Add exception dump generation and processing facilities

Detail:
  This set of changes adds support for the following features:
  * A new code system variable, Debugger$DumpOptions, to control whether exception/crash dumps are collected from SeriousErrorV and where they should be output
  * Dump output can be in raw (binary) or annotated (text) form.
  * Annotated form provides detailed annotation of the stack(s), detecting certain constructs such as SWI invocations, IRQsema frames, CMHG veneers, APCS stack frame chains, and most forms of assembler function calls. The output isn't as easy to understand as a proper stack backtrace would be, but the low-level nature allows it to cope with corrupt or partially-overwritten stack frames, and avoids making invasive changes to components in order to make them backtrace-friendly
  * Stack annotation is able to make use of embedded ROM debug symbols (to be supported by romlinker 0.06) and Norcroft-style embedded function names in order to provide function-level location information for most ROM components and applications
  * System variables Debugger$RawFile and Debugger$AnnotatedFile to specify where to save raw and annotated exception dumps (preliminary, approach may change in future)
  * As well as supporting saving to file, the exception dumps can also be sent to the HAL via HAL_DebugTX, or if a program is driving SeriousErrorV directly it can use SeriousErrorV_CustomReport to have it fed to a custom callback function
  The code is structured in such a way that the core dump annotation code can potentially be built into a standalone application to allow offline processing of dumps (offline application not part of this checkin)
  File changes:
  c/exc, h/exc - Core code for producing the annotated exception dumps
  hdr/ExcDump - Header detailing the format of the binary dump
  s/ExceptionDump - Code variable and SeriousErrorV handling. Several support calls (used by c/exc) are also implemented here, in order to separate the dump processing from any interrogation of the originating machine
  Makefile - Updated for c/exc inclusion, and C header generation from hdr/ExcDump
  Resources/UK/Messages, Resources/Germany/Messages - New messages used by exception dump code
  c/support - Add a strcmp implementation, and extend vsprintf to be vsnprintf. Add support for string width format specifier.
  s/Debugger - Workspace definitions and init/shutdown hooks for exception dump code. Refactor *Where so that the locate logic is separate from the message output logic, to allow the locate logic to be used by the exception dump code.
Admin:
  Tested on Raspberry Pi
  German messages in need of translation


Version 1.92. Tagged as 'Debugger-1_92'

Makefile

@@ -31,7 +31,7 @@ HELPSRC       = HelpSrc
 TOKENSOURCE   = TokHelpSrc
 TOKHELPSRC    = ${TOKENSOURCE}
 ASMHDRS       = Debugger
-OBJS          = Debugger util dis2_vfp support
+OBJS          = Debugger util dis2_vfp support exc
 HDRS          =
 CMHGFILE      =
 
@@ -116,9 +116,15 @@ dis2_vfp.o: dis2_vfp.c
 dis2_vfp.oz: dis2_vfp.c
 	${CC} ${CFLAGS} ${C_MODULE} -o $@ dis2_vfp.c
 
+excdump.h: hdr.ExcDump
+	${HDR2H} hdr.ExcDump $@
+
+exc.c: excdump.h
+
 clean::
 	${RM} c.dis2_vfp
 	${RM} c.dis2_arm
+	${RM} h.excdump
 	${RM} ${TOKENSOURCE}
 
 # Stuff from AAsmModule that's missing from CModule

VersionASM

@@ -11,13 +11,13 @@
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
                         GBLS    Module_ComponentPath
-Module_MajorVersion     SETS    "1.91"
-Module_Version          SETA    191
+Module_MajorVersion     SETS    "1.92"
+Module_Version          SETA    192
 Module_MinorVersion     SETS    ""
-Module_Date             SETS    "03 Mar 2016"
-Module_ApplicationDate  SETS    "03-Mar-16"
+Module_Date             SETS    "05 Apr 2016"
+Module_ApplicationDate  SETS    "05-Apr-16"
 Module_ComponentName    SETS    "Debugger"
 Module_ComponentPath    SETS    "castle/RiscOS/Sources/Programmer/Debugger"
-Module_FullVersion      SETS    "1.91"
-Module_HelpVersion      SETS    "1.91 (03 Mar 2016)"
+Module_FullVersion      SETS    "1.92"
+Module_HelpVersion      SETS    "1.92 (05 Apr 2016)"
                         END

VersionNum

-/* (1.91)
+/* (1.92)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        1.91
+#define Module_MajorVersion_CMHG        1.92
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                03 Mar 2016
+#define Module_Date_CMHG                05 Apr 2016
 
