diff options
Diffstat (limited to 'c/src/lib/libbsp/m68k/efi68k/startup/m68k-stub.c')
| -rw-r--r-- | c/src/lib/libbsp/m68k/efi68k/startup/m68k-stub.c | 782 |
1 files changed, 0 insertions, 782 deletions
diff --git a/c/src/lib/libbsp/m68k/efi68k/startup/m68k-stub.c b/c/src/lib/libbsp/m68k/efi68k/startup/m68k-stub.c deleted file mode 100644 index a37cd2dc83..0000000000 --- a/c/src/lib/libbsp/m68k/efi68k/startup/m68k-stub.c +++ /dev/null @@ -1,782 +0,0 @@ -/* m68k-stub.c - * - * $Id$ - */ - -#include <efi68k.h> -#include <rtems.h> - -m68k_isr_entry set_vector( - rtems_isr_entry handler, - rtems_vector_number vector, - int type -); - - -void (*exceptionHook)() = 0; - -void outbyte(char c); -char putDebugChar( char c) -{ - outbyte(c); - return c; -} - -char inbyte(void); -char getDebugChar(void) -{ - return inbyte(); -} - -void flush_i_cache(void) -{ - return; -} - -void *memset(void *p, int c, int n) -{ - register int i; - void *s=p; - - for (i=0;i<n;i++) *((char *)p)++=(char)c; - return s; -} - -char *db_strcpy(char *s, const char *t) -{ - char *save=s; - while((*s++ = *t++) != '\0'); - return save; -} - -int db_strlen(const char *s) -{ - int n; - - for (n=0; *s!='\0'; s++) n++; - return n; -} - -/************************************************************************ - * - * external low-level support routines - */ -typedef void (*ExceptionHook)(int); /* pointer to function with int parm */ -typedef void (*Function)(); /* pointer to a function */ - -/* extern Function exceptionHandler(); */ /* assign an exception handler */ -extern ExceptionHook exceptionHook; /* hook variable for errors/exceptions */ -/* extern void exceptionHandler(int vect, void (*function)()); */ - -/************************/ -/* FORWARD DECLARATIONS */ -/************************/ -static void initializeRemcomErrorFrame(); - -/************************************************************************/ -/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/ -/* at least NUMREGBYTES*2 are needed for register packets */ -#define BUFMAX 400 - -static char initialized; /* boolean flag. != 0 means we've been initialized */ - -int remote_debug; -/* debug > 0 prints ill-formed commands in valid packets & checksum errors */ - -static const char hexchars[]="0123456789abcdef"; - -/* there are 180 bytes of registers on a 68020 w/68881 */ -/* many of the fpa registers are 12 byte (96 bit) registers */ -#define NUMREGBYTES 180 -enum regnames {D0,D1,D2,D3,D4,D5,D6,D7, - A0,A1,A2,A3,A4,A5,A6,A7, - PS,PC, - FP0,FP1,FP2,FP3,FP4,FP5,FP6,FP7, - FPCONTROL,FPSTATUS,FPIADDR - }; - - - -typedef struct FrameStruct -{ - struct FrameStruct *previous; - int exceptionPC; /* pc value when this frame created */ - int exceptionVector; /* cpu vector causing exception */ - short frameSize; /* size of cpu frame in words */ - short sr; /* for 68000, this not always sr */ - int pc; - short format; - int fsaveHeader; - int morejunk[0]; /* exception frame, fp save... */ -} Frame; - -#define FRAMESIZE 10 -int gdbFrameStack[FRAMESIZE]; -static Frame *lastFrame; - -/* - * these should not be static cuz they can be used outside this module - */ -int registers[NUMREGBYTES/4]; -int superStack; - -#define STACKSIZE 600 -int remcomStack[STACKSIZE/sizeof(int)]; -static int* stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1]; - -static ExceptionHook oldExceptionHook; - -#define SAVE_FP_REGS() -#define RESTORE_FP_REGS() - -void return_to_super(); -void return_to_user(); - -asm(" -.text -.align 2 -.globl return_to_super -return_to_super: - oriw #0x0700,%sr - movel registers+60,%sp /* get new stack pointer */ - movel lastFrame,%a0 /* get last frame info */ - bra return_to_any - -.globl return_to_user -return_to_user: - oriw #0x0700,%sr - movel registers+60,%a0 /* get usp */ - movel %a0,%usp /* set usp */ - movel superStack,%sp /* get original stack pointer */ - -return_to_any: - movel lastFrame,%a0 /* get last frame info */ - movel %a0@+,lastFrame /* link in previous frame */ - addql #8,%a0 /* skip over pc, vector#*/ - movew %a0@+,%d0 /* get # of words in cpu frame */ - addw %d0,%a0 /* point to end of data */ - addw %d0,%a0 /* point to end of data */ - movel %a0,%a1 -# -# copy the stack frame - subql #1,%d0 -copyUserLoop: - movew %a1@-,%sp@- - dbf %d0,copyUserLoop -"); - RESTORE_FP_REGS() - asm(" moveml registers,%d0-%d7/%a0-%a6"); - asm(" rte"); /* pop and go! */ - -#define DISABLE_INTERRUPTS() asm(" oriw #0x0700,%sr"); -#define BREAKPOINT() asm(" trap #1"); - -/* this function is called immediately when a level 7 interrupt occurs */ -/* if the previous interrupt level was 7 then we're already servicing */ -/* this interrupt and an rte is in order to return to the debugger. */ -/* For the 68000, the offset for sr is 6 due to the jsr return address */ -asm(" -.text -.align 2 -.globl _debug_level7 -_debug_level7: - movew %d0,%sp@-"); -asm(" movew %sp@(6),%d0"); - -asm(" andiw #0x700,%d0 - cmpiw #0x700,%d0 - beq already7 - movew %sp@+,%d0 - bra _catchException -already7: - movew %sp@+,%d0"); -asm(" lea %sp@(4),%sp"); /* pull off 68000 return address */ - -asm(" rte"); - -extern void _catchException (); - -/* This function is called when an exception occurs. It translates the - * return address found on the stack into an exception vector # which - * is then handled by either handle_exception or a system handler. - * _catchException provides a front end for both. - * - * stack on entry: stack on exit: - * Program counter MSWord exception # MSWord - * Program counter LSWord exception # MSWord - * Status Register - * Return Address MSWord - * Return Address LSWord - */ - -asm(" -.text -.align 2 -.globl _catchException -_catchException: -"); -DISABLE_INTERRUPTS(); -asm(" - moveml %d0-%d7/%a0-%a6,registers /* save registers */ - movel lastFrame,%a0 /* last frame pointer */ - - move.b #64,(0x00600001) - move.b (0x00600007),%d0 - andib #-64,%d0 - move.b %d0,(0x00600007) - -"); -SAVE_FP_REGS(); -asm(" - lea registers,%a5 /* get address of registers */ - movel %sp@+,%d2 /* pop return address */ - addq.l #6,%d2 - sub.l #0x200000,%d2 - divs #6,%d2 -/* addl #1530,%d2 */ /* convert return addr to */ -/* divs #6,%d2 */ /* exception number */ - extl %d2 - - moveql #3,%d3 /* assume a three word frame */ - - cmpiw #3,%d2 /* bus error or address error ? */ - bgt normal /* if >3 then normal error */ - movel %sp@+,%a0@- /* copy error info to frame buff*/ - movel %sp@+,%a0@- /* these are never used */ - moveql #7,%d3 /* this is a 7 word frame */ - -normal: - movew %sp@+,%d1 /* pop status register */ - movel %sp@+,%a4 /* pop program counter */ - movew %d1,%a5@(66) /* save sr */ - movel %a4,%a5@(68) /* save pc in _regisers[] */ - movel %a4,%a0@- /* copy pc to frame buffer */ - movew %d1,%a0@- /* copy sr to frame buffer */ - - movel %sp,superStack /* save supervisor sp */ - - andiw #0x2000,%d1 /* were we in supervisor mode ? */ - beq userMode - movel %a7,%a5@(60) /* save a7 */ - bra saveDone -userMode: - movel %usp,%a1 /* save user stack pointer */ - movel %a1,%a5@(60) /* save user stack pointer */ -saveDone: - - movew %d3,%a0@- /* push frame size in words */ - movel %d2,%a0@- /* push vector number */ - movel %a4,%a0@- /* push exception pc */ - -# -# save old frame link and set the new value - movel lastFrame,%a1 /* last frame pointer */ - movel %a1,%a0@- /* save pointer to prev frame */ - movel %a0,lastFrame - - movel %d2,%sp@- /* push exception num */ - movel exceptionHook,%a0 /* get address of handler */ - jbsr %a0@ /* and call it */ - clrl %sp@ /* replace exception num parm with frame ptr*/ - jbsr _returnFromException /* jbsr, but never returns */ -"); - - -/* - * remcomHandler is a front end for handle_exception. It moves the - * stack pointer into an area reserved for debugger use in case the - * breakpoint happened in supervisor mode. - */ -asm("remcomHandler:"); -asm(" addl #4,%sp"); /* pop off return address */ -asm(" movel %sp@+,%d0"); /* get the exception number */ -asm(" movel stackPtr,%sp"); /* move to remcom stack area */ -asm(" movel %d0,%sp@-"); /* push exception onto stack */ -asm(" andiw #0xf8ff,%sr"); -asm(" jbsr