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checkpoint
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@aappleby
aappleby committed Mar 30, 2023
1 parent 6247b43 commit 459a1fd
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Showing 9 changed files with 597 additions and 334 deletions.
1 change: 1 addition & 0 deletions .gdbinit
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@@ -1 +1,2 @@
#set debug remote 1
target extended-remote /dev/ttyACM1
1 change: 1 addition & 0 deletions .gitignore
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@@ -1 +1,2 @@
build
.vscode
295 changes: 210 additions & 85 deletions GDBServer.cpp
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Expand Up @@ -6,7 +6,7 @@
const char* memory_map = R"(<?xml version="1.0"?>
<!DOCTYPE memory-map PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN" "http://sourceware.org/gdb/gdb-memory-map.dtd">
<memory-map>
<memory type="flash" start="0x00000000" length="0x4000">
<memory type="flash" start="0x08000000" length="0x4000">
<property name="blocksize">64</property>
</memory>
<memory type="ram" start="0x20000000" length="0x800"/>
Expand Down Expand Up @@ -58,11 +58,6 @@ void GDBServer::put_byte(char b) {
//send_checksum += b;
cb_put(b);

if (!sending) {
log("\n<< ");
sending = true;
}

if (isprint(b)) {
log("%c", b);
}
Expand All @@ -75,11 +70,6 @@ char GDBServer::get_byte() {
auto b = cb_get();
//recv_checksum += b;

if (sending) {
log("\n>> ");
sending = false;
}

if (isprint(b)) {
log("%c", b);
}
Expand Down Expand Up @@ -237,7 +227,7 @@ void GDBServer::handle_M() {
}

for (int i = 0; i < len/4; i++) {
sl->put_mem(addr, recv.take_i32());
sl->set_mem(addr, recv.take_i32());
addr += 4;
}

Expand Down Expand Up @@ -273,7 +263,7 @@ void GDBServer::handle_P() {
unsigned int val = recv.take_u32();

if (!recv.error) {
sl->put_gpr(gpr, val);
sl->set_gpr(gpr, val);
send.set_packet("OK");
}
}
Expand Down Expand Up @@ -361,12 +351,13 @@ void GDBServer::handle_v() {
recv.take(':');
int addr = recv.take_i32();
recv.take(":");
log("\n");
log("recv.size %d\n", recv.size);
log("recv.cursor %d\n", recv.cursor);
int size = recv.size - recv.cursor;
log("Write size %d, write addr %x\n", size, addr);
recv.cursor = recv.size;
while(recv.cursor < recv.size) {
put_flash_cache(addr++, recv.take_char());
}
send.set_packet("OK");
}
else if (recv.match("Done")) {
flush_flash_cache();
send.set_packet("OK");
}
else if (recv.match("Erase")) {
Expand All @@ -376,14 +367,12 @@ void GDBServer::handle_v() {
int size = recv.take_i32();

if (recv.error) {
log("\nBad vFlashErase packet!\n");
send.set_packet("E00");
return;
}
else {
send.set_packet("OK");
}
}
else if (recv.match("Done")) {
send.set_packet("OK");
flash_erase(addr, size);

}
}
else if (recv.match("vKill")) {
Expand All @@ -396,87 +385,223 @@ void GDBServer::handle_v() {

//------------------------------------------------------------------------------

void GDBServer::loop() {
log("GDBServer::loop()\n");
void GDBServer::flash_erase(int addr, int size) {
// Erases must be page-aligned
if ((addr & 0x3F) || (size & 0x3F)) {
log("\n");
log("Bad vFlashErase - addr %x size %x\n", addr, size);
send.set_packet("E00");
return;
}

while(1) {
if (addr == 0x08000000 && size == 0x4000) {
log("erase chip 0x%08x\n", addr);
sl->wipe_chip();
send.set_packet("OK");
addr = 0x4000;
size = 0;
}
else if (((addr & 0x3FF) == 0) && (size >= 1024)) {
log("erase sector 0x%08x\n", addr);
sl->wipe_sector(addr);
addr += 1024;
size -= 1024;
}
else {
log("erase page 0x%08x\n", addr);
sl->wipe_page(addr);
addr += 64;
size -= 64;
}
if (size == 0) break;
}

// Wait for start char
while (get_byte() != '$');
send.set_packet("OK");
}

// Add bytes to packet until we see the end char
// Checksum is for the _escaped_ data.
recv.clear();
uint8_t checksum = 0;
while (1) {
char c = get_byte();
if (c == '#') {
break;
}
else if (c == '}') {
checksum += c;
c = get_byte();
checksum += c;
recv.put_buf(c ^ 0x20);
}
else {
checksum += c;
recv.put_buf(c);
//------------------------------------------------------------------------------

void GDBServer::put_flash_cache(int addr, uint8_t data) {
int page_offset = addr & 0x3F;
int page_base = addr & ~0x3F;

if (page_base != this->page_base) {
flush_flash_cache();
this->page_base = page_base;
}

if (this->page_bitmap & (1 << page_offset)) {
log("\nByte in flash page written multiple times\n");
}
else {
this->page_cache[page_offset] = data;
this->page_bitmap |= (1ull << page_offset);
}
}