-#define Module_MajorVersion             "1.91"
-#define Module_Version                  191
+#define Module_MajorVersion             "1.92"
+#define Module_Version                  192
 #define Module_MinorVersion             ""
-#define Module_Date                     "03 Mar 2016"
+#define Module_Date                     "05 Apr 2016"
 
-#define Module_ApplicationDate          "03-Mar-16"
+#define Module_ApplicationDate          "05-Apr-16"
 
 #define Module_ComponentName            "Debugger"
 #define Module_ComponentPath            "castle/RiscOS/Sources/Programmer/Debugger"
 
-#define Module_FullVersion              "1.91"
-#define Module_HelpVersion              "1.91 (03 Mar 2016)"
-#define Module_LibraryVersionInfo       "1:91"
+#define Module_FullVersion              "1.92"
+#define Module_HelpVersion              "1.92 (05 Apr 2016)"
+#define Module_LibraryVersionInfo       "1:92"

c/support

@@ -33,6 +33,18 @@ char *strcat(char *str1,const char *str2)
 	return ret;
 }
 
+int strcmp(const char *str1, const char *str2)
+{
+	char c;
+	int diff;
+	do
+	{
+		c = *str1++;
+		diff = c - *str2++;
+	} while (c && !diff);
+	return diff;
+}
+
 void *memcpy(void *ptr1,const void *ptr2,size_t n)
 {
 	while(n--)
@@ -46,7 +58,7 @@ int sprintf(char *out,const char *format,...)
 {
 	va_list a;
 	va_start(a,format);
-	int ret = vsprintf(out,format,a);
+	int ret = vsnprintf(out,SIZE_MAX,format,a);
 	va_end(a);
 	return ret;
 }
@@ -57,21 +69,49 @@ int _sprintf(char *out,const char *format,...)
 {
 	va_list a;
 	va_start(a,format);
-	int ret = vsprintf(out,format,a);
+	int ret = vsnprintf(out,SIZE_MAX,format,a);
+	va_end(a);
+	return ret;
+}
+
+int snprintf(char *out,size_t max,const char *format,...)
+{
+	va_list a;
+	va_start(a,format);
+	int ret = vsnprintf(out,max,format,a);
+	va_end(a);
+	return ret;
+}
+
+extern int _snprintf(char *out,size_t max,const char *format,...);
+
+int _snprintf(char *out,size_t max,const char *format,...)
+{
+	va_list a;
+	va_start(a,format);
+	int ret = vsnprintf(out,max,format,a);
 	va_end(a);
 	return ret;
 }
 
 int vsprintf(char *out,const char *format,va_list a)
 {
-	int count=0;
+	return vsnprintf(out,SIZE_MAX,format,a);
+}
+
+#define OUTC(C) do { char chr = C; if (count < usable_max) out[count] = chr; count++; } while(0)
+
+int vsnprintf(char *out,size_t max,const char *format,va_list a)
+{
+	size_t count=0;
 	int c;
+	size_t usable_max = (out ? max : 0);
 	while((c = *format++) != 0)
 	{
 		if(c == '%')
 		{
 			/* We'll only deal with the following format specifiers:
-			   %s   (control-terminated - to cope with messages)
+			   %[-<width>]s   (control-terminated - to cope with messages)
 			   %c
 			   %<width>[ll]X
 			   %<width>[ll]x
@@ -81,6 +121,8 @@ int vsprintf(char *out,const char *format,va_list a)
 			int width=0;
 			bool islong=false;
 			c = *format++;
+			if (c == '-')
+				c = *format++;
 			while((c >= '0') && (c <= '9'))
 			{
 				width = width*10 + c - '0';
@@ -91,12 +133,27 @@ int vsprintf(char *out,const char *format,va_list a)
 			case 's':
 				{
 				const char *s = va_arg(a,const char *);
-				while(*s >= ' ')
-					out[count++] = *s++;
+				if(width)
+				{
+					/* Assume left-justified */
+					do
+					{
+						OUTC(((*s >= ' ') ? *s++ : ' '));
+					}
+					while(--width);
+				}
+				else
+				{
+					while(*s >= ' ')
+					{
+						OUTC(*s++);
+						width--;
+					}
+				}
 				}
 				break;
 			case 'c':
-				out[count++] = va_arg(a,int);
+				OUTC(va_arg(a,int));
 				break;
 			case 'l':
 				islong = true;
@@ -116,16 +173,18 @@ int vsprintf(char *out,const char *format,va_list a)
 					width = 1;
 				do
 				{
-					unsigned int n = h>>60;
+					unsigned int n = (unsigned int) (h>>60);
 					if(n || (i<width))
 					{
 						width = 16;
+						char c2;
 						if(n <= 9)
-							out[count++] = n+'0';
+							c2 = n+'0';
 						else if(c == 'X')
-							out[count++] = n+'A'-10;
+							c2 = n+'A'-10;
 						else
-							out[count++] = n+'a'-10;
+							c2 = n+'a'-10;
+						OUTC(c2);
 					}
 					h=h<<4;
 				} while(--i >= 0);
@@ -138,7 +197,7 @@ int vsprintf(char *out,const char *format,va_list a)
 				if((i & 0x80000000) && (c == 'd'))
 				{
 					i = -i;
-					out[count++] = '-';
+					OUTC('-');
 				}
 				while(i)
 				{
@@ -151,7 +210,7 @@ int vsprintf(char *out,const char *format,va_list a)
 					}
 					while(width > k)
 					{
-						out[count++] = '0';
+						OUTC('0');
 						width--;
 					}
 					c = '0';
@@ -160,25 +219,24 @@ int vsprintf(char *out,const char *format,va_list a)
 						i -= j;
 						c++;
 					}
-					out[count++] = c;
+					OUTC(c);
 					width = k-1;
 				}
 				while(width-- >= 0)
-					out[count++] = '0';
+					OUTC('0');
 				}
 				break;
 			}
 		}
-		else if(c == '\\')
-		{
-			out[count++] = *format++;
-		}
 		else
 		{
-			out[count++] = c;
+			OUTC(c);
 		}
 	}
-	out[count] = 0;
+	if (out && max)
+	{
+		out[(count < max) ? count : (max-1)] = 0;
+	}
 	return count;
 }
 

h/exc

+/* Copyright 2016 Castle Technology Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef EXC_H
+#define EXC_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include "dis2.h"
+
+/* To avoid dynamic memory allocation we use a line buffer to collect annotations before they are output
+   The buffer acts as a sliding window, storing the annotations for a contiguous range of memory
+   The buffer is flushed in a lazy manner; we only emit entries once we need to add an annotation for an address which is outside the current window
+   This allows us to go back and add annotations up to LINEBUFFER_SIZE lines in the past (required for e.g. STM decoding) */
+#define LINEBUFFER_SIZE 32 /* 16 in an APCS frame plus 10 for a _kernel_swi_regs. But round up to power of 2 for simplicity. N.B. 32 is max due to use of bitflags */
+#define LINEBUFFER_COLUMNS 4 /* If we find some overlapping stack frames (e.g. from stale data on the stack) we output them in separate columns */
+#define LINEBUFFER_COLWIDTH 40
+
+typedef struct {
+	uint32_t val;
+	bool ok;
+} excresult;
+
+typedef enum {
+	/* Messages used in annotations */
+	EXC_MSG_NONE = 0,
+	EXC_MSG_SWI,
+	EXC_MSG_MAYBEPSR,
+	EXC_MSG_R14_DESC,
+	EXC_MSG_REGNO,
+	EXC_MSG_IRQSEMA,
+	EXC_MSG_PSR,
+	EXC_MSG_ASMCALL,
+	EXC_MSG_RETURN_2DESC,
+	EXC_MSG_APCS,
+	EXC_MSG_CMHG_R0,
+	EXC_MSG_CMHG_RN,
+	EXC_MSG_CMHG_R9,
+	EXC_MSG_RETURN_1DESC,
+	EXC_MSG_APCS_BROKEN,
+
+	/* Other messages */
+	EXC_MSG_UNKNOWN,
+	EXC_MSG_OUT_OF_ANNOT,
+	EXC_MSG_DUMP_CORRUPT,
+	EXC_MSG_BLOCK_MEM,
+	EXC_MSG_BLOCK_OSRSI6,
+	EXC_MSG_BLOCK_ERROR,
+	EXC_MSG_BLOCK_OSMEM16,
+	EXC_MSG_IRQ_STACK,
+	EXC_MSG_SVC_STACK,
+	EXC_MSG_USR_STACK,
+	EXC_MSG_END,
+	EXC_MSG_CALLTO,
+} exc_msg;
+
+/* This represents a single annotation block/column (e.g. decoded stack frame) */
+typedef struct exc_annotation_block {
+	uint8_t msgs[LINEBUFFER_SIZE]; /* Message type/number to display for the line */
+	uint32_t addrs[LINEBUFFER_SIZE][2]; /* Two addresses (or other values, e.g. SWI numbers) to display for the line */
+	uint32_t next_fp; /* Next FP value in an APCS stack frame chain - allows all frames within a chain to use the same column */
+	uint32_t min,max; /* Min/max address range of current (or last) block */
+	uint32_t lineflags; /* Each bit corresponds to a line in the buffer; bit is set if it's the middle of an annotation, clear if it's the start */
+} exc_annotation_block_t;
+
+typedef struct exc_context {
+	uint32_t lineaddr; /* The address of the first line in the buffer */
+	uint8_t line; /* The index of the first line in the buffer (it's a circular buffer) */
+	exc_annotation_block_t annotations[LINEBUFFER_COLUMNS];
+
+	const uint32_t *buffer; /* The buffer containing the dump blocks */
+	size_t bufferlen;
+#ifndef MODULE
+	const uint32_t *rom;
+	size_t romlen;
+#endif
+
+	void (*print)(void *param, const char *str);
+	void *print_param;
+} exc_context_t;
+
+typedef struct {
+	const uint32_t *symbols;
+	uint32_t romaddr;
+} romsymtable;
+
+extern __value_in_regs excresult ExcPeekMem2(exc_context_t *ctx, uint32_t addr);
+extern const char *ExcGetMsg(exc_context_t *ctx, exc_msg msg);
+extern void ExcDescribeAddr(exc_context_t *ctx, uint32_t addr, char *buf, size_t len);
+extern __value_in_regs romsymtable ExcGetROMSymbols(void);
+
+#endif