handle_exception"); /* this never returns */ -asm(" rts"); /* return */ - -void _returnFromException( Frame *frame ) -{ - /* if no passed in frame, use the last one */ - if (! frame) - { - frame = lastFrame; - frame->frameSize = 4; - frame->format = 0; - frame->fsaveHeader = -1; /* restore regs, but we dont have fsave info*/ - } - - - /* a 68000 cannot use the internal info pushed onto a bus error - * or address error frame when doing an RTE so don't put this info - * onto the stack or the stack will creep every time this happens. - */ - frame->frameSize=3; - - - /* throw away any frames in the list after this frame */ - lastFrame = frame; - - frame->sr = registers[(int) PS]; - frame->pc = registers[(int) PC]; - - if (registers[(int) PS] & 0x2000) - { - /* return to supervisor mode... */ - return_to_super(); - } - else - { /* return to user mode */ - return_to_user(); - } -} - -int hex(ch) -char ch; -{ - if ((ch >= 'a') && (ch <= 'f')) return (ch-'a'+10); - if ((ch >= '0') && (ch <= '9')) return (ch-'0'); - if ((ch >= 'A') && (ch <= 'F')) return (ch-'A'+10); - return (-1); -} - - -/* scan for the sequence $<data>#<checksum> */ -void getpacket(buffer) -char * buffer; -{ - unsigned char checksum; - unsigned char xmitcsum; - int i; - int count; - char ch; - - do { - /* wait around for the start character, ignore all other characters */ - while ((ch = getDebugChar()) != '$'); - checksum = 0; - xmitcsum = -1; - - count = 0; - - /* now, read until a # or end of buffer is found */ - while (count < BUFMAX) { - ch = getDebugChar(); - if (ch == '#') break; - checksum = checksum + ch; - buffer[count] = ch; - count = count + 1; - } - buffer[count] = 0; - - if (ch == '#') { - xmitcsum = hex(getDebugChar()) << 4; - xmitcsum += hex(getDebugChar()); - - if (checksum != xmitcsum) putDebugChar('-'); /* failed checksum */ - else { - putDebugChar('+'); /* successful transfer */ - /* if a sequence char is present, reply the sequence ID */ - if (buffer[2] == ':') { - putDebugChar( buffer[0] ); - putDebugChar( buffer[1] ); - /* remove sequence chars from buffer */ - count = db_strlen(buffer); - for (i=3; i <= count; i++) buffer[i-3] = buffer[i]; - } - } - } - } while (checksum != xmitcsum); - -} - -/* send the packet in buffer. The host get's one chance to read it. - This routine does not wait for a positive acknowledge. */ - - -void putpacket(buffer) -char * buffer; -{ - unsigned char checksum; - int count; - char ch; - - /* $<packet info>#<checksum>. */ - do { - putDebugChar('$'); - checksum = 0; - count = 0; - - while ((ch=buffer[count])) { - if (! putDebugChar(ch)) return; - checksum += ch; - count += 1; - } - - putDebugChar('#'); - putDebugChar(hexchars[checksum >> 4]); - putDebugChar(hexchars[checksum % 16]); - - } while (1 == 0); /* (getDebugChar() != '+'); */ - -} - -char remcomInBuffer[BUFMAX]; -char remcomOutBuffer[BUFMAX]; -static short error; - - -void debug_error(format, parm) -char * format; -char * parm; -{ - return; -} - -/* convert the memory pointed to by mem into hex, placing result in buf */ -/* return a pointer to the last char put in buf (null) */ -char* mem2hex(mem, buf, count) -char* mem; -char* buf; -int count; -{ - int i; - unsigned char ch; - for (i=0;i<count;i++) { - ch = *mem++; - *buf++ = hexchars[ch >> 4]; - *buf++ = hexchars[ch % 16]; - } - *buf = 0; - return(buf); -} - -/* convert the hex array pointed to by buf into binary to be placed in mem */ -/* return a pointer to the character AFTER the last byte written */ -char* hex2mem(buf, mem, count) -char* buf; -char* mem; -int count; -{ - int i; - unsigned char ch; - for (i=0;i<count;i++) { - ch = hex(*buf++) << 4; - ch = ch + hex(*buf++); - *mem++ = ch; - } - return(mem); -} - -/* this function takes the 68000 exception number and attempts to - translate this number into a unix compatible signal value */ -int computeSignal( exceptionVector ) -int exceptionVector; -{ - int sigval; - switch (exceptionVector) { - case 2 : sigval = 10; break; /* bus error */ - case 3 : sigval = 10; break; /* address error */ - case 4 : sigval = 4; break; /* illegal instruction */ - case 5 : sigval = 8; break; /* zero divide */ - case 6 : sigval = 8; break; /* chk instruction */ - case 7 : sigval = 8; break; /* trapv instruction */ - case 8 : sigval = 11; break; /* privilege violation */ - case 9 : sigval = 5; break; /* trace trap */ - case 10: sigval = 4; break; /* line 1010 emulator */ - case 11: sigval = 4; break; /* line 1111 emulator */ - - /* Coprocessor protocol violation. Using a standard MMU or FPU - this cannot be triggered by software. Call it a SIGBUS. */ - case 13: sigval = 10; break; - - case 31: sigval = 2; break; /* interrupt */ - case 33: sigval = 5; break; /* breakpoint */ - - /* This is a trap #8 instruction. Apparently it is someone's software - convention for some sort of SIGFPE condition. Whose? How many - people are being screwed by having this code the way it is? - Is there a clean solution? */ - case 40: sigval = 8; break; /* floating point err */ - - case 48: sigval = 8; break; /* floating point err */ - case 49: sigval = 8; break; /* floating point err */ - case 50: sigval = 8; break; /* zero divide */ - case 51: sigval = 8; break; /* underflow */ - case 52: sigval = 8; break; /* operand error */ - case 53: sigval = 8; break; /* overflow */ - case 54: sigval = 8; break; /* NAN */ - default: - sigval = 7; /* "software generated"*/ - } - return (sigval); -} - -/**********************************************/ -/* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */ -/* RETURN NUMBER OF CHARS PROCESSED */ -/**********************************************/ -int hexToInt(char **ptr, int *intValue) -{ - int numChars = 0; - int hexValue; - - *intValue = 0; - - while (**ptr) - { - hexValue = hex(**ptr); - if (hexValue >=0) - { - *intValue = (*intValue <<4) | hexValue; - numChars ++; - } - else - break; - - (*ptr)++; - } - - return (numChars); -} - -/* - * This function does all command procesing for interfacing to gdb. - */ -void handle_exception(int exceptionVector) -{ - int sigval; - int addr, length; - char * ptr; - int newPC; - Frame *frame; - - /* reply to host that an exception has occurred */ - sigval = computeSignal( exceptionVector ); - remcomOutBuffer[0] = 'S'; - remcomOutBuffer[1] = hexchars[sigval >> 4]; - remcomOutBuffer[2] = hexchars[sigval % 16]; - remcomOutBuffer[3] = 0; - - putpacket(remcomOutBuffer); - - while (1==1) { - error = 0; - remcomOutBuffer[0] = 0; - getpacket(remcomInBuffer); - switch (remcomInBuffer[0]) { - case '?' : remcomOutBuffer[0] = 'S'; - remcomOutBuffer[1] = hexchars[sigval >> 4]; - remcomOutBuffer[2] = hexchars[sigval % 16]; - remcomOutBuffer[3] = 0; - break; - case 'd' : remote_debug = !(remote_debug); /* toggle debug flag */ - break; - case 'g' : /* return the value of the CPU registers */ - mem2hex((char*) registers, remcomOutBuffer, NUMREGBYTES); - break; - case 'G' : /* set the value of the CPU registers - return OK */ - hex2mem(&remcomInBuffer[1], (char*) registers, NUMREGBYTES); - db_strcpy(remcomOutBuffer,"OK"); - break; - - /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ - case 'm' : - /* TRY TO READ %x,%x. IF SUCCEED, SET PTR = 0 */ - ptr = &remcomInBuffer[1]; - if (hexToInt(&ptr,&addr)) - if (*(ptr++) == ',') - if (hexToInt(&ptr,&length)) - { - ptr = 0; - mem2hex((char*) addr, remcomOutBuffer, length); - } - - if (ptr) - { - db_strcpy(remcomOutBuffer,"E01"); - debug_error("malformed read memory command: %s",remcomInBuffer); - } - break; - - /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */ - case 'M' : - /* TRY TO READ '%x,%x:'. IF SUCCEED, SET PTR = 0 */ - ptr = &remcomInBuffer[1]; - if (hexToInt(&ptr,&addr)) - if (*(ptr++) == ',') - if (hexToInt(&ptr,&length)) - if (*(ptr++) == ':') - { - hex2mem(ptr, (char*) addr, length); - ptr = 0; - db_strcpy(remcomOutBuffer,"OK"); - } - if (ptr) - { - db_strcpy(remcomOutBuffer,"E02"); - debug_error("malformed write memory command: %s",remcomInBuffer); - } - break; - - /* cAA..AA Continue at address AA..AA(optional) */ - /* sAA..AA Step one instruction from AA..AA(optional) */ - case 'c' : - case 's' : - /* try to read optional parameter, pc unchanged if no parm */ - ptr = &remcomInBuffer[1]; - if (hexToInt(&ptr,&addr)) - registers[ PC ] = addr; - - newPC = registers[ PC]; - - /* clear the trace bit */ - registers[ PS ] &= 0x7fff; - - /* set the trace bit if we're stepping */ - if (remcomInBuffer[0] == 's') registers[ PS ] |= 0x8000; - - /* - * look for newPC in the linked list of exception frames. - * if it is found, use the old frame it. otherwise, - * fake up a dummy frame in returnFromException(). - */ - frame = lastFrame; - while (frame) - { - if (frame->exceptionPC == newPC) break; /* bingo! a match */ - /* - * for a breakpoint instruction, the saved pc may - * be off by two due to re-executing the instruction - * replaced by the trap instruction. Check for this. - */ - if ((frame->exceptionVector == 33) && - (frame->exceptionPC == (newPC+2))) break; - if (frame == frame->previous) - { - frame = 0; /* no match found */ - break; - } - frame = frame->previous; - } - - /* - * If we found a match for the PC AND we are not returning - * as a result of a breakpoint (33), - * trace exception (9), nmi (31), jmp to - * the old exception handler as if this code never ran. - */ - if (frame) - { - if ((frame->exceptionVector != 9) && - (frame->exceptionVector != 31) && - (frame->exceptionVector != 33)) - { - /* - * invoke the previous handler. - */ - if (oldExceptionHook) - (*oldExceptionHook) (frame->exceptionVector); - newPC = registers[ PC ]; /* pc may have changed */ - if (newPC != frame->exceptionPC) - { - /* re-use the last frame, we're skipping it (longjump?)*/ - frame = (Frame *) 0; - _returnFromException( frame ); /* this is a jump */ - } - } - } - - /* if we couldn't find a frame, create one */ - if (frame == 0) - { - frame = lastFrame -1 ; - - /* by using a bunch of print commands with breakpoints, - it's possible for the frame stack to creep down. If it creeps - too far, give up and reset it to the top. Normal use should - not see this happen. - */ - if ((unsigned int) (frame-2) < (unsigned int) &gdbFrameStack) - { - initializeRemcomErrorFrame(); - frame = lastFrame; - } - frame->previous = lastFrame; - lastFrame = frame; - frame = 0; /* null so _return... will properly initialize it */ - } - - _returnFromException( frame ); /* this is a jump */ - - break; - - /* kill the program */ - case 'k' : /* do nothing */ - break; - } /* switch */ - - /* reply to the request */ - putpacket(remcomOutBuffer); - } -} - - -void -initializeRemcomErrorFrame() -{ - lastFrame = ((Frame *) &gdbFrameStack[FRAMESIZE-1]) - 1; - lastFrame->previous = lastFrame; -} - -/* this function is used to set up exception handlers for tracing and - breakpoints */ -void set_debug_traps() -{ - extern void _debug_level7(); - extern void remcomHandler(); - int exception; - - initializeRemcomErrorFrame(); - stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1]; - - for (exception = 2; exception <= 23; exception++) - set_vector(_catchException,exception,0); - - /* level 7 interrupt */ - set_vector(_debug_level7,31,0); - - /* breakpoint exception (trap #1) */ - set_vector(_catchException,33,0); - - /* This is a trap #8 instruction. Apparently it is someone's software - convention for some sort of SIGFPE condition. Whose? How many - people are being screwed by having this code the way it is? - Is there a clean solution? */ - set_vector(_catchException,40,0); - - /* 48 to 54 are floating point coprocessor errors */ - for (exception = 48; exception <= 54; exception++) - set_vector(_catchException,exception,0); - - if (oldExceptionHook != remcomHandler) - { - oldExceptionHook = exceptionHook; - exceptionHook = remcomHandler; - } - - initialized = 1; - -} - -/* This function will generate a breakpoint exception. It is used at the - beginning of a program to sync up with a debugger and can be used - otherwise as a quick means to stop program execution and "break" into - the debugger. */ - -void breakpoint() -{ - if (initialized) BREAKPOINT(); -} - |