m-labs · Aug 17, 2016 · Aug 17, 2016
Showing with 153 additions and 7 deletions.

+2 −0 misoc/software/libbase/crt0-or1k.S

+150 −6 misoc/software/libbase/exception.c

+1 −1 misoc/software/libcompiler-rt/Makefile
diff --git a/misoc/software/libbase/crt0-or1k.S b/misoc/software/libbase/crt0-or1k.S
@@ -202,6 +202,8 @@ _exception_handler:
     l.mfspr r5, r0, SPR_EPCR_BASE
     /* Extract exception effective address */
     l.mfspr r6, r0, SPR_EEAR_BASE
+    /* Extract exception SR */
+    l.mfspr r7, r0, SPR_ESR_BASE
     /* Call exception handler with the link address as argument */
     l.jal   exception_handler
      l.nop

diff --git a/misoc/software/libbase/exception.c b/misoc/software/libbase/exception.c
@@ -6,11 +6,13 @@ void isr(void);
 
 #ifdef __or1k__
 
+#include <hw/flags.h>
+
 #define EXTERNAL_IRQ 0x8
 
 static void emerg_printf(const char *fmt, ...)
 {
-	char buf[128];
+	char buf[512];
 	va_list args;
 	va_start(args, fmt);
 	vsnprintf(buf, sizeof(buf), fmt, args);
@@ -23,17 +25,158 @@ static void emerg_printf(const char *fmt, ...)
 	}
 }
 
+static char emerg_getc()
+{
+	while(uart_rxempty_read());
+	char c = uart_rxtx_read();
+	uart_ev_pending_write(UART_EV_RX);
+	return c;
+}
+
+static const char hex[] = "0123456789abcdef";
+
+static void gdb_send(const char *txbuf)
+{
+	unsigned char cksum = 0;
+	const char *p = txbuf;
+	while(*p) cksum += *p++;
+	emerg_printf("+$%s#%c%c", txbuf, hex[cksum >> 4], hex[cksum & 0xf]);
+}
+
+static void gdb_recv(char *rxbuf, size_t size)
+{
+	size_t pos = (size_t)-1;
+	for(;;) {
+		char c = emerg_getc();
+		if(c == '$')
+			pos = 0;
+		else if(c == '#')
+			return;
+		else if(pos < size - 1) {
+			rxbuf[pos++] = c;
+			rxbuf[pos] = 0;
+		}
+	}
+}
+
+static void gdb_stub(unsigned long pc, unsigned long sr,
+                     unsigned long r1, unsigned long *regs)
+{
+	gdb_send("S05");
+
+	char buf[385];
+	for(;;) {
+		gdb_recv(buf, sizeof(buf));
+
+		switch(buf[0]) {
+			case '?': {
+				snprintf(buf, sizeof(buf), "S05");
+				break;
+			}
+
+			case 'g': {
+				snprintf(buf, sizeof(buf),
+				         "%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x"
+				         "%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x"
+				         "%08x%08x%08x",
+				         0,        r1,       regs[2],  regs[3],  regs[4],  regs[5],  regs[6],  regs[7],
+				         regs[8],  regs[9],  regs[10], regs[11], regs[12], regs[13], regs[14], regs[15],
+				         regs[16], regs[17], regs[18], regs[19], regs[20], regs[21], regs[22], regs[23],
+				         regs[24], regs[25], regs[26], regs[27], regs[28], regs[29], regs[30], regs[31],
+				         pc-4,     pc,       sr);
+				break;
+			}
+
+			case 'm': {
+				unsigned long addr, len;
+				char *endptr = &buf[0];
+				addr  = strtoul(endptr + 1, &endptr, 16);
+				len   = strtoul(endptr + 1, &endptr, 16);
+				unsigned char *ptr = (unsigned char *)addr;
+				if(len > sizeof(buf) / 2) len = sizeof(buf) / 2;
+				for(size_t i = 0; i < len; i++) {
+					buf[i*2  ] = hex[ptr[i] >> 4];
+					buf[i*2+1] = hex[ptr[i] & 15];
+					buf[i*2+2] = 0;
+				}
+				break;
+			}
+
+			case 'p': {
+				unsigned long reg, value;
+				char *endptr = &buf[0];
+				reg   = strtoul(endptr + 1, &endptr, 16);
+				if(reg == 0)
+					value = 0;
+				else if(reg == 1)
+					value = r1;
+				else if(reg >= 2 && reg <= 31)
+					value = regs[reg];
+				else if(reg == 33)
+					value = pc;
+				else if(reg == 34)
+					value = sr;
+				else {
+					snprintf(buf, sizeof(buf), "E01");
+					break;
+				}
+				snprintf(buf, sizeof(buf), "%08x", value);
+				break;
+			}
+
+			case 'P': {
+				unsigned long reg, value;
+				char *endptr = &buf[0];
+				reg   = strtoul(endptr + 1, &endptr, 16);
+				value = strtoul(endptr + 1, &endptr, 16);
+				if(reg == 0)
+					/* ignore */;
+				else if(reg == 1)
+					r1 = value;
+				else if(reg >= 2 && reg <= 31)
+					regs[reg] = value;
+				else if(reg == 33)
+					pc = value;
+				else if(reg == 34)
+					sr = value;
+				else {
+					snprintf(buf, sizeof(buf), "E01");
+					break;
+				}
+				snprintf(buf, sizeof(buf), "OK");
+				break;
+			}
+
+			case 'c': {
+				if(buf[1] != '\0') {
+					snprintf(buf, sizeof(buf), "E01");
+					break;
+				}
+				return;
+			}
+
+			default:
+				snprintf(buf, sizeof(buf), "");
+				break;
+		}
+
+		do {
+			gdb_send(buf);
+		} while(emerg_getc() == '-');
+	}
+}
+
 void exception_handler(unsigned long vect, unsigned long *regs,
-                       unsigned long pc, unsigned long ea);
+                       unsigned long pc, unsigned long ea, unsigned long sr);
 void exception_handler(unsigned long vect, unsigned long *regs,
-                       unsigned long pc, unsigned long ea)
+                       unsigned long pc, unsigned long ea, unsigned long sr)
 {
 	if(vect == EXTERNAL_IRQ) {
 		isr();
 	} else {
 		emerg_printf("\n *** Unhandled exception %d *** \n", vect);
-		emerg_printf("   pc  %08x ea  %08x\n",
-		             pc, ea);
+		emerg_printf("   pc  %08x sr  %08x ea  %08x\n",
+		             pc, sr, ea);
 		unsigned long r1 = (unsigned long)regs + 4*32;
 		regs -= 2;
 		emerg_printf("   r0  %08x r1  %08x r2  %08x r3  %08x\n",
@@ -61,7 +204,8 @@ void exception_handler(unsigned long vect, unsigned long *regs,
 			}
 			emerg_printf("\n");
 		}
-		for(;;);
+		emerg_printf(" waiting for gdb... ");
+		gdb_stub(pc, sr, r1, regs);
 	}
 }
 #endif
diff --git a/misoc/software/libcompiler-rt/Makefile b/misoc/software/libcompiler-rt/Makefile
@@ -6,7 +6,7 @@ CFLAGS+=-D_YUGA_LITTLE_ENDIAN=0 -D_YUGA_BIG_ENDIAN=1 -Wno-missing-prototypes
 OBJECTS=divsi3.o modsi3.o comparesf2.o comparedf2.o negsf2.o negdf2.o addsf3.o subsf3.o mulsf3.o divsf3.o lshrdi3.o muldi3.o divdi3.o ashldi3.o ashrdi3.o udivmoddi4.o \
   floatsisf.o floatunsisf.o fixsfsi.o fixdfdi.o fixunssfsi.o fixunsdfdi.o adddf3.o subdf3.o muldf3.o divdf3.o floatsidf.o floatunsidf.o floatdidf.o fixdfsi.o fixunsdfsi.o \
   clzsi2.o ctzsi2.o udivdi3.o umoddi3.o moddi3.o ucmpdi2.o \
-  powidf2.o
+  powidf2.o powisf2.o mulodi4.o floatundisf.o floatundidf.o extendsfdf2.o truncdfsf2.o
 
 all: libcompiler-rt.a