From 425a78ec1bff140c17d628768495142170c46368 Mon Sep 17 00:00:00 2001
From: Rozlette <Uberpanzermensch@gmail.com>
Date: Sun, 21 Jan 2018 10:53:09 -0600
Subject: [PATCH] gdbstub: Update registers and sizes for aarch64
This gets gdbstub working at least to the point where clients can
communicate with it.
What works:
- Reading/writing GPRegs
- Reading/writing memory
- Interrupting the emulated program and continuing
What does NOT work:
- Breakpoints. Sizes have been updated to u64, but support will need to be
added in the interpreter for them to work.
- VRegs. Mostly because my gdb was having issues with 128-bit regs for
some reason. However, the current u128 representation is a bit
awkward to use and should probably be updated first.
---
src/core/gdbstub/gdbstub.cpp | 266 ++++++++++++++++++++---------------
1 file changed, 154 insertions(+), 112 deletions(-)
diff --git a/src/core/gdbstub/gdbstub.cpp b/src/core/gdbstub/gdbstub.cpp
index 2f3ccb689..2405da0c6 100644
--- a/src/core/gdbstub/gdbstub.cpp
+++ b/src/core/gdbstub/gdbstub.cpp
@@ -57,9 +57,10 @@ const u32 SIGTERM = 15;
const u32 MSG_WAITALL = 8;
#endif
-const u32 R15_REGISTER = 15;
-const u32 CPSR_REGISTER = 25;
-const u32 FPSCR_REGISTER = 58;
+const u32 X30_REGISTER = 30;
+const u32 SP_REGISTER = 31;
+const u32 PC_REGISTER = 32;
+const u32 CPSR_REGISTER = 33;
// For sample XML files see the GDB source /gdb/features
// GDB also wants the l character at the start
@@ -68,48 +69,62 @@ static const char* target_xml =
R"(l<?xml version="1.0"?>
<!DOCTYPE target SYSTEM "gdb-target.dtd">
<target version="1.0">
- <feature name="org.gnu.gdb.arm.core">
- <reg name="r0" bitsize="32"/>
- <reg name="r1" bitsize="32"/>
- <reg name="r2" bitsize="32"/>
- <reg name="r3" bitsize="32"/>
- <reg name="r4" bitsize="32"/>
- <reg name="r5" bitsize="32"/>
- <reg name="r6" bitsize="32"/>
- <reg name="r7" bitsize="32"/>
- <reg name="r8" bitsize="32"/>
- <reg name="r9" bitsize="32"/>
- <reg name="r10" bitsize="32"/>
- <reg name="r11" bitsize="32"/>
- <reg name="r12" bitsize="32"/>
- <reg name="sp" bitsize="32" type="data_ptr"/>
- <reg name="lr" bitsize="32"/>
- <reg name="pc" bitsize="32" type="code_ptr"/>
+ <feature name="org.gnu.gdb.aarch64.core">
+ <reg name="x0" bitsize="64"/>
+ <reg name="x1" bitsize="64"/>
+ <reg name="x2" bitsize="64"/>
+ <reg name="x3" bitsize="64"/>
+ <reg name="x4" bitsize="64"/>
+ <reg name="x5" bitsize="64"/>
+ <reg name="x6" bitsize="64"/>
+ <reg name="x7" bitsize="64"/>
+ <reg name="x8" bitsize="64"/>
+ <reg name="x9" bitsize="64"/>
+ <reg name="x10" bitsize="64"/>
+ <reg name="x11" bitsize="64"/>
+ <reg name="x12" bitsize="64"/>
+ <reg name="x13" bitsize="64"/>
+ <reg name="x14" bitsize="64"/>
+ <reg name="x15" bitsize="64"/>
+ <reg name="x16" bitsize="64"/>
+ <reg name="x17" bitsize="64"/>
+ <reg name="x18" bitsize="64"/>
+ <reg name="x19" bitsize="64"/>
+ <reg name="x20" bitsize="64"/>
+ <reg name="x21" bitsize="64"/>
+ <reg name="x22" bitsize="64"/>
+ <reg name="x23" bitsize="64"/>
+ <reg name="x24" bitsize="64"/>
+ <reg name="x25" bitsize="64"/>
+ <reg name="x26" bitsize="64"/>
+ <reg name="x27" bitsize="64"/>
+ <reg name="x28" bitsize="64"/>
+ <reg name="x29" bitsize="64"/>
+ <reg name="x30" bitsize="64"/>
+ <reg name="sp" bitsize="64" type="data_ptr"/>
- <!-- The CPSR is register 25, rather than register 16, because
- the FPA registers historically were placed between the PC
- and the CPSR in the "g" packet. -->
+ <reg name="pc" bitsize="64" type="code_ptr"/>
- <reg name="cpsr" bitsize="32" regnum="25"/>
- </feature>
- <feature name="org.gnu.gdb.arm.vfp">
- <reg name="d0" bitsize="64" type="float"/>
- <reg name="d1" bitsize="64" type="float"/>
- <reg name="d2" bitsize="64" type="float"/>
- <reg name="d3" bitsize="64" type="float"/>
- <reg name="d4" bitsize="64" type="float"/>
- <reg name="d5" bitsize="64" type="float"/>
- <reg name="d6" bitsize="64" type="float"/>
- <reg name="d7" bitsize="64" type="float"/>
- <reg name="d8" bitsize="64" type="float"/>
- <reg name="d9" bitsize="64" type="float"/>
- <reg name="d10" bitsize="64" type="float"/>
- <reg name="d11" bitsize="64" type="float"/>
- <reg name="d12" bitsize="64" type="float"/>
- <reg name="d13" bitsize="64" type="float"/>
- <reg name="d14" bitsize="64" type="float"/>
- <reg name="d15" bitsize="64" type="float"/>
- <reg name="fpscr" bitsize="32" type="int" group="float"/>
+ <flags id="cpsr_flags" size="4">
+ <field name="SP" start="0" end="0"/>
+ <field name="" start="1" end="1"/>
+ <field name="EL" start="2" end="3"/>
+ <field name="nRW" start="4" end="4"/>
+ <field name="" start="5" end="5"/>
+ <field name="F" start="6" end="6"/>
+ <field name="I" start="7" end="7"/>
+ <field name="A" start="8" end="8"/>
+ <field name="D" start="9" end="9"/>
+
+ <field name="IL" start="20" end="20"/>
+ <field name="SS" start="21" end="21"/>
+
+ <field name="V" start="28" end="28"/>
+ <field name="C" start="29" end="29"/>
+ <field name="Z" start="30" end="30"/>
+ <field name="N" start="31" end="31"/>
+ </flags>
+ <reg name="cpsr" bitsize="32" type="cpsr_flags"/>
</feature>
</target>
)";
@@ -143,12 +158,12 @@ WSADATA InitData;
struct Breakpoint {
bool active;
PAddr addr;
- u32 len;
+ u64 len;
};
-static std::map<u32, Breakpoint> breakpoints_execute;
-static std::map<u32, Breakpoint> breakpoints_read;
-static std::map<u32, Breakpoint> breakpoints_write;
+static std::map<u64, Breakpoint> breakpoints_execute;
+static std::map<u64, Breakpoint> breakpoints_read;
+static std::map<u64, Breakpoint> breakpoints_write;
/**
* Turns hex string character into the equivalent byte.
@@ -197,6 +212,21 @@ static u32 HexToInt(const u8* src, size_t len) {
return output;
}
+/**
+ * Converts input hex string characters into an array of equivalent of u8 bytes.
+ *
+ * @param src Pointer to array of output hex string characters.
+ * @param len Length of src array.
+ */
+static u64 HexToLong(const u8* src, size_t len) {
+ u64 output = 0;
+ while (len-- > 0) {
+ output = (output << 4) | HexCharToValue(src[0]);
+ src++;
+ }
+ return output;
+}
+
/**
* Converts input array of u8 bytes into their equivalent hex string characters.
*
@@ -234,8 +264,21 @@ static void GdbHexToMem(u8* dest, const u8* src, size_t len) {
*/
static void IntToGdbHex(u8* dest, u32 v) {
for (int i = 0; i < 8; i += 2) {
- dest[i + 1] = NibbleToHex(v >> (4 * i));
- dest[i] = NibbleToHex(v >> (4 * (i + 1)));
+ dest[i + 1] = NibbleToHex(static_cast<u8>(v >> (4 * i)));
+ dest[i] = NibbleToHex(static_cast<u8>(v >> (4 * (i + 1))));
+ }
+}
+
+/**
+ * Convert a u64 into a gdb-formatted hex string.
+ *
+ * @param dest Pointer to buffer to store output hex string characters.
+ * @param v Value to convert.
+ */
+static void LongToGdbHex(u8* dest, u64 v) {
+ for (int i = 0; i < 16; i += 2) {
+ dest[i + 1] = NibbleToHex(static_cast<u8>(v >> (4 * i)));
+ dest[i] = NibbleToHex(static_cast<u8>(v >> (4 * (i + 1))));
}
}
@@ -255,6 +298,22 @@ static u32 GdbHexToInt(const u8* src) {
return output;
}
+/**
+ * Convert a gdb-formatted hex string into a u64.
+ *
+ * @param src Pointer to hex string.
+ */
+static u64 GdbHexToLong(const u8* src) {
+ u64 output = 0;
+
+ for (int i = 0; i < 16; i += 2) {
+ output = (output << 4) | HexCharToValue(src[15 - i - 1]);
+ output = (output << 4) | HexCharToValue(src[15 - i]);
+ }
+
+ return output;
+}
+
/// Read a byte from the gdb client.
static u8 ReadByte() {
u8 c;
@@ -277,7 +336,7 @@ static u8 CalculateChecksum(const u8* buffer, size_t length) {
*
* @param type Type of breakpoint list.
*/
-static std::map<u32, Breakpoint>& GetBreakpointList(BreakpointType type) {
+static std::map<u64, Breakpoint>& GetBreakpointList(BreakpointType type) {
switch (type) {
case BreakpointType::Execute:
return breakpoints_execute;
@@ -297,19 +356,19 @@ static std::map<u32, Breakpoint>& GetBreakpointList(BreakpointType type) {
* @param addr Address of breakpoint.
*/
static void RemoveBreakpoint(BreakpointType type, PAddr addr) {
- std::map<u32, Breakpoint>& p = GetBreakpointList(type);
+ std::map<u64, Breakpoint>& p = GetBreakpointList(type);
- auto bp = p.find(static_cast<u32>(addr));
+ auto bp = p.find(static_cast<u64>(addr));
if (bp != p.end()) {
LOG_DEBUG(Debug_GDBStub, "gdb: removed a breakpoint: %08x bytes at %08x of type %d\n",
bp->second.len, bp->second.addr, type);
- p.erase(static_cast<u32>(addr));
+ p.erase(static_cast<u64>(addr));
}
}
BreakpointAddress GetNextBreakpointFromAddress(PAddr addr, BreakpointType type) {
- std::map<u32, Breakpoint>& p = GetBreakpointList(type);
- auto next_breakpoint = p.lower_bound(static_cast<u32>(addr));
+ std::map<u64, Breakpoint>& p = GetBreakpointList(type);
+ auto next_breakpoint = p.lower_bound(static_cast<u64>(addr));
BreakpointAddress breakpoint;
if (next_breakpoint != p.end()) {
@@ -328,11 +387,11 @@ bool CheckBreakpoint(PAddr addr, BreakpointType type) {
return false;
}
- std::map<u32, Breakpoint>& p = GetBreakpointList(type);
+ std::map<u64, Breakpoint>& p = GetBreakpointList(type);
- auto bp = p.find(static_cast<u32>(addr));
+ auto bp = p.find(static_cast<u64>(addr));
if (bp != p.end()) {
- u32 len = bp->second.len;
+ u64 len = bp->second.len;
// IDA Pro defaults to 4-byte breakpoints for all non-hardware breakpoints
// no matter if it's a 4-byte or 2-byte instruction. When you execute a
@@ -419,7 +478,7 @@ static void HandleQuery() {
SendReply("T0");
} else if (strncmp(query, "Supported", strlen("Supported")) == 0) {
// PacketSize needs to be large enough for target xml
- SendReply("PacketSize=800;qXfer:features:read+");
+ SendReply("PacketSize=2000;qXfer:features:read+");
} else if (strncmp(query, "Xfer:features:read:target.xml:",
strlen("Xfer:features:read:target.xml:")) == 0) {
SendReply(target_xml);
@@ -450,10 +509,7 @@ static void SendSignal(u32 signal) {
latest_signal = signal;
- std::string buffer =
- Common::StringFromFormat("T%02x%02x:%08x;%02x:%08x;", latest_signal, 15,
- htonl(static_cast<u_long>(Core::CPU().GetPC())), 13,
- htonl(static_cast<u_long>(Core::CPU().GetReg(13))));
+ std::string buffer = Common::StringFromFormat("T%02x", latest_signal);
LOG_DEBUG(Debug_GDBStub, "Response: %s", buffer.c_str());
SendReply(buffer.c_str());
}
@@ -539,16 +595,12 @@ static void ReadRegister() {
id |= HexCharToValue(command_buffer[2]);
}
- if (id <= R15_REGISTER) {
- IntToGdbHex(reply, static_cast<u32>(Core::CPU().GetReg(static_cast<u64>(id))));
+ if (id <= SP_REGISTER) {
+ LongToGdbHex(reply, Core::CPU().GetReg(static_cast<int>(id)));
+ } else if (id == PC_REGISTER) {
+ LongToGdbHex(reply, Core::CPU().GetPC());
} else if (id == CPSR_REGISTER) {
IntToGdbHex(reply, Core::CPU().GetCPSR());
- } else if (id > CPSR_REGISTER && id < FPSCR_REGISTER) {
- IntToGdbHex(reply, Core::CPU().GetVFPReg(
- id - CPSR_REGISTER -
- 1)); // VFP registers should start at 26, so one after CSPR_REGISTER
- } else if (id == FPSCR_REGISTER) {
- UNIMPLEMENTED();
} else {
return SendReply("E01");
}
@@ -563,21 +615,19 @@ static void ReadRegisters() {
u8* bufptr = buffer;
- for (int reg = 0; reg <= R15_REGISTER; reg++) {
- IntToGdbHex(bufptr + reg * CHAR_BIT, static_cast<u32>(Core::CPU().GetReg(reg)));
+ for (int reg = 0; reg <= SP_REGISTER; reg++) {
+ LongToGdbHex(bufptr + reg * 16, Core::CPU().GetReg(reg));
}
- bufptr += (16 * CHAR_BIT);
+ bufptr += (32 * 16);
+
+ LongToGdbHex(bufptr, Core::CPU().GetPC());
+
+ bufptr += 16;
IntToGdbHex(bufptr, Core::CPU().GetCPSR());
- bufptr += CHAR_BIT;
-
- for (int reg = 0; reg <= 31; reg++) {
- IntToGdbHex(bufptr + reg * CHAR_BIT, Core::CPU().GetVFPReg(reg));
- }
-
- bufptr += (32 * CHAR_BIT);
+ bufptr += 8;
SendReply(reinterpret_cast<char*>(buffer));
}
@@ -593,14 +643,12 @@ static void WriteRegister() {
id |= HexCharToValue(command_buffer[2]);
}
- if (id <= R15_REGISTER) {
- Core::CPU().SetReg(id, GdbHexToInt(buffer_ptr));
+ if (id <= SP_REGISTER) {
+ Core::CPU().SetReg(id, GdbHexToLong(buffer_ptr));
+ } else if (id == PC_REGISTER) {
+ Core::CPU().SetPC(GdbHexToLong(buffer_ptr));
} else if (id == CPSR_REGISTER) {
Core::CPU().SetCPSR(GdbHexToInt(buffer_ptr));
- } else if (id > CPSR_REGISTER && id < FPSCR_REGISTER) {
- Core::CPU().SetVFPReg(id - CPSR_REGISTER - 1, GdbHexToInt(buffer_ptr));
- } else if (id == FPSCR_REGISTER) {
- UNIMPLEMENTED();
} else {
return SendReply("E01");
}
@@ -615,20 +663,14 @@ static void WriteRegisters() {
if (command_buffer[0] != 'G')
return SendReply("E01");
- for (int i = 0, reg = 0; reg <= FPSCR_REGISTER; i++, reg++) {
- if (reg <= R15_REGISTER) {
- Core::CPU().SetReg(reg, GdbHexToInt(buffer_ptr + i * CHAR_BIT));
+ for (int i = 0, reg = 0; reg <= CPSR_REGISTER; i++, reg++) {
+ if (reg <= SP_REGISTER) {
+ Core::CPU().SetReg(reg, GdbHexToLong(buffer_ptr + i * 16));
+ } else if (reg == PC_REGISTER) {
+ Core::CPU().SetPC(GdbHexToLong(buffer_ptr + i * 16));
} else if (reg == CPSR_REGISTER) {
- Core::CPU().SetCPSR(GdbHexToInt(buffer_ptr + i * CHAR_BIT));
- } else if (reg == CPSR_REGISTER - 1) {
- // Dummy FPA register, ignore
- } else if (reg < CPSR_REGISTER) {
- // Dummy FPA registers, ignore
- i += 2;
- } else if (reg > CPSR_REGISTER && reg < FPSCR_REGISTER) {
- Core::CPU().SetVFPReg(reg - CPSR_REGISTER - 1, GdbHexToInt(buffer_ptr + i * CHAR_BIT));
- i++; // Skip padding
- } else if (reg == FPSCR_REGISTER) {
+ Core::CPU().SetCPSR(GdbHexToInt(buffer_ptr + i * 16));
+ } else {
UNIMPLEMENTED();
}
}
@@ -642,13 +684,13 @@ static void ReadMemory() {
auto start_offset = command_buffer + 1;
auto addr_pos = std::find(start_offset, command_buffer + command_length, ',');
- VAddr addr = HexToInt(start_offset, static_cast<u32>(addr_pos - start_offset));
+ VAddr addr = HexToLong(start_offset, static_cast<u64>(addr_pos - start_offset));
start_offset = addr_pos + 1;
- u32 len =
- HexToInt(start_offset, static_cast<u32>((command_buffer + command_length) - start_offset));
+ u64 len =
+ HexToLong(start_offset, static_cast<u64>((command_buffer + command_length) - start_offset));
- LOG_DEBUG(Debug_GDBStub, "gdb: addr: %08x len: %08x\n", addr, len);
+ LOG_DEBUG(Debug_GDBStub, "gdb: addr: %016llx len: %016llx\n", addr, len);
if (len * 2 > sizeof(reply)) {
SendReply("E01");
@@ -670,11 +712,11 @@ static void ReadMemory() {
static void WriteMemory() {
auto start_offset = command_buffer + 1;
auto addr_pos = std::find(start_offset, command_buffer + command_length, ',');
- VAddr addr = HexToInt(start_offset, static_cast<u32>(addr_pos - start_offset));
+ VAddr addr = HexToLong(start_offset, static_cast<u64>(addr_pos - start_offset));
start_offset = addr_pos + 1;
auto len_pos = std::find(start_offset, command_buffer + command_length, ':');
- u32 len = HexToInt(start_offset, static_cast<u32>(len_pos - start_offset));
+ u64 len = HexToLong(start_offset, static_cast<u64>(len_pos - start_offset));
if (!Memory::IsValidVirtualAddress(addr)) {
return SendReply("E00");
@@ -727,8 +769,8 @@ static void Continue() {
* @param addr Address of breakpoint.
* @param len Length of breakpoint.
*/
-static bool CommitBreakpoint(BreakpointType type, PAddr addr, u32 len) {
- std::map<u32, Breakpoint>& p = GetBreakpointList(type);
+static bool CommitBreakpoint(BreakpointType type, PAddr addr, u64 len) {
+ std::map<u64, Breakpoint>& p = GetBreakpointList(type);
Breakpoint breakpoint;
breakpoint.active = true;
@@ -767,11 +809,11 @@ static void AddBreakpoint() {
auto start_offset = command_buffer + 3;
auto addr_pos = std::find(start_offset, command_buffer + command_length, ',');
- PAddr addr = HexToInt(start_offset, static_cast<u32>(addr_pos - start_offset));
+ PAddr addr = HexToLong(start_offset, static_cast<u64>(addr_pos - start_offset));
start_offset = addr_pos + 1;
- u32 len =
- HexToInt(start_offset, static_cast<u32>((command_buffer + command_length) - start_offset));
+ u64 len =
+ HexToLong(start_offset, static_cast<u64>((command_buffer + command_length) - start_offset));
if (type == BreakpointType::Access) {
// Access is made up of Read and Write types, so add both breakpoints
@@ -816,7 +858,7 @@ static void RemoveBreakpoint() {
auto start_offset = command_buffer + 3;
auto addr_pos = std::find(start_offset, command_buffer + command_length, ',');
- PAddr addr = HexToInt(start_offset, static_cast<u32>(addr_pos - start_offset));
+ PAddr addr = HexToLong(start_offset, static_cast<u64>(addr_pos - start_offset));
if (type == BreakpointType::Access) {
// Access is made up of Read and Write types, so add both breakpoints