diff options
Diffstat (limited to '')
| -rw-r--r-- | c/src/librdbg/src/m68k/rdbg_cpu_asm.S | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/c/src/librdbg/src/m68k/rdbg_cpu_asm.S b/c/src/librdbg/src/m68k/rdbg_cpu_asm.S new file mode 100644 index 0000000000..bd2d982943 --- /dev/null +++ b/c/src/librdbg/src/m68k/rdbg_cpu_asm.S @@ -0,0 +1,199 @@ +/* rdbg_cpu_asm.s + * + * This file contains all assembly code for the Motorola m68k implementation + * of RDBG. + * + * $Id$ + * + */ + +#include <asm.h> +#include <rtems/score/cpu.h> + + BEGIN_CODE + +/* + * void copyback_data_cache_and_invalidate_instr_cache(addr, size) + * + * This routine performs a copy of the data cache + * and invalidate the instruction cache + */ + + .align 2 + PUBLIC (copyback_data_cache_and_invalidate_instr_cache) + +SYM (copyback_data_cache_and_invalidate_instr_cache): + nop | how? + rts + + + +/* + * void enterRdbg(void) + * + * This function performs trap #4 + * It is used : + * 1 - in the user code, to simulate a Breakpoint. + * (with justSaveContext = 0) + * 2 - in the RDBG code, to push a ctx in the list. + * (with justSaveContext = 1) + * + * In most of case, it will be use as described in 1. + * The 2nd possibility will be used by RDBG to obtain + * its own ctx + */ + + PUBLIC (enterRdbg) + +SYM (enterRdbg): + trap #4 + rts + + +/* + * void excHandler(void) + * + * lotsa copypaste from cpu_asm.S + * + */ + +/* + * The RTEMS jump table pushes vector + * + * The two types of exception frames on m68000 are + * + * unsigned16 sr <- sp + * unsigned32 pc + * + * unsigned16 fc <- sp + * unsigned32 addr + * unsigned16 instr + * unsigned16 sr + * unsigned32 pc + * + * after real frame we push d0-d1/a0-a1 + * + * after that we push CPU_Exception_frame + * + * exframe <- sp + * d0-d1/a0-a1 + * frame + */ +#if ( M68K_COLDFIRE_ARCH == 1 ) +.set SR_OFFSET, 2 | Status register offset +.set PC_OFFSET, 4 | Program Counter offset +.set FVO_OFFSET, 0 | Format/vector offset +#elif ( M68K_HAS_VBR == 1 ) +.set SR_OFFSET, 0 | Status register offset +.set PC_OFFSET, 2 | Program Counter offset +.set FVO_OFFSET, 6 | Format/vector offset +#else +.set SR_OFFSET, 2 | Status register offset +.set PC_OFFSET, 4 | Program Counter offset +.set FVO_OFFSET, 0 | Format/vector offset placed in the stack +#endif /* M68K_HAS_VBR */ + + .align 4 + + PUBLIC (excHandler) + PUBLIC (BreakPointExcHdl) + +SYM (excHandler): +#if ( M68K_COLDFIRE_ARCH == 0 ) + moveml d0-d1/a0-a1,a7@- | save d0-d1,a0-a1 + movew a7@(16+FVO_OFFSET),d0 | d0 = F/VO + andl #0x0fff,d0 | d0 = vector offset in vbr +#else + lea a7@(-16),a7 + movm.l d0-d1/a0-a1,a7@ | save d0-d1,a0-a1 + movew a7@(16+FVO_OFFSET),d0 | d0 = F/VO + andl #0x0ffc,d0 | d0 = vector offset in vbr +#endif + lsrl #2,d0 | d0 = vector number + lea a7@(16),a1 | address of orig frame + lea a7@(16),a0 | address of orig frame +#if ( M68K_HAS_VBR == 0 ) + lea a0@(2),a0 | skip vector +#endif + lea a0@(6),a0 | a0 = orig sp + cmpiw #3,d0 | bus error or address error ? + bgt 1f | if >3 then normal exc +#if ( M68K_HAS_VBR == 1 ) + lea a1@(2*29),a0 +#else + lea a1@(8),a0 | skip extra stuff + lea a0@(6),a0 | a0 = orig sp +#endif +1: + movew a1@(SR_OFFSET),d1 | d1 = sr + andl #0xffff,d1 + lea a7@(-76),a7 | reserve room for exception frame +| build CPU_Exception_frame + movel d0,a7@ | vecnum + movel d1,a7@(4) | sr + movel a1@(PC_OFFSET),d1 | d1 = pc + cmpiw #47,d0 | trap #15, breakpoint? + bne 2f + subql #2,d1 | real PC is at trap insn +2: movel d1,a7@(8) | store pc to exframe struct + movel a7@(76),a7@(12) | the orig d0 pushed at beginning + movel a7@(76+4),a7@(16) | the orig d1 pushed at beginning + movel d2,a7@(20) + movel d3,a7@(24) + movel d4,a7@(28) + movel d5,a7@(32) + movel d6,a7@(36) + movel d7,a7@(40) + movel a7@(76+8),a7@(44) | the orig a0 pushed at beginning + movel a7@(76+12),a7@(48) | the orig a1 pushed at beginning + movel a2,a7@(52) + movel a3,a7@(56) + movel a4,a7@(60) + movel a5,a7@(64) + movel a6,a7@(68) + movel a0,a7@(72) | stack pointer before exception + lea a7@,a0 | exframe address + movel a1,a7@- | save top of orig frame + movel a0,a7@- | push exframe address + jsr SYM(BreakPointExcHdl) + addql #4,a7 | pop exframe address + movel a7@+,a1 | restore orig frame address +| XXX what should be restored from exframe?? + movel a7@(4),d1 | sr + movew d1,a1@(SR_OFFSET) | store sr to frame XXX ??? + movel a7@(8),a1@(PC_OFFSET) | store pc to frame XXX ??? + movel a7@(12),a7@(76) | d0 to be restored from stack + movel a7@(16),a7@(76+4) | d1 to be restored from stack + movel a7@(20),d2 + movel a7@(24),d3 + movel a7@(28),d4 + movel a7@(32),d5 + movel a7@(36),d6 + movel a7@(40),d7 + movel a7@(44),a7@(76+8) | a0 to be restored from stack + movel a7@(48),a7@(76+12) | a1 to be restored from stack + movel a7@(52),a2 + movel a7@(56),a3 + movel a7@(60),a4 + movel a7@(64),a5 + movel a7@(68),a6 + addl #76,a7 | pop exframe + +#if ( M68K_COLDFIRE_ARCH == 0 ) + moveml a7@+,d0-d1/a0-a1 | restore d0-d1,a0-a1 +#else + moveml a7@,d0-d1/a0-a1 | restore d0-d1,a0-a1 + lea a7@(16),a7 +#endif + +#if ( M68K_HAS_VBR == 0 ) + addql #2,a7 | pop format/id +#endif /* M68K_HAS_VBR */ + +| XXX bus err cleanup + + rte + +END_CODE + +END |