimpleMemoryTest):
+    def test(self):
+        # This test relies on 'gdb_report_data_abort enable' being executed in
+        # the openocd.cfg file.
+        try:
+            self.gdb.p("*((int*)0xdeadbeef)")
+            assert False, "Read should have failed."
+        except testlib.CannotAccess as e:
+            assertEqual(e.address, 0xdeadbeef)
+        self.gdb.p("*((int*)0x%x)" % self.target.ram)
+
+class MemTestWriteInvalid(SimpleMemoryTest):
+    def test(self):
+        # This test relies on 'gdb_report_data_abort enable' being executed in
+        # the openocd.cfg file.
+        try:
+            self.gdb.p("*((int*)0xdeadbeef)=8675309")
+            assert False, "Write should have failed."
+        except testlib.CannotAccess as e:
+            assertEqual(e.address, 0xdeadbeef)
+        self.gdb.p("*((int*)0x%x)=6874742" % self.target.ram)
+
+class MemTestBlock(GdbTest):
+    def test(self):
+        length = 1024
+        line_length = 16
+        a = tempfile.NamedTemporaryFile(suffix=".ihex")
+        data = ""
+        for i in range(length / line_length):
+            line_data = "".join(["%c" % random.randrange(256)
+                for _ in range(line_length)])
+            data += line_data
+            a.write(ihex_line(i * line_length, 0, line_data))
+        a.flush()
+
+        self.gdb.command("restore %s 0x%x" % (a.name, self.target.ram))
+        for offset in range(0, length, 19*4) + [length-4]:
+            value = self.gdb.p("*((int*)0x%x)" % (self.target.ram + offset))
+            written = ord(data[offset]) | \
+                    (ord(data[offset+1]) << 8) | \
+                    (ord(data[offset+2]) << 16) | \
+                    (ord(data[offset+3]) << 24)
+            assertEqual(value, written)
+
+        b = tempfile.NamedTemporaryFile(suffix=".ihex")
+        self.gdb.command("dump ihex memory %s 0x%x 0x%x" % (b.name,
+            self.target.ram, self.target.ram + length))
+        for line in b:
+            record_type, address, line_data = ihex_parse(line)
+            if record_type == 0:
+                assertEqual(readable_binary_string(line_data),
+                        readable_binary_string(
+                            data[address:address+len(line_data)]))
+
+class InstantHaltTest(GdbTest):
+    def test(self):
+        assertEqual(self.target.reset_vector, self.gdb.p("$pc"))
+        # mcycle and minstret have no defined reset value.
+        mstatus = self.gdb.p("$mstatus")
+        assertEqual(mstatus & (MSTATUS_MIE | MSTATUS_MPRV |
+            MSTATUS_VM), 0)
+
+class InstantChangePc(GdbTest):
+    def test(self):
         """Change the PC right as we come out of reset."""
         # 0x13 is nop
-        self.gdb.command("p *((int*) 0x80000000)=0x13")
-        self.gdb.command("p *((int*) 0x80000004)=0x13")
-        self.gdb.command("p *((int*) 0x80000008)=0x13")
-        self.gdb.command("p $pc=0x80000000")
-        self.gdb.command("stepi")
-        self.assertEqual(0x80000004, self.gdb.p("$pc"))
-        self.gdb.command("stepi")
-        self.assertEqual(0x80000008, self.gdb.p("$pc"))
-
-class DebugTest(DeleteServer):
-    def setUp(self):
-        self.binary = target.compile("programs/debug.c", "programs/checksum.c")
-        self.server = target.server()
-        self.gdb = testlib.Gdb()
-        self.gdb.command("file %s" % self.binary)
-        self.gdb.command("target extended-remote localhost:%d" % self.server.port)
-        self.gdb.load(self.binary)
+        self.gdb.command("p *((int*) 0x%x)=0x13" % self.target.ram)
+        self.gdb.command("p *((int*) 0x%x)=0x13" % (self.target.ram + 4))
+        self.gdb.command("p *((int*) 0x%x)=0x13" % (self.target.ram + 8))
+        self.gdb.p("$pc=0x%x" % self.target.ram)
+        self.gdb.stepi()
+        assertEqual((self.target.ram + 4), self.gdb.p("$pc"))
+        self.gdb.stepi()
+        assertEqual((self.target.ram + 8), self.gdb.p("$pc"))
+
+class DebugTest(GdbTest):
+    # Include malloc so that gdb can make function calls. I suspect this malloc
+    # will silently blow through the memory set aside for it, so be careful.
+    compile_args = ("programs/debug.c", "programs/checksum.c",
+            "programs/tiny-malloc.c", "-DDEFINE_MALLOC", "-DDEFINE_FREE")
+
+    def setup(self):
+        self.gdb.load()
         self.gdb.b("_exit")
 
