diff options
Diffstat (limited to 'private/mvdm/softpc.new/base/ccpu386/enter.c')
| -rw-r--r-- | private/mvdm/softpc.new/base/ccpu386/enter.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/private/mvdm/softpc.new/base/ccpu386/enter.c b/private/mvdm/softpc.new/base/ccpu386/enter.c new file mode 100644 index 000000000..8d6feac59 --- /dev/null +++ b/private/mvdm/softpc.new/base/ccpu386/enter.c @@ -0,0 +1,199 @@ +/*[ + +enter.c + +LOCAL CHAR SccsID[]="@(#)enter.c 1.7 01/19/95"; + +ENTER CPU functions. +-------------------- + +]*/ + + +#include <insignia.h> + +#include <host_def.h> +#include <xt.h> +#include <c_main.h> +#include <c_addr.h> +#include <c_bsic.h> +#include <c_prot.h> +#include <c_seg.h> +#include <c_stack.h> +#include <c_xcptn.h> +#include <c_reg.h> +#include <enter.h> +#include <c_page.h> +#include <fault.h> + + +/* + ===================================================================== + EXTERNAL ROUTINES STARTS HERE. + ===================================================================== + */ + + +GLOBAL VOID +ENTER16 + +IFN2( + IU32, op1, /* immediate data space required */ + IU32, op2 /* level (indicates parameters which must be copied) */ + ) + + + { + IU32 frame_ptr; + + IS32 p_delta = 0; /* posn of parameter relative to BP */ + IU32 p_addr; /* memory address of parameter */ + IU32 param; /* parameter read via BP */ + + op2 &= 0x1f; /* take level MOD 32 */ + + /* check room on stack for new data */ + validate_stack_space(USE_SP, (ISM32)op2+1); + + /* check old parameters exist */ + if ( op2 > 1 ) + { + /* + BP is pointing to the old stack before the parameters + were actually pushed, we therefore test for the presence + of the parameters by seeing if they could have been pushed, + if so they exist now. + + We have to take care of the READ/WRITE stack addressability + ourselves. Because we have checked the new data can be + written we know the next call can not fail because of access + problems, however we don't yet know if the stack is readable. + + Note we have been a bit severe on the paging unit because we + are asking if the old parameters could be written, if so they + can certainly be read from the point of view of the paging + unit! + */ + /* do access check */ + if ( GET_SS_AR_R() == 0 ) + SF((IU16)0, FAULT_ENTER16_ACCESS); + + /* now we know 'frigged' limit check is ok */ + validate_stack_space(USE_BP, (ISM32)op2-1); + } + + /* all ok - process instruction */ + + spush((IU32)GET_BP()); /* push BP */ + frame_ptr = GetStackPointer(); /* save (E)SP */ + + if ( op2 > 0 ) + { + /* level is >=1, copy stack parameters if they exist */ + while ( --op2 > 0 ) + { + /* copy parameter */ + p_delta -= 2; /* decrement to next parameter */ + + /* calculate parameter address in 32/16bit arithmetic */ + p_addr = get_current_BP() + p_delta; + if ( GET_SS_AR_X() == 0 ) /* look at SS 'B' bit */ + p_addr &= WORD_MASK; + + p_addr += GET_SS_BASE(); + + param = (IU32)vir_read_word(p_addr, NO_PHYSICAL_MAPPING); + spush(param); + } + spush((IU32)frame_ptr); /* save old (E)SP */ + } + + /* update (E)BP */ + set_current_BP(frame_ptr); + + /* finally allocate immediate data space on stack */ + if ( op1 ) + byte_change_SP((IS32)-op1); + } + +GLOBAL VOID +ENTER32 + +IFN2( + IU32, op1, /* immediate data space required */ + IU32, op2 /* level (indicates parameters which must be copied) */ + ) + + + { + IU32 frame_ptr; + + IS32 p_delta = 0; /* posn of parameter relative to EBP */ + IU32 p_addr; /* memory address of parameter */ + IU32 param; /* parameter read via EBP */ + + op2 &= 0x1f; /* take level MOD 32 */ + + /* check room on stack for new data */ + validate_stack_space(USE_SP, (ISM32)op2+1); + + /* check old parameters exist */ + if ( op2 > 1 ) + { + /* + EBP is pointing to the old stack before the parameters + were actually pushed, we therefore test for the presence + of the parameters by seeing if they could have been pushed, + if so they exist now. + + We have to take care of the READ/WRITE stack addressability + ourselves. Because we have checked the new data can be + written we know the next call can not fail because of access + problems, however we don't yet know if the stack is readable. + + Note we have been a bit severe on the paging unit because we + are asking if the old parameters could be written, if so they + can certainly be read from the point of view of the paging + unit! + */ + /* do access check */ + if ( GET_SS_AR_R() == 0 ) + SF((IU16)0, FAULT_ENTER32_ACCESS); + + /* now we know 'frigged' limit check is ok */ + validate_stack_space(USE_BP, (ISM32)op2-1); + } + + /* all ok - process instruction */ + + spush((IU32)GET_EBP()); /* push EBP */ + frame_ptr = GetStackPointer(); /* save (E)SP */ + + if ( op2 > 0 ) + { + /* level is >=1, copy stack parameters if they exist */ + while ( --op2 > 0 ) + { + /* copy parameter */ + p_delta -= 4; /* decrement to next parameter */ + + /* calculate parameter address in 32/16bit arithmetic */ + p_addr = get_current_BP() + p_delta; + if ( GET_SS_AR_X() == 0 ) /* look at SS 'B' bit */ + p_addr &= WORD_MASK; + + p_addr += GET_SS_BASE(); + + param = (IU32)vir_read_dword(p_addr, NO_PHYSICAL_MAPPING); + spush(param); + } + spush((IU32)frame_ptr); /* save old (E)SP */ + } + + /* update (E)BP */ + set_current_BP(frame_ptr); + + /* finally allocate immediate data space on stack */ + if ( op1 ) + byte_change_SP((IS32)-op1); + } |