hdr/ExcDump

+; Copyright 2016 Castle Technology Ltd
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     http://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+;
+
+; Dump block format:
+; word 0: block length (including header)
+; word 1: block type
+;         0 -> memory dump
+;              word 2: base addr
+;              word 3+: data
+;         1 -> OSRSI6 item(s)
+;              word 2: base index
+;              word 3+: data
+;         2 -> register dump
+;              word 2+: data
+;         3 -> error block
+;              word 2+: data
+;         4 -> OS_Memory 16 items
+;              word 2: base item number
+;              word 3+: details of each item
+;                       base of area (R1)
+;                       address space allocated (R2)
+;                       actual memory used (R3)
+
+                       ^ 0
+ExcDump_Chunk_Memory   # 1
+ExcDump_Chunk_OSRSI6   # 1
+ExcDump_Chunk_Regs     # 1
+ExcDump_Chunk_Error    # 1
+ExcDump_Chunk_OSMem16  # 1
+
+                       ^ 0
+ExcDump_Reg_R0         # 1
+ExcDump_Reg_R1         # 1
+ExcDump_Reg_R2         # 1
+ExcDump_Reg_R3         # 1
+ExcDump_Reg_R4         # 1
+ExcDump_Reg_R5         # 1
+ExcDump_Reg_R6         # 1
+ExcDump_Reg_R7         # 1
+ExcDump_Reg_R8         # 1
+ExcDump_Reg_R9         # 1
+ExcDump_Reg_R10        # 1
+ExcDump_Reg_R11        # 1
+ExcDump_Reg_R12        # 1
+ExcDump_Reg_R13        # 1
+ExcDump_Reg_R14        # 1
+ExcDump_Reg_R15        # 1
+ExcDump_Reg_CPSR       # 1
+ExcDump_Reg_R13_usr    # 1
+ExcDump_Reg_R14_usr    # 1
+ExcDump_Reg_R13_svc    # 1
+ExcDump_Reg_R14_svc    # 1
+ExcDump_Reg_SPSR_svc   # 1
+ExcDump_Reg_R13_irq    # 1
+ExcDump_Reg_R14_irq    # 1
+ExcDump_Reg_SPSR_irq   # 1
+ExcDump_Reg_R13_abt    # 1
+ExcDump_Reg_R14_abt    # 1
+ExcDump_Reg_SPSR_abt   # 1
+ExcDump_Reg_R13_und    # 1
+ExcDump_Reg_R14_und    # 1
+ExcDump_Reg_SPSR_und   # 1
+ExcDump_Reg_Count      # 0
+
+ExcAnnotateAll_DescribeBlocks * 1
+
+        END

s/Debugger

@@ -247,8 +247,13 @@
         GET     Hdr:CPU.Arch
         GET     Hdr:OSRSI6
         GET     Hdr:VFPSupport
+        GET     Hdr:HighFSI
+        GET     Hdr:FileTypes
+        GET     Hdr:OSMisc
+        GET     Hdr:HALEntries
 
