diff options
Diffstat (limited to 'kernel/arch/m68k/fpsp040/x_fline.S')
| -rw-r--r-- | kernel/arch/m68k/fpsp040/x_fline.S | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/kernel/arch/m68k/fpsp040/x_fline.S b/kernel/arch/m68k/fpsp040/x_fline.S new file mode 100644 index 000000000..264e126d1 --- /dev/null +++ b/kernel/arch/m68k/fpsp040/x_fline.S @@ -0,0 +1,103 @@ +| +| x_fline.sa 3.3 1/10/91 +| +| fpsp_fline --- FPSP handler for fline exception +| +| First determine if the exception is one of the unimplemented +| floating point instructions. If so, let fpsp_unimp handle it. +| Next, determine if the instruction is an fmovecr with a non-zero +| <ea> field. If so, handle here and return. Otherwise, it +| must be a real F-line exception. +| + +| Copyright (C) Motorola, Inc. 1990 +| All Rights Reserved +| +| For details on the license for this file, please see the +| file, README, in this same directory. + +X_FLINE: |idnt 2,1 | Motorola 040 Floating Point Software Package + + |section 8 + +#include "fpsp.h" + + |xref real_fline + |xref fpsp_unimp + |xref uni_2 + |xref mem_read + |xref fpsp_fmt_error + + .global fpsp_fline +fpsp_fline: +| +| check for unimplemented vector first. Use EXC_VEC-4 because +| the equate is valid only after a 'link a6' has pushed one more +| long onto the stack. +| + cmpw #UNIMP_VEC,EXC_VEC-4(%a7) + beql fpsp_unimp + +| +| fmovecr with non-zero <ea> handling here +| + subl #4,%a7 |4 accounts for 2-word difference +| ;between six word frame (unimp) and +| ;four word frame + link %a6,#-LOCAL_SIZE + fsave -(%a7) + moveml %d0-%d1/%a0-%a1,USER_DA(%a6) + moveal EXC_PC+4(%a6),%a0 |get address of fline instruction + leal L_SCR1(%a6),%a1 |use L_SCR1 as scratch + movel #4,%d0 + addl #4,%a6 |to offset the sub.l #4,a7 above so that +| ;a6 can point correctly to the stack frame +| ;before branching to mem_read + bsrl mem_read + subl #4,%a6 + movel L_SCR1(%a6),%d0 |d0 contains the fline and command word + bfextu %d0{#4:#3},%d1 |extract coprocessor id + cmpib #1,%d1 |check if cpid=1 + bne not_mvcr |exit if not + bfextu %d0{#16:#6},%d1 + cmpib #0x17,%d1 |check if it is an FMOVECR encoding + bne not_mvcr +| ;if an FMOVECR instruction, fix stack +| ;and go to FPSP_UNIMP +fix_stack: + cmpib #VER_40,(%a7) |test for orig unimp frame + bnes ck_rev + subl #UNIMP_40_SIZE-4,%a7 |emulate an orig fsave + moveb #VER_40,(%a7) + moveb #UNIMP_40_SIZE-4,1(%a7) + clrw 2(%a7) + bras fix_con +ck_rev: + cmpib #VER_41,(%a7) |test for rev unimp frame + bnel fpsp_fmt_error |if not $40 or $41, exit with error + subl #UNIMP_41_SIZE-4,%a7 |emulate a rev fsave + moveb #VER_41,(%a7) + moveb #UNIMP_41_SIZE-4,1(%a7) + clrw 2(%a7) +fix_con: + movew EXC_SR+4(%a6),EXC_SR(%a6) |move stacked sr to new position + movel EXC_PC+4(%a6),EXC_PC(%a6) |move stacked pc to new position + fmovel EXC_PC(%a6),%FPIAR |point FPIAR to fline inst + movel #4,%d1 + addl %d1,EXC_PC(%a6) |increment stacked pc value to next inst + movew #0x202c,EXC_VEC(%a6) |reformat vector to unimp + clrl EXC_EA(%a6) |clear the EXC_EA field + movew %d0,CMDREG1B(%a6) |move the lower word into CMDREG1B + clrl E_BYTE(%a6) + bsetb #UFLAG,T_BYTE(%a6) + moveml USER_DA(%a6),%d0-%d1/%a0-%a1 |restore data registers + bral uni_2 + +not_mvcr: + moveml USER_DA(%a6),%d0-%d1/%a0-%a1 |restore data registers + frestore (%a7)+ + unlk %a6 + addl #4,%a7 + bral real_fline + + |end |