//------------------------------------------------------------------------------

void GDBServer::flush_flash_cache() {
if (page_bitmap == 0) {
// empty page cache, nothing to do
//log("empty page write at 0x%08x\n", this->page_base);
}
else if (page_bitmap == 0xFFFFFFFFFFFFFFFF) {
// full page write
log("full page write at 0x%08x\n", this->page_base);

uint32_t* cursor = (uint32_t*)page_cache;
for (int y = 0; y < 4; y++) {
for (int x = 0; x < 4; x++) {
log("0x%08x ", cursor[x + y * 4]);
}
log("\n");
}
char expected_checksum = 0;
expected_checksum = (expected_checksum << 4) | from_hex(get_byte());
expected_checksum = (expected_checksum << 4) | from_hex(get_byte());
sl->write_flash(page_base, (uint32_t*)page_cache, 16);
}
else {
// partial page write
log("partial page write at 0x%08x, mask 0x%016llx\n", this->page_base, this->page_bitmap);

if (checksum != expected_checksum) {
log("\n");
log("Packet transmission error\n");
log("expected checksum 0x%02x\n", expected_checksum);
log("actual checksum 0x%02x\n", checksum);
put_byte('-');
continue;
// Merge the page cache with the current page in flash
uint32_t current_page[16];
for (int i = 0; i < 16; i++) {
current_page[i] = sl->get_mem(page_base + 4*i);
}

// Packet checksum OK, handle it.
put_byte('+');


handler_func h = nullptr;
for (int i = 0; i < handler_count; i++) {
if (cmp(handler_tab[i].name, recv.buf) == 0) {
h = handler_tab[i].handler;
uint8_t* cursor = (uint8_t*)current_page;
for (int i = 0; i < 64; i++) {
if ((page_bitmap & (1ull << i)) == 0) {
page_cache[i] = cursor[i];
}
}

if (h) {
recv.cursor = 0;
send.clear();
(*this.*h)();

if (recv.error) {
log("\nParse failure for packet!\n");
send.set_packet("E00");
}
else if (recv.cursor != recv.size) {
log("\nLeftover text in packet - \"%s\"\n", &recv.buf[recv.cursor]);
uint32_t* cursor2 = (uint32_t*)page_cache;
for (int y = 0; y < 4; y++) {
for (int x = 0; x < 4; x++) {
log("0x%08x ", cursor2[x + y * 4]);
}
log("\n");
}
else {
log("No handler for command %s\n", recv.buf);
send.set_packet("");

sl->write_flash(page_base, (uint32_t*)page_cache, 16);
}

this->page_bitmap = 0;
this->page_base = -1;
for (int i = 0; i < 64; i++) this->page_cache[i] = 0;
}

//------------------------------------------------------------------------------

void GDBServer::handle_packet() {
if (checksum != expected_checksum) {
log("\n");
log("Packet transmission error\n");
log("expected checksum 0x%02x\n", expected_checksum);
log("actual checksum 0x%02x\n", checksum);
put_byte('-');
return;
}

// Packet checksum OK, handle it.
put_byte('+');


handler_func h = nullptr;
for (int i = 0; i < handler_count; i++) {
if (cmp(handler_tab[i].name, recv.buf) == 0) {
h = handler_tab[i].handler;
}
}

if (h) {
recv.cursor = 0;
send.clear();
(*this.*h)();

if (!send.packet_valid) {
log("Handler created a bad packet '%s'\n", send.buf);
send.set_packet("");
if (recv.error) {
log("\nParse failure for packet!\n");
send.set_packet("E00");
}
else if (recv.cursor != recv.size) {
log("\nLeftover text in packet - \"%s\"\n", &recv.buf[recv.cursor]);
}
}
else {
log("No handler for command %s\n", recv.buf);
send.set_packet("");
}

if (!send.packet_valid) {
log("Handler created a bad packet '%s'\n", send.buf);
send.set_packet("");
}
}

//------------------------------------------------------------------------------

for (int retry = 0; retry < 5; retry++) {
if (send_packet()) break;
if (retry == 4) {
log("\nFailed to send packet after 5 retries\n");
void GDBServer::update(bool connected, char c) {
switch(state) {
case S_DISCONNECTED:
break;

case S_PREFIX:
// Wait for start char
if (c == '$') {
state = S_PACKET;
recv.clear();
checksum = 0;
}
}
break;

case S_PACKET:
// Add bytes to packet until we see the end char
// Checksum is for the _escaped_ data.
if (c == '#') {
expected_checksum = 0;
state = S_SUFFIX1;
}
else if (c == '}') {
checksum += c;
state = S_PACKET_ESCAPE;
}
else {
checksum += c;
recv.put_buf(c);
}
break;

case S_PACKET_ESCAPE:
checksum += c;
recv.put_buf(c ^ 0x20);
break;

case S_SUFFIX1:
expected_checksum = (expected_checksum << 4) | from_hex(c);
state = S_SUFFIX2;
break;

case S_SUFFIX2:
expected_checksum = (expected_checksum << 4) | from_hex(c);
handle_packet();
sending = true;
state = S_REPLY;
break;

case S_REPLY:
for (int retry = 0; retry < 5; retry++) {
if (send_packet()) break;
if (retry == 4) {
log("\nFailed to send packet after 5 retries\n");
}
}
sending = false;
state = S_PREFIX;
break;
}
}

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