         GET     Hdr:Debugger
+        GET     hdr.ExcDump
 
         GET     VersionASM
 
@@ -382,6 +387,23 @@ DisReg_C        #       1               ; Prefix char for Co-pro registers
 CRelocOffset    #       4               ; Relocation offset used by C code
  ]
 
+DumpBuffer      #       4
+DumpBufferLen   #       4
+ExceptionBusy   #       4               ; Tracks state of exception dump code to avoid re-entry:
+                                        ; 0 -> idle
+                                        ; 1 -> stage 1 busy
+                                        ; 2 -> stage 2 busy
+ROMDebugSymbols #       4
+ROMBaseAddr     #       4
+DumpOptions     #       4
+DumpOption_HAL_Raw        * 1
+DumpOption_HAL_Annotated  * 2
+DumpOption_File_Raw       * 4
+DumpOption_File_Annotated * 8
+DumpOption_Collect        * 16          ; Collect but don't report
+DumpOptions_Default       * 0           ; Default options to use on module init
+DumpOptionsStr  #       44              ; Big enough for longest string
+
 StringBuffer    #       160             ; Temp string buffer. Big enough to
                                         ; hold a disassembled instruction
                                         ; and a full register set + three instrs
@@ -620,6 +642,8 @@ Debug_Init Entry
         MOV     r3, #17
         MOV     r14, #0
         STR     r14, MessageFile_Open
+        STR     r14, ROMDebugSymbols
+        STR     r14, ROMBaseAddr
 20      STR     r14, [r1], #4
         SUBS    r3, r3, #1
         BNE     %BT20
@@ -709,6 +733,31 @@ Debug_Init Entry
 ;
 
 40
+        ; Find ROM
+        MOV     r0, #ModHandReason_LookupName
+        ADRL    r1, Where_UMod
+        SWI     XOS_Module
+        BVS     %FT42
+        MOV     r4, r3, LSR #20
+        MOV     r4, r4, LSL #20
+        STR     r4, ROMBaseAddr
+
+        ; Find ROM debug symbols
+        MOV     r0, #15
+        MOV     r1, #0
+41
+        SWI     XOS_ReadSysInfo
+        MOVVS   r1, #0
+        CMP     r1, #0
+        BEQ     %FT42
+        CMP     r2, #ExtROMFooter_DebugSymbols
+        CMPEQ   r3, #4
+        BNE     %BT41
+        LDW     r0, r1, r2, r3
+        ADD     r0, r0, r4
+        STR     r0, ROMDebugSymbols
+42
+
         ; SAR
         MOV     R3, #0
         STR     R3, DisOpts
@@ -719,6 +768,13 @@ Debug_Init Entry
 	BLVC    declareresourcefsfiles
 	]
 
+        MOV     R3, #DumpOptions_Default
+        STR     R3, DumpOptions
+        BLVC    ExcDump_CodeVar_Init
+      [ DumpOptions_Default <> 0
+        BLVC    ExcDump_Init
+      ]
+
         EXIT
 
 ; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
@@ -776,6 +832,8 @@ Debug_Die Entry
 
         LDR     wp, [r12]
 
+        BL      ExcDump_CodeVar_Shutdown
+
         BL      SwapAllBreakpoints      ; Be nice
 
         MOV     r0, #ExceptionDumpArea  ; Restore old exception dump area
@@ -2273,6 +2331,7 @@ BxTAB   DCB     "BX", 0
 BxjTAB  DCB     "BXJ",0
         ALIGN
 
+AdrTAB  DCB     "ADR",0
 BkptTAB DCB     "BKPT",0
 
         ALIGN
@@ -2570,7 +2629,6 @@ Mul16   ROUT
         B       InstructionEnd
 
 
-AdrTAB  DCB     "ADR",0
 MrsTAB  DCB     "MRS",0
 MsrTAB  DCB     "MSR",0
 BlxTAB  DCB     "BLX",0
@@ -6370,7 +6428,6 @@ Where_Code Entry "r6-r11"
         LDREQB  r0, SysIs32bit
         TEQEQ   r0, #0
         BICEQ   r7, r7, #ARM_CC_Mask
-        MOV     r8, #0                  ; No details
 
         BL      message_writes
         DCB     "M15", 0                ; "Address &"
@@ -6381,6 +6438,50 @@ Where_Code Entry "r6-r11"
         SWIVC   XOS_WriteI+space
         EXIT    VS
 
+        BL      Where_Util
+        EXIT    VS
+
+        CMP     r7, #-1
+        BNE     %FT85
+        ; Say "is <somewhere vague>"
+        BL      message_write0
+        B       %FT88
+85
+        ; Say "is at offset &xx in <some area> 'detail'"
+        ; => r0 -> area name token
+        ;    r7 = offset
+        ;    r8 -> detail string
+        BL      message_writes
+        DCB     "M21", 0
+        ALIGN
+        MOVVC   r10, r7
+        BLVC    DisplayHexWord
+        SWIVC   OS_WriteI+space
+        BLVC    message_write0
+        TEQ     r8, #0                  ; NULL details? V preserved
+        BEQ     %FT88
+
+        SWIVC   OS_WriteI+space
+        SWIVC   OS_WriteI+"'"
+        MOVVC   r0, r8
+        SWIVC   OS_Write0
+        SWIVC   OS_WriteI+"'"
+88
+        SWIVC   OS_NewLine
+        EXIT
+
+
+; In:
+; r7 = address
+; Out:
+; r0 -> area name token
+; r7 = offset
+; r8 -> detail string
+; offset is -1 if unsure of location
+Where_Util      ROUT
+        Entry "r1-r6,r9-r11"
+        MOV     r8, #0                  ; No details
+
         ; Applications sometimes go pop
         MOV     r0, #-1
         SWI     XOS_ReadDynamicArea
@@ -6467,43 +6568,44 @@ Where_Code Entry "r6-r11"
         ADRCS   r0, Where_NotMapped     ; C set, is not RAM
         ADRCC   r0, Where_Unknown       ; Somewhere, but not sure where
 80
-        ; Say "is <somewhere vague>"
-        BL      message_write0
-        B       %FT88
+        MOV     r7, #-1
+        MOV     r8, #0
 85
-        ; Say "is at offset &xx in <some area> 'detail'"
-        ; => r0 -> area name token
-        ;    r7 = offset
-        ;    r8 -> detail string
-        BL      message_writes
-        DCB     "M21", 0
-        ALIGN
-        MOVVC   r10, r7
-        BLVC    DisplayHexWord
-        SWIVC   OS_WriteI+space
-        BLVC    message_write0
-        TEQ     r8, #0                  ; NULL details? V preserved
-        BEQ     %FT88
-
-        SWIVC   OS_WriteI+space
-        SWIVC   OS_WriteI+"'"
-        MOVVC   r0, r8
-        SWIVC   OS_Write0
-        SWIVC   OS_WriteI+"'"
-88
-        SWIVC   OS_NewLine
         EXIT
 
-Where_Unknown   DCB     "M28", 0
-Where_NotMapped DCB     "M30", 0
-Where_ROM       DCB     "M34", 0
-Where_Module    DCB     "M47", 0
-Where_AppSlot   DCB     "M88", 0
-Where_DynArea   DCB     "M89", 0
-Where_Kernel    DCB     "M95", 0
-Where_SysWksp   DCB     "M96", 0
+Where_Unknown   DCB     "M28", 0 ; vague
+Where_NotMapped DCB     "M30", 0 ; vague
+Where_ROM       DCB     "M34", 0 ; offset
+Where_Module    DCB     "M47", 0 ; offset+detail
+Where_AppSlot   DCB     "M88", 0 ; offset
+Where_DynArea   DCB     "M89", 0 ; offset+detail
+Where_Kernel    DCB     "M95", 0 ; offset
+Where_SysWksp   DCB     "M96", 0 ; vague
         ALIGN
 
+; In:
+; r0 = address
+; r1 -> result buffer (area name, offset, detail string)
+        EXPORT  Where_Util_FromC
+Where_Util_FromC ROUT
+        Entry   "r1,r7,r8,r10"
+        SUB     r12, sl, #:INDEX:CRelocOffset
+        MOV     r7, r0
+        BL      Where_Util
+        ADDVS   r0, r0, #4
+        MOVVS   r7, #-1
+        MOVVS   r8, #0
+        FRAMLDR r1
+        BVS     %FT50
+        MOVS    r10, r0
+        BEQ     %FT50
+        BL      lookup_r10
+        ADDVS   r10, r0, #4
+        MOV     r0, r10
+50
+        STMIA   r1, {r0,r7,r8}
+        EXIT
+
 ; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
 
@@ -6534,5 +6636,6 @@ declareresourcefsfiles
       ]
         GET     Thumb.s
         GET     CodeVar.s
+        GET     ExceptionDump.s
 
         END