-    def exit(self):
+    def exit(self, expected_result=0xc86455d4):
         output = self.gdb.c()
-        self.assertIn("Breakpoint", output)
-        self.assertIn("_exit", output)
-        self.assertEqual(self.gdb.p("status"), 0xc86455d4)
+        assertIn("Breakpoint", output)
+        assertIn("_exit", output)
+        assertEqual(self.gdb.p("status"), expected_result)
+
+class DebugCompareSections(DebugTest):
+    def test(self):
+        output = self.gdb.command("compare-sections")
+        matched = 0
+        for line in output.splitlines():
+            if line.startswith("Section"):
+                assert line.endswith("matched.")
+                matched += 1
+        assertGreater(matched, 1)
+
+class DebugFunctionCall(DebugTest):
+    def test(self):
+        self.gdb.b("main:start")
+        self.gdb.c()
+        assertEqual(self.gdb.p('fib(6)'), 8)
+        assertEqual(self.gdb.p('fib(7)'), 13)
+        self.exit()
+
+class DebugChangeString(DebugTest):
+    def test(self):
+        text = "This little piggy went to the market."
+        self.gdb.b("main:start")
+        self.gdb.c()
+        self.gdb.p('fox = "%s"' % text)
+        self.exit(0x43b497b8)
 
-    def test_turbostep(self):
+class DebugTurbostep(DebugTest):
+    def test(self):
         """Single step a bunch of times."""
-        self.gdb.command("p i=0");
+        self.gdb.b("main:start")
+        self.gdb.c()
+        self.gdb.command("p i=0")
         last_pc = None
+        advances = 0
+        jumps = 0
         for _ in range(100):
-            self.gdb.command("stepi")
-            pc = self.gdb.command("p $pc")
-            self.assertNotEqual(last_pc, pc)
+            self.gdb.stepi()
+            pc = self.gdb.p("$pc")
+            assertNotEqual(last_pc, pc)
+            if last_pc and pc > last_pc and pc - last_pc <= 4:
+                advances += 1
+            else:
+                jumps += 1
             last_pc = pc
+        # Some basic sanity that we're not running between breakpoints or
+        # something.
+        assertGreater(jumps, 10)
+        assertGreater(advances, 50)
 
-    def test_exit(self):
+class DebugExit(DebugTest):
+    def test(self):
         self.exit()
 
-    def test_breakpoint(self):
+class DebugSymbols(DebugTest):
+    def test(self):
+        self.gdb.b("main")
+        self.gdb.b("rot13")
+        output = self.gdb.c()
+        assertIn(", main ", output)
+        output = self.gdb.c()
+        assertIn(", rot13 ", output)
+
+class DebugBreakpoint(DebugTest):
+    def test(self):
         self.gdb.b("rot13")
         # The breakpoint should be hit exactly 2 times.
-        for i in range(2):
+        for _ in range(2):
             output = self.gdb.c()
-            self.assertIn("Breakpoint ", output)
+            self.gdb.p("$pc")
+            assertIn("Breakpoint ", output)
+            assertIn("rot13 ", output)
         self.exit()
 
-    def test_registers(self):
+class Hwbp1(DebugTest):
+    def test(self):
+        if self.target.instruction_hardware_breakpoint_count < 1:
+            return 'not_applicable'
+
+        self.gdb.hbreak("rot13")
+        # The breakpoint should be hit exactly 2 times.
+        for _ in range(2):
+            output = self.gdb.c()
+            self.gdb.p("$pc")
+            assertRegexpMatches(output, r"[bB]reakpoint")
+            assertIn("rot13 ", output)
+        self.exit()
+
+class Hwbp2(DebugTest):
+    def test(self):
+        if self.target.instruction_hardware_breakpoint_count < 2:
+            return 'not_applicable'
+
+        self.gdb.hbreak("main")
+        self.gdb.hbreak("rot13")
+        # We should hit 3 breakpoints.
+        for expected in ("main", "rot13", "rot13"):
+            output = self.gdb.c()
+            self.gdb.p("$pc")
+            assertRegexpMatches(output, r"[bB]reakpoint")
+            assertIn("%s " % expected, output)
+        self.exit()
+
+class TooManyHwbp(DebugTest):
+    def run(self):
+        for i in range(30):
+            self.gdb.hbreak("*rot13 + %d" % (i * 4))
+
+        output = self.gdb.c()
+        assertIn("Cannot insert hardware breakpoint", output)
+        # Clean up, otherwise the hardware breakpoints stay set and future
+        # tests may fail.
+        self.gdb.command("D")
+
+class Registers(DebugTest):
+    def test(self):
+        # Get to a point in the code where some registers have actually been
+        # used.
         self.gdb.b("rot13")
         self.gdb.c()
+        self.gdb.c()
         # Try both forms to test gdb.
         for cmd in ("info all-registers", "info registers all"):
             output = self.gdb.command(cmd)
-            self.assertNotIn("Could not", output)
             for reg in ('zero', 'ra', 'sp', 'gp', 'tp'):
-                self.assertIn(reg, output)
+                assertIn(reg, output)
+
+        #TODO
         # mcpuid is one of the few registers that should have the high bit set
         # (for rv64).
         # Leave this commented out until gdb and spike agree on the encoding of
         # mcpuid (which is going to be renamed to misa in any case).
-        #self.assertRegexpMatches(output, ".*mcpuid *0x80")
+        #assertRegexpMatches(output, ".*mcpuid *0x80")
 
+        #TODO:
         # The instret register should always be changing.
-        last_instret = None
-        for _ in range(5):
-            instret = self.gdb.p("$instret")
-            self.assertNotEqual(instret, last_instret)
-            last_instret = instret
-            self.gdb.command("stepi")
+        #last_instret = None
+        #for _ in range(5):
+        #    instret = self.gdb.p("$instret")
+        #    assertNotEqual(instret, last_instret)
+        #    last_instret = instret
+        #    self.gdb.stepi()
 
         self.exit()
 
-    def test_interrupt(self):
-        """Sending gdb ^C while the program is running should cause it to halt."""
+class UserInterrupt(DebugTest):
+    def test(self):
+        """Sending gdb ^C while the program is running should cause it to
+        halt."""
         self.gdb.b("main:start")
         self.gdb.c()
-        self.gdb.command("p i=123");
+        self.gdb.p("i=123")
         self.gdb.c(wait=False)
-        time.sleep(0.1)
+        time.sleep(0.5)
         output = self.gdb.interrupt()
         assert "main" in output
-        self.assertGreater(self.gdb.p("j"), 10)
-        self.gdb.p("i=0");
+        assertGreater(self.gdb.p("j"), 10)
+        self.gdb.p("i=0")
         self.exit()
 
-class RegsTest(DeleteServer):
-    def setUp(self):
-        self.binary = target.compile("programs/regs.S")
-        self.server = target.server()
-        self.gdb = testlib.Gdb()
-        self.gdb.command("file %s" % self.binary)
-        self.gdb.command("target extended-remote localhost:%d" % self.server.port)
-        self.gdb.command("load")
-
-    def test_write_gprs(self):
-        # Note a0 is missing from this list since it's used to hold the
-        # address.
-        regs = ("ra", "sp", "gp", "tp", "t0", "t1", "t2", "fp", "s1",
-                "a1", "a2", "a3", "a4", "a5", "a6", "a7", "s2", "s3", "s4",
-                "s5", "s6", "s7", "s8", "s9", "s10", "s11", "t3", "t4", "t5",
-                "t6")
-
-        self.gdb.command("p $pc=write_regs")
+class StepTest(GdbTest):
+    compile_args = ("programs/step.S", )
+
+    def setup(self):
+        self.gdb.load()
+        self.gdb.b("main")
+        self.gdb.c()
+
+    def test(self):
+        main_address = self.gdb.p("$pc")
+        if self.target.extensionSupported("c"):
+            sequence = (4, 8, 0xc, 0xe, 0x14, 0x18, 0x22, 0x1c, 0x24, 0x24)
+        else:
+            sequence = (4, 8, 0xc, 0x10, 0x18, 0x1c, 0x28, 0x20, 0x2c, 0x2c)
+        for expected in sequence:
+            self.gdb.stepi()
+            pc = self.gdb.p("$pc")
+            assertEqual("%x" % (pc - main_address), "%x" % expected)
+
+class TriggerTest(GdbTest):
+    compile_args = ("programs/trigger.S", )
+    def setup(self):
+        self.gdb.load()
+        self.gdb.b("_exit")
+        self.gdb.b("main")
+        self.gdb.c()
+
+    def exit(self):
+        output = self.gdb.c()
+        assertIn("Breakpoint", output)
+        assertIn("_exit", output)
+
+class TriggerExecuteInstant(TriggerTest):
+    """Test an execute breakpoint on the first instruction executed out of
+    debug mode."""
+    def test(self):
+        main_address = self.gdb.p("$pc")
+        self.gdb.command("hbreak *0x%x" % (main_address + 4))
+        self.gdb.c()
+        assertEqual(self.gdb.p("$pc"), main_address+4)
+
+class TriggerLoadAddress(TriggerTest):
+    def test(self):
+        self.gdb.command("rwatch *((&data)+1)")
+        output = self.gdb.c()
+        assertIn("read_loop", output)
+        assertEqual(self.gdb.p("$a0"),
+                self.gdb.p("(&data)+1"))
+        self.exit()
+
+class TriggerLoadAddressInstant(TriggerTest):
+    """Test a load address breakpoint on the first instruction executed out of
+    debug mode."""
+    def test(self):
+        self.gdb.command("b just_before_read_loop")
+        self.gdb.c()
+        read_loop = self.gdb.p("&read_loop")
+        self.gdb.command("rwatch data")
+        self.gdb.c()
+        # Accept hitting the breakpoint before or after the load instruction.
+        assertIn(self.gdb.p("$pc"), [read_loop, read_loop + 4])
+        assertEqual(self.gdb.p("$a0"), self.gdb.p("&data"))
+
+class TriggerStoreAddress(TriggerTest):
+    def test(self):
+        self.gdb.command("watch *((&data)+3)")
+        output = self.gdb.c()
+        assertIn("write_loop", output)
+        assertEqual(self.gdb.p("$a0"),
+                self.gdb.p("(&data)+3"))
+        self.exit()
+
+class TriggerStoreAddressInstant(TriggerTest):
+    def test(self):
+        """Test a store address breakpoint on the first instruction executed out
+        of debug mode."""
+        self.gdb.command("b just_before_write_loop")
+        self.gdb.c()
+        write_loop = self.gdb.p("&write_loop")
+        self.gdb.command("watch data")
+        self.gdb.c()
+        # Accept hitting the breakpoint before or after the store instruction.
+        assertIn(self.gdb.p("$pc"), [write_loop, write_loop + 4])
+        assertEqual(self.gdb.p("$a0"), self.gdb.p("&data"))
+
+class TriggerDmode(TriggerTest):
+    def check_triggers(self, tdata1_lsbs, tdata2):
+        dmode = 1 << (self.target.xlen-5)
+
+        triggers = []
+
+        if self.target.xlen == 32:
+            xlen_type = 'int'
+        elif self.target.xlen == 64:
+            xlen_type = 'long long'
+        else:
+            raise NotImplementedError
+
+        dmode_count = 0
+        i = 0
+        for i in range(16):
+            tdata1 = self.gdb.p("((%s *)&data)[%d]" % (xlen_type, 2*i))
+            if tdata1 == 0:
+                break
+            tdata2 = self.gdb.p("((%s *)&data)[%d]" % (xlen_type, 2*i+1))
+
+            if tdata1 & dmode:
+                dmode_count += 1
+            else:
+                assertEqual(tdata1 & 0xffff, tdata1_lsbs)
+                assertEqual(tdata2, tdata2)
+
+        assertGreater(i, 1)
+        assertEqual(dmode_count, 1)
+
+        return triggers
+
+    def test(self):
+        self.gdb.command("hbreak write_load_trigger")
+        self.gdb.b("clear_triggers")
+        self.gdb.p("$pc=write_store_trigger")
+        output = self.gdb.c()
+        assertIn("write_load_trigger", output)
+        self.check_triggers((1<<6) | (1<<1), 0xdeadbee0)
+        output = self.gdb.c()
+        assertIn("clear_triggers", output)
+        self.check_triggers((1<<6) | (1<<0), 0xfeedac00)
+
+class RegsTest(GdbTest):
+    compile_args = ("programs/regs.S", )
+    def setup(self):
+        self.gdb.load()
+        self.gdb.b("main")
+        self.gdb.b("handle_trap")
+        self.gdb.c()
+
+class WriteGprs(RegsTest):
+    def test(self):
+        regs = [("x%d" % n) for n in range(2, 32)]
+
+        self.gdb.p("$pc=write_regs")
         for i, r in enumerate(regs):
-            self.gdb.command("p $%s=%d" % (r, (0xdeadbeef<<i)+17))
-        self.gdb.command("p $a0=data")
+            self.gdb.p("$%s=%d" % (r, (0xdeadbeef<<i)+17))
+        self.gdb.p("$x1=data")
         self.gdb.command("b all_done")
-        output = self.gdb.command("c")
-        self.assertIn("Breakpoint 1", output)
+        output = self.gdb.c()
+        assertIn("Breakpoint ", output)
 
         # Just to get this data in the log.
         self.gdb.command("x/30gx data")
         self.gdb.command("info registers")
         for n in range(len(regs)):
-            self.assertEqual(self.gdb.x("data+%d" % (8*n), 'g'),
-                    (0xdeadbeef<<n)+17)
+            assertEqual(self.gdb.x("data+%d" % (8*n), 'g'),
+                    ((0xdeadbeef<<n)+17) & ((1<<self.target.xlen)-1))
 
-    def test_write_csrs(self):
+class WriteCsrs(RegsTest):
+    def test(self):
         # As much a test of gdb as of the simulator.
         self.gdb.p("$mscratch=0")
         self.gdb.stepi()
-        self.assertEqual(self.gdb.p("$mscratch"), 0)
+        assertEqual(self.gdb.p("$mscratch"), 0)
         self.gdb.p("$mscratch=123")
         self.gdb.stepi()
-        self.assertEqual(self.gdb.p("$mscratch"), 123)
+        assertEqual(self.gdb.p("$mscratch"), 123)
 
-        self.gdb.command("p $fflags=9")
-        self.gdb.command("p $pc=write_regs")
-        self.gdb.command("p $a0=data")
+        self.gdb.p("$pc=write_regs")
+        self.gdb.p("$x1=data")
         self.gdb.command("b all_done")
         self.gdb.command("c")
 
-        self.assertEqual(9, self.gdb.p("$fflags"))
-        self.assertEqual(9, self.gdb.p("$x1"))
-        self.assertEqual(9, self.gdb.p("$csr1"))
-
-class DownloadTest(DeleteServer):
-    def setUp(self):
-        length = 2**20
-        fd = file("data.c", "w")
-# extern uint8_t *data;
-# extern uint32_t length;
-# 
-# uint32_t main()
-#{
-#  /* Compute a simple checksum. */
-#  return crc32a(data, length);
-#}
-        fd.write("#include <stdint.h>\n")
-        fd.write("uint32_t length = %d;\n" % length)
-        fd.write("uint8_t d[%d] = {\n" % length)
+        assertEqual(123, self.gdb.p("$mscratch"))
+        assertEqual(123, self.gdb.p("$x1"))
+        assertEqual(123, self.gdb.p("$csr832"))
+
+class DownloadTest(GdbTest):
+    def setup(self):
+        # pylint: disable=attribute-defined-outside-init
+        length = min(2**20, self.target.ram_size - 2048)
+        download_c = tempfile.NamedTemporaryFile(prefix="download_",
+                suffix=".c")
+        download_c.write("#include <stdint.h>\n")
+        download_c.write(
+                "unsigned int crc32a(uint8_t *message, unsigned int size);\n")
+        download_c.write("uint32_t length = %d;\n" % length)
+        download_c.write("uint8_t d[%d] = {\n" % length)
         self.crc = 0
         for i in range(length / 16):
-            fd.write("  /* 0x%04x */ " % (i * 16));
+            download_c.write("  /* 0x%04x */ " % (i * 16))
             for _ in range(16):
                 value = random.randrange(1<<8)
-                fd.write("%d, " % value)
+                download_c.write("%d, " % value)
                 self.crc = binascii.crc32("%c" % value, self.crc)
-            fd.write("\n");
-        fd.write("};\n");
-        fd.write("uint8_t *data = &d[0];\n");
-        fd.close()
-
-        self.binary = target.compile("checksum.c", "data.c", "start.S",
-                "-mcmodel=medany",
-                "-T", "standalone.lds",
-                "-nostartfiles"
-                )
-        self.server = target.server(None, halted=True)
-        self.gdb = testlib.Gdb()
+            download_c.write("\n")
+        download_c.write("};\n")
+        download_c.write("uint8_t *data = &d[0];\n")
+        download_c.write("uint32_t main() { return crc32a(data, length); }\n")
+        download_c.flush()
+
+        if self.crc < 0:
+            self.crc += 2**32
+
+        self.binary = self.target.compile(download_c.name,
+                "programs/checksum.c")
         self.gdb.command("file %s" % self.binary)
-        self.gdb.command("target extended-remote localhost:%d" % self.server.port)
 
-    def test_download(self):
-        output = self.gdb.command("load")
-        self.assertNotIn("failed", output)
-        self.assertIn("Transfer rate", output)
-        self.gdb.command("b done")
+    def test(self):
+        self.gdb.load()
+        self.gdb.command("b _exit")
         self.gdb.c()
-        result = self.gdb.p("$a0")
-        self.assertEqual(self.crc, result)
-
-class MprvTest(DeleteServer):
-    def setUp(self):
-        self.binary = target.compile("mprv.S", "-T", "standalone.lds",
-                "-nostartfiles")
-        self.server = target.server(None, halted=True)
-        self.gdb = testlib.Gdb()
-        self.gdb.command("file %s" % self.binary)
-        self.gdb.command("target extended-remote localhost:%d" % self.server.port)
-        self.gdb.command("load")
+        assertEqual(self.gdb.p("status"), self.crc)
+
+class MprvTest(GdbTest):
+    compile_args = ("programs/mprv.S", )
+    def setup(self):
+        self.gdb.load()
 
-    def test_mprv(self):
+    def test(self):
         """Test that the debugger can access memory when MPRV is set."""
         self.gdb.c(wait=False)
+        time.sleep(0.5)
         self.gdb.interrupt()
         output = self.gdb.command("p/x *(int*)(((char*)&data)-0x80000000)")
-        self.assertIn("0xbead", output)
-
-class Target(object):
-    def server(self):
-        raise NotImplementedError
-
-    def compile(self, *sources):
-        return testlib.compile(sources +
-                ("targets/%s/entry.S" % self.name, "programs/init.c",
-                    "-I", "../env",
-                    "-T", "targets/%s/link.lds" % self.name,
-                    "-nostartfiles",
-                    "-mcmodel=medany"), xlen=self.xlen)
-
-class SpikeTarget(Target):
-    name = "spike"
-    xlen = 64
-    ram = 0x80010000
-
-    def server(self):
-        return testlib.Spike(parsed.cmd, halted=True)
-
-class MicroSemiTarget(Target):
-    name = "m2gl_m2s"
-    xlen = 32
-    ram = 0x80000000
-
-    def server(self):
-        return testlib.Openocd(cmd=parsed.cmd,
-                config="targets/%s/openocd.cfg" % self.name)
-
-targets = [
-        SpikeTarget,
-        MicroSemiTarget
-        ]
+        assertIn("0xbead", output)
+
+class PrivTest(GdbTest):
+    compile_args = ("programs/priv.S", )
+    def setup(self):
+        # pylint: disable=attribute-defined-outside-init
+        self.gdb.load()
+
+        misa = self.target.misa
+        self.supported = set()
+        if misa & (1<<20):
+            self.supported.add(0)
+        if misa & (1<<18):
+            self.supported.add(1)
+        if misa & (1<<7):
+            self.supported.add(2)
+        self.supported.add(3)
+
+class PrivRw(PrivTest):
+    def test(self):
+        """Test reading/writing priv."""
+        for privilege in range(4):
+            self.gdb.p("$priv=%d" % privilege)
+            self.gdb.stepi()
+            actual = self.gdb.p("$priv")
+            assertIn(actual, self.supported)
+            if privilege in self.supported:
+                assertEqual(actual, privilege)
+
+class PrivChange(PrivTest):
+    def test(self):
+        """Test that the core's privilege level actually changes."""
+
+        if 0 not in self.supported:
+            return 'not_applicable'
+
+        self.gdb.b("main")
+        self.gdb.c()
+
+        # Machine mode
+        self.gdb.p("$priv=3")
+        main_address = self.gdb.p("$pc")
+        self.gdb.stepi()
+        assertEqual("%x" % self.gdb.p("$pc"), "%x" % (main_address+4))
+
+        # User mode
+        self.gdb.p("$priv=0")
+        self.gdb.stepi()
+        # Should have taken an exception, so be nowhere near main.
+        pc = self.gdb.p("$pc")
+        assertTrue(pc < main_address or pc > main_address + 0x100)
 
+parsed = None
 def main():
-    parser = argparse.ArgumentParser()
-    group = parser.add_mutually_exclusive_group(required=True)
-    for t in targets:
-        group.add_argument("--%s" % t.name, action="store_const", const=t,
-                dest="target")
-    parser.add_argument("--cmd",
-            help="The command to use to start the debug server.")
-    parser.add_argument("unittest", nargs="*")
-    global parsed
+    parser = argparse.ArgumentParser(
+            description="Test that gdb can talk to a RISC-V target.",
+            epilog="""
+            Example command line from the real world:
+            Run all RegsTest cases against a physical FPGA, with custom openocd command:
+            ./gdbserver.py --freedom-e300 --cmd "$HOME/SiFive/openocd/src/openocd -s $HOME/SiFive/openocd/tcl -d" Simple
+            """)
+    targets.add_target_options(parser)
+
+    testlib.add_test_run_options(parser)
+
+    # TODO: remove global
+    global parsed   # pylint: disable=global-statement
     parsed = parser.parse_args()
 
-    global target
-    target = parsed.target()
-    unittest.main(argv=[sys.argv[0]] + parsed.unittest)
+    target = parsed.target(parsed.cmd, parsed.run, parsed.isolate)
+    if parsed.xlen:
+        target.xlen = parsed.xlen
+
+    module = sys.modules[__name__]
+
+    return testlib.run_all_tests(module, target, parsed)
 
 # TROUBLESHOOTING TIPS
 # If a particular test fails, run just that one test, eg.:
-# ./tests/gdbserver.py MprvTest.test_mprv
+# ./gdbserver.py MprvTest.test_mprv
 # Then inspect gdb.log and spike.log to see what happened in more detail.
 
 if __name__ == '__main__':