From c2d116fa44be20bce8c3726516638d442b0aed9e Mon Sep 17 00:00:00 2001
From: maxgerhardt <maximilian.gerhardt@rub.de>
Date: Fri, 30 Jun 2023 14:44:06 +0200
Subject: [PATCH] Implement better monitor commands for GDB
---
minichlink/microgdbstub.h | 93 +++++++++++++++++++++++++++++++++++++--
minichlink/minichgdb.c | 6 +--
minichlink/minichlink.c | 2 +-
3 files changed, 93 insertions(+), 8 deletions(-)
diff --git a/minichlink/microgdbstub.h b/minichlink/microgdbstub.h
index ef39150..919122e 100644
--- a/minichlink/microgdbstub.h
+++ b/minichlink/microgdbstub.h
@@ -30,7 +30,7 @@ void RVDebugExec( void * dev, int halt_reset_or_resume );
int RVReadMem( void * dev, uint32_t memaddy, uint8_t * payload, int len );
int RVHandleBreakpoint( void * dev, int set, uint32_t address );
int RVWriteRAM(void * dev, uint32_t memaddy, uint32_t length, uint8_t * payload );
-void RVCommandResetPart( void * dev );
+void RVCommandResetPart( void * dev, int mode );
void RVHandleDisconnect( void * dev );
void RVHandleGDBBreakRequest( void * dev );
void RVHandleKillRequest( void * dev );
@@ -106,6 +106,24 @@ static int fromhex( char c )
return c;
}
+// output must have length of len / 2.
+static int DecodeHexToBytes(const char* hexstr, size_t string_len, void* output, size_t out_len) {
+ // 2 hex chars make up one byte. out buffer needs to have >= slen/2 bytes.
+ // further, we only want to decode even-length strings
+ if (out_len < (string_len / 2) || (string_len % 2) != 0)
+ return -1;
+ uint8_t* out = (uint8_t*) output;
+ for(size_t i = 0; i < string_len; i += 2) {
+ int nibble1, nibble2;
+ if((nibble1 = fromhex(hexstr[i])) < 0)
+ return nibble1; // error
+ if((nibble2 = fromhex(hexstr[i + 1])) < 0)
+ return nibble2; // error
+ out[i / 2] = ((uint8_t)nibble1 << 4u) | ((uint8_t)nibble2);
+ }
+ return string_len / 2; // number of output bytes written
+}
+
// if (numhex < 0)
static int ReadHex( char ** instr, int numhex, uint32_t * outwrite )
{
@@ -157,6 +175,19 @@ void SendReplyFull( const char * replyMessage )
MicroGDBStubSendReply( replyMessage, -1, '$' );
}
+void MakeGDBPrintText(const char* msg) {
+ // ASCII to hex conversion doubles size, plus 'O', plus NUL
+ size_t buf_len = 2 * strlen(msg) + 2;
+ char* buf = alloca(buf_len);
+ memset(buf, 0, buf_len);
+ buf[0] = 'O'; // for "Output"
+ char* target = buf + 1;
+ for(size_t i = 0; i < strlen(msg); i++) {
+ target[2*i] = ToHEXNibble((msg[i] & 0xf0u) >> 4u);
+ target[2*i + 1] = ToHEXNibble(msg[i] & 0x0fu);
+ }
+ SendReplyFull(buf);
+}
///////////////////////////////////////////////////////////////////////////////
// General Protocol
@@ -191,10 +222,64 @@ void HandleGDBPacket( void * dev, char * data, int len )
SendReplyFull( "" );
else if( StringMatch( data, "TStatus" ) ) // Trace-Status
SendReplyFull( "" );
- else if( StringMatch( data, "Rcmd,7265736574" ) ) // "monitor reset"
+ else if( StringMatch( data, "Rcmd," ) ) // "monitor <command>"
{
- RVCommandResetPart( dev ); // Force reset
- SendReplyFull( "+" );
+ // will e.g. be "Rcmd,7265736574#"
+ // hex-decode the rest of it back to ASCII
+ char* cmdHex = data + strlen("Rcmd,");
+ // check if cmd is empty (no character or only '#' following)
+ if(strlen(cmdHex) > 1) {
+ char cmd[128];
+ memset(cmd, 0, sizeof(cmd));
+ if ( DecodeHexToBytes(cmdHex, strlen(cmdHex) - 1, cmd, sizeof(cmd) - 1) < 0 ) {
+ // decoding failed
+ SendReplyFull( "" );
+ break;
+ }
+ printf("Got monitor command: %s\n", cmd);
+ // Support commands that OpenOCD also does:
+ // https://openocd.org/doc/html/General-Commands.html
+ if(StringMatch(cmd, "halt")) {
+ // only halt
+ RVCommandResetPart( dev, HALT_MODE_HALT_BUT_NO_RESET);
+ SendReplyFull( "+" );
+ }
+ else if(StringMatch(cmd, "reset halt")) {
+ // reset and keep halted after reset
+ RVCommandResetPart( dev, HALT_MODE_HALT_AND_RESET);
+ SendReplyFull( "+" );
+ }
+ else if(StringMatch(cmd, "reset run")) {
+ // reset and run (i.e., reboot)
+ RVCommandResetPart( dev, HALT_MODE_REBOOT);
+ SendReplyFull( "+" );
+ }
+ else if(StringMatch(cmd, "reset")) {
+ // same as reset run per OpenOCD
+ RVCommandResetPart( dev, HALT_MODE_REBOOT);
+ SendReplyFull( "+" );
+ } else if(StringMatch(cmd, "resume")) {
+ // just resume
+ RVCommandResetPart( dev, HALT_MODE_RESUME);
+ SendReplyFull( "+" );
+ } else if(StringMatch(cmd, "help")) {
+ static const char helptext[] =
+ "minichlink GDB monitor help:\n"
+ "- halt: Halt execution\n"
+ "- resume: Resume execution\n"
+ "- reset [halt, run]: Reset and optionally halt or run\n";
+ MakeGDBPrintText(helptext);
+ SendReplyFull( "+" );
+ }
+ else {
+ printf("Unknown monitor command '%s', use 'monitor help'.\n", cmd);
+ MakeGDBPrintText("Unknown monitor command, use 'monitor help'\n");
+ SendReplyFull( "-" );
+ }
+ } else {
+ MakeGDBPrintText("No monitor command given, use 'monitor help'\n");
+ SendReplyFull( "-" );
+ }
}
else if( StringMatch( data, "Xfer:memory-map" ) )
{
diff --git a/minichlink/minichgdb.c b/minichlink/minichgdb.c
index 2d839fd..774a2f1 100644
--- a/minichlink/minichgdb.c
+++ b/minichlink/minichgdb.c
@@ -71,9 +71,9 @@ void RVCommandEpilogue( void * dev )
MCF.WriteReg32( dev, DMDATA0, 0 );
}
-void RVCommandResetPart( void * dev )
+void RVCommandResetPart( void * dev , int mode)
{
- MCF.HaltMode( dev, HALT_MODE_HALT_AND_RESET );
+ MCF.HaltMode( dev, mode );
RVCommandPrologue( dev );
}
@@ -236,7 +236,7 @@ void RVDebugExec( void * dev, int halt_reset_or_resume )
}
}
- halt_reset_or_resume = 2;
+ halt_reset_or_resume = HALT_MODE_RESUME;
}
if( shadow_running_state != ( halt_reset_or_resume >= 2 ) )
diff --git a/minichlink/minichlink.c b/minichlink/minichlink.c
index 3314474..14e60e5 100644
--- a/minichlink/minichlink.c
+++ b/minichlink/minichlink.c
@@ -1705,7 +1705,7 @@ static int DefaultHaltMode( void * dev, int mode )
MCF.WriteReg32( dev, DMCFGR, 0x5aa50000 | (1<<10) ); // CFGR (1<<10 == Allow output from slave)
MCF.WriteReg32( dev, DMCFGR, 0x5aa50000 | (1<<10) ); // Bug in silicon? If coming out of cold boot, and we don't do our little "song and dance" this has to be called.
MCF.WriteReg32( dev, DMCONTROL, 0x80000001 ); // Make the debug module work properly.
- if( mode == 0 ) MCF.WriteReg32( dev, DMCONTROL, 0x80000003 ); // Reboot.
+ if( mode == HALT_MODE_HALT_AND_RESET ) MCF.WriteReg32( dev, DMCONTROL, 0x80000003 ); // Reboot.
MCF.WriteReg32( dev, DMCONTROL, 0x80000001 ); // Re-initiate a halt request.
// MCF.WriteReg32( dev, DMCONTROL, 0x00000001 ); // Clear Halt Request. This is recommended, but not doing it seems more stable.
// Sometimes, even if the processor is halted but the MSB is clear, it will spuriously start?
--
GitLab