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Text File | 1992-01-04 | 33.7 KB | 1,516 lines

PAGE 58,132 ;****************************************************************************** TITLE combuff.asm - ;****************************************************************************** ; ; (C) Copyright MICROSOFT Corp. All Rights Reserved, 1989, 1990 ; ; Title: combuff.asm - ; ; Version: 1.00 ; ; Date: 30-Jan-1990 ; ; Author: RAL ; ;------------------------------------------------------------------------------ ; ; Change log: ; ; DATE REV DESCRIPTION ; ----------- --- ----------------------------------------------------------- ; 30-Jan-1990 RAL Original ; 31-Jan-1990 RAL Added support for XON/XOFF protocol ; 13-Feb-1990 RAP Check for version 3.00 of VCD in Sys_Critical_Init ; ;============================================================================== ; ; DESCRIPTION: ; This device is responsible for buffering COM I/O. It is closely ; tied to the Virtual COM Device. See the VCD documentation for ; details. ; ;****************************************************************************** .386p ;****************************************************************************** ; I N C L U D E S ;****************************************************************************** .XLIST INCLUDE VMM.Inc INCLUDE Debug.Inc INCLUDE VPICD.inc INCLUDE VCD.Inc .LIST ;****************************************************************************** ; V I R T U A L D E V I C E D E C L A R A T I O N ;****************************************************************************** Declare_Virtual_Device COMBUFF, 1, 0, COMBuff_Control ;****************************************************************************** ; E Q U A T E S ;****************************************************************************** CB_No_Proto EQU 0 CB_XOFF_Proto EQU 1 XOFF_Char EQU 13h Default_Buf_Size EQU 128 ;****************************************************************************** ; S T R U C T U R E S ;****************************************************************************** COMBuff_Extended_COM_Struc STRUC Filler db SIZE VCD_COM_Struc dup (?) VCD_Vier db ? ; Virtual Interrupt Enable register VCD_Vlcr db ? ; Virtual Line Control register VCD_Vmcr db ? ; Virtual Modem Control register VCD_Viir db ? ; Virtual Interrupt Identity register VCD_Vlsr db ? ; Virtual Line status register VCD_Vrxb db ? ; Virtual Rx Buffer VCD_Vmsr db 0 ; Virtual Modem status register VCD_Virr db 0 ; Virtual Interrupt Request register VCD_XOFF_Flag db 0 VCD_Protocol db ? IFDEF DEBUG VCD_Max_Queued dw ? ; max # of chars ever queued ENDIF VCD_RxQin dw 0 ; First In... VCD_RxQout dw 0 ; ...First Out VCD_RxQcount dw 0 ; How many in queue VCD_RxQlen dw ? ; Total size of queue in VCD_RxQ dw ? ; QUEUE STARTS HERE -- Continues past here COMBuff_Extended_COM_Struc ENDS .errnz SIZE COMBuff_Extended_COM_Struc - VCD_RxQ - 2 ; ; Compute extra size of data area EXCLUDING the word used for the first ; queue entry (total queue size will be added on later). ; COMBuff_Extra_Data_Area = SIZE COMBuff_Extended_COM_Struc-SIZE VCD_COM_Struc-2 ;****************************************************************************** ; F L A G E Q U A T E S ;****************************************************************************** ;****************************************************************************** ; I N I T I A L I Z A T I O N D A T A ;****************************************************************************** VxD_IDATA_SEG EXTRN COMBuff_Size_Ini_String:BYTE EXTRN COMBuff_Size_Ini_Number:BYTE EXTRN COMBuff_Prot_Ini_String:BYTE EXTRN COMBuff_Prot_Ini_Number:BYTE EXTRN COMBuff_XOFF_String:BYTE VxD_IDATA_ENDS ;****************************************************************************** ; L O C A L D A T A ;****************************************************************************** VxD_DATA_SEG COMBuff_ProcList LABEL DWORD dd OFFSET32 COMBuff_VCD_Control dd OFFSET32 COMBuff_Int dd 0 dd OFFSET32 COMBuff_EOI dd OFFSET32 COMBuff_Mask dd OFFSET32 COMBuff_Test_Int_Req dd OFFSET32 COMBuff_In_RxTxB dd OFFSET32 COMBuff_Out_RxTxB dd OFFSET32 COMBuff_In_IER dd OFFSET32 COMBuff_Out_IER dd OFFSET32 COMBuff_In_IIR dd OFFSET32 COMBuff_Out_IIR dd OFFSET32 COMBuff_In_LCR dd OFFSET32 COMBuff_Out_LCR dd OFFSET32 COMBuff_In_MCR dd OFFSET32 COMBuff_Out_MCR dd OFFSET32 COMBuff_In_LSR dd OFFSET32 COMBuff_Out_LSR dd OFFSET32 COMBuff_In_MSR dd OFFSET32 COMBuff_Out_MSR .ERRNZ $-COMBuff_ProcList-SIZE VCD_ProcList_Struc IFDEF DEBUG COM1_Handle dd 0 COM2_Handle dd 0 COM3_Handle dd 0 COM4_Handle dd 0 ENDIF VxD_DATA_ENDS ;****************************************************************************** ; D E V I C E C O N T R O L P R O C E D U R E ;****************************************************************************** VxD_CODE_SEG ;****************************************************************************** ; ; COMBuff_Control ; ; DESCRIPTION: ; This is the device control procedure for the COM Buffer device. ; ; ENTRY: ; EAX = Control call ID ; ; EXIT: ; If carry clear then ; Successful ; else ; Control call failed ; ; USES: ; EAX, EBX, ECX, EDX, ESI, EDI, Flags ; ;============================================================================== BeginProc COMBuff_Control Control_Dispatch Sys_Critical_Init, COMBuff_Sys_Crit_Init IFDEF DEBUG Control_Dispatch Debug_Query, COMBuff_Debug_Query ENDIF clc ; Ignore other control calls ret EndProc COMBuff_Control VxD_CODE_ENDS ;****************************************************************************** ; I N I T I A L I Z A T I O N C O D E ;****************************************************************************** VxD_ICODE_SEG ;****************************************************************************** ; ; COMBuff_Sys_Crit_Init ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_Sys_Crit_Init VxDCall VCD_Get_Version cmp eax, 300h jb fail_init xor ecx, ecx CB_SCI_Loop: inc ecx push ecx lea eax, [ecx+"0"] mov [COMBuff_Size_Ini_Number], al mov [COMBuff_Prot_Ini_Number], al mov eax, Default_Buf_Size xor esi, esi ; Null default program name mov edi, OFFSET32 COMBuff_Size_Ini_String VMMcall Get_Profile_Decimal_Int test eax, eax jz DEBFAR CB_SCI_No_Buffer cmp eax, 10000 jb SHORT CB_SCI_Reasonable_Size Debug_Out "Silly size of #EAX for COM buffer ignored -- Using a 10K buffer" mov eax, 10000 CB_SCI_Reasonable_Size: push eax push ecx xchg eax, ecx ; EAX = Port #, ECX=Queue len mov ebx, COM_IRQ_Sharable add ecx, ecx ; 2 bytes per queue entry add ecx, COMBuff_Extra_Data_Area ; Add in size of data struc xor edx, edx mov esi, OFFSET32 COMBuff_ProcList VxDcall VCD_Virtualize_Port mov ebx, eax pop ecx pop eax jc SHORT CB_SCI_No_Buffer IFDEF DEBUG ; save COM handle push esi mov esi, ecx dec esi mov [esi*4][COM1_Handle], ebx pop esi ENDIF mov [ebx.VCD_RxQlen], ax ; Remember queue size xor edx, edx xor esi, esi ; Null default program name mov edi, OFFSET32 COMBuff_Prot_Ini_String VMMcall Get_Profile_String mov [ebx.VCD_Protocol], CB_No_Proto test edx, edx jz SHORT CB_SCI_Next_Port mov esi, OFFSET32 COMBuff_XOFF_String mov edi, edx call Compare_Strings jc SHORT CB_SCI_Next_Port mov [ebx.VCD_Protocol], CB_XOFF_Proto CB_SCI_Next_Port: CB_SCI_No_Buffer: pop ecx cmp ecx, 4 jb CB_SCI_Loop clc fail_init: ret EndProc COMBuff_Sys_Crit_Init ;****************************************************************************** ; ; Compare_Strings ; ; DESCRIPTION: ; This procedure compares two strings. If all of the characters up ; to the NULL terminator of the first string match the characters ; of the second string the procedure returns with carry clear, ; otherwise carry is set. On exit ECX contains the OFFSET of the ; character that did not match. Othewise it contains the length of ; the first string (NOT including the NULL terminator). ; ; ENTRY: ; ESI = pointer to ASCIIZ string ; EDI = pointer to String (does not have to be null terminated) ; ; EXIT: ; Carry clear if strings matched. ; ; USES: ; Flags ; ;============================================================================== BeginProc Compare_Strings pushad xor ecx, ecx cld CS_Loop: lodsb test al, al jz SHORT CS_Match call Force_Upper_Case mov bl, al mov al, BYTE PTR [edi] inc edi call Force_Upper_Case cmp al, bl jne SHORT CS_Failed inc ecx jmp CS_Loop CS_Failed: stc jmp SHORT CS_Exit CS_Match: clc CS_Exit: popad ret EndProc Compare_Strings ;****************************************************************************** ; ; Force_Upper_Case ; ; DESCRIPTION: ; This routine takes an ASCII character in AL and, if it is a lower ; case letter, converts it to upper case. ; ; ENTRY: ; AL = ASCII character ; ; EXIT: ; AL = upper case letter or other ASCII character(unchanged) ; ; USES: ; ;============================================================================== BeginProc Force_Upper_Case cmp al, "a" jb SHORT FUC_Done cmp al, "z" ja SHORT FUC_Done sub al, "a"-"A" FUC_Done: ret EndProc Force_Upper_Case VxD_ICODE_ENDS ;------------------------------------------------------------------------------ VxD_CODE_SEG ;****************************************************************************** ; P R O C F O R C O N T R O L C A L L S F R O M V C D ;****************************************************************************** ;****************************************************************************** ; ; COMBuff_VCD_Control ; ; DESCRIPTION: ; ; ENTRY: ; EAX = message ; EBX = new VM, or 0 ; EDX = old VM, or 0 ; ESI -> COM Struc ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_VCD_Control cmp eax, VCD_Control_Set_Owner jne SHORT COMBuff_VC_Ignore xchg ebx, edx or ebx, ebx ;Q: non-zero old VM handle jz SHORT CB_no_int_req ; N: mov eax, [esi.VCD_IRQ_Handle] ; Y: check about clearing ; any outstanding int request or eax, eax jz short CB_no_int_req VxDCall VPICD_Get_Complete_Status test ecx, VPICD_Stat_Virt_Dev_Req ;Q: we requested int? jz SHORT CB_no_int_req ; N: VxDCall VPICD_Clear_Int_Request ; Y: clear int request CB_no_int_req: mov ebx, edx test ebx, ebx ;Q: assigning a new VM jz SHORT COMBuff_VC_Ignore ; N: call COMBuff_Clear_Queue mov eax, [esi.VCD_IRQ_Handle] or eax, eax jz short @F VxDCall VPICD_Get_Complete_Status test ecx, VPICD_Stat_Virt_Mask ;Q: VM has IRQ masked? jz short VC_not_masked ; N: @@: call COMBuff_Disable_Trapping ; Y: disable port trapping VC_not_masked: lea edi, [esi.VCD_Vier] mov esi, [esi.VCD_CB_Offset] lea esi, [esi][ebx.VCD_IER] cld movsw ; Copy IER and LCR movsb ; Copy MCR COMBuff_VC_Ignore: clc ret EndProc COMBuff_VCD_Control ;****************************************************************************** ; I / O T R A P P R O C E D U R E S ;****************************************************************************** ;****************************************************************************** ; ; COMBuff_In_RxTxB ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_In_RxTxB, High_Freq cli test [esi.VCD_Vlcr], LCR_DLAB ; Q: Access is to Divisor latch? jnz SHORT CB_In_Divisor_Latch ; Y: Yes, go do it ; ; Input from data buffer ; mov al, [esi.VCD_Vrxb] ; Get current character and [esi.VCD_Vlsr], NOT LSR_DR ; Preserve error bits, reset DR and [esi.VCD_Virr], NOT IER_DR ; Clear DR virtual interrupt call COMBuff_Extract_Queue ; Suck out new status/char IFDEF DEBUG_XOFF push eax and al, 7Fh cmp al, XOFF_char jne short D01_not_xoff mov al, [esi.VCD_Number] Trace_Out 'XOFF read on COM#al' D01_not_xoff: pop eax ENDIF sti ret ; ; Input from divisor latch LSB -- No virtualization ; CB_In_Divisor_Latch: in al, dx sti ret EndProc COMBuff_In_RxTxB ;****************************************************************************** ; ; COMBuff_Out_RxTxB ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_Out_RxTxB, High_Freq cli test [esi.VCD_Vlcr], LCR_DLAB ; Q: Access is to Divisor latch? jnz SHORT CB_Out_Divisor_Latch ; Y: Yes, go do it and [esi.VCD_Virr], NOT IER_THRE ; Write to THR clears interrupt cmp al, XOFF_Char ; Q: Is this a Ctrl-S je SHORT CB_THR_Sent_XOFF ; Y: Force delay cmp [esi.VCD_XOFF_Flag], True ; N: Q: Delaying now? je SHORT CB_THR_Restart ; Y: Stop delay now ; N: Just send char CB_Out_Divisor_Latch: out dx, al ; Do ouput sti ret ; ; Some other character was ; CB_THR_Restart: mov [esi.VCD_XOFF_Flag], False push eax push edx call COMBuff_Extract_Queue call COMBuff_Test_Int_Req pop edx pop eax out dx, al sti ret CB_THR_Sent_XOFF: cmp [esi.VCD_Protocol], CB_XOFF_Proto jne SHORT CB_THR_Output_Byte mov [esi.VCD_XOFF_Flag], True CB_THR_Output_Byte: out dx, al sti ret EndProc COMBuff_Out_RxTxB ;****************************************************************************** ; ; COMBuff_In_IER ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_In_IER, High_Freq cli test [esi.VCD_Vlcr], LCR_DLAB ; Q: Access is to divisor latch jnz CB_In_Divisor_Latch ; Y: Do input from port mov al, [esi.VCD_Vier] ; return virtual reg sti ret EndProc COMBuff_In_IER ;****************************************************************************** ; ; COMBuff_Out_IER ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_Out_IER cli test [esi.VCD_Vlcr], LCR_DLAB ; Q: Access is to divisor latch jnz CB_Out_Divisor_Latch ; Y: Do output to port xchg al, [esi.VCD_Vier] ; What the VM thought it was out dx, al ; Make sure HW sees change IO_Delay ; Give hardware lots of time mov al, [esi.VCD_Vier] ; Recover what the VM wants or al, IER_DR ; Make sure we get Rx ints! out dx, al ; Set it... sti ret EndProc COMBuff_Out_IER ;****************************************************************************** ; ; COMBuff_In_IIR ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== VxD_DATA_SEG ; ; Table to translate enabled active interrupts to IIR value ; ( see VCD_Trap_IIR ) ; COMBuff_IIR_Table LABEL BYTE db IIR_NONE ; 0 0 0 0 db IIR_DR ; 0 0 0 1 db IIR_THRE ; 0 0 1 0 db IIR_DR ; 0 0 1 1 db IIR_LS ; 0 1 0 0 db IIR_LS ; 0 1 0 1 db IIR_LS ; 0 1 1 0 db IIR_LS ; 0 1 1 1 db IIR_MS ; 1 0 0 0 db IIR_DR ; 1 0 0 1 db IIR_THRE ; 1 0 1 0 db IIR_DR ; 1 0 1 1 db IIR_LS ; 1 1 0 0 db IIR_LS ; 1 1 0 1 db IIR_LS ; 1 1 1 0 db IIR_LS ; 1 1 1 1 VxD_DATA_ENDS BeginProc COMBuff_In_IIR cli movzx eax, [esi.VCD_Virr] ; Interrupts requested and al, [esi.VCD_Vier] ; Interrupts enabled and al, 1111b ; Make sure only low nibble mov al, COMBuff_IIR_Table[eax] ; Pick up value from table cmp al, IIR_THRE ; Q: Strange one? je SHORT CB_In_IIR_Reset_THRE ; Y: Must reset THRE sti ret CB_In_IIR_Reset_THRE: and [esi.VCD_Virr], NOT IER_THRE ; not pending any more sti ret EndProc COMBuff_In_IIR ;****************************************************************************** ; ; COMBuff_Out_IIR ; ; DESCRIPTION: ; This procedure should normally not be called! ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_Out_IIR mov [esi.VCD_Viir], al ret EndProc COMBuff_Out_IIR ;****************************************************************************** ; ; COMBuff_In_LCR ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_In_LCR cli mov al, [esi.VCD_Vlcr] ; no point worrying device sti ret EndProc COMBuff_In_LCR ;****************************************************************************** ; ; COMBuff_Out_LCR ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_Out_LCR cli mov [esi.VCD_Vlcr], al ; Output: save it for DLAB sti out dx, al ; and do it. ret EndProc COMBuff_Out_LCR ;****************************************************************************** ; ; COMBuff_In_MCR ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_In_MCR cli mov al, [esi.VCD_Vmcr] ; no point worrying device sti ret EndProc COMBuff_In_MCR ;****************************************************************************** ; ; COMBuff_Out_MCR ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_Out_MCR cli xchg al, [esi.VCD_Vmcr] ; Get what the VM thought it was out dx, al ; This may disable interrupt! IO_Delay ; Give hardware lots of time mov al, [esi.VCD_Vmcr] ; Get what the VM wants or al, MCR_INTEN ; Assume we want to enable ints out dx, al ; and do it. test al, MCR_DTR ; Q: Is DTR is on? jz COMBuff_Clear_Queue ; N: Clear queue & return sti ret ; Y: Done! EndProc COMBuff_Out_MCR ;****************************************************************************** ; ; COMBuff_In_LSR ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_In_LSR, High_Freq cli in al, dx ; Get real status test al, (LSR_DR + LSR_ERRBITS) ; any Rx status? jz short VCD_Trap_LSR_Got_Status ; no, nothing to do push eax and al, (LSR_DR + LSR_ERRBITS) ; junk transmit status call COMBuff_Poll_Status ; Deal with Rx status pop eax ; (ax got splattered!) and al, LSR_TXBITS ; Real Tx status VCD_Trap_LSR_Got_Status: mov bl, [esi.VCD_Vlsr] ; get virtual Rx status or al, bl ; plus real Tx status and bl, LSR_DR ; preserve DR bit, clear error mov [esi.VCD_Vlsr], bl ; bits when reading LSR and [esi.VCD_Virr], NOT IER_LS ; clear interrupt request sti ret EndProc COMBuff_In_LSR ;****************************************************************************** ; ; COMBuff_Out_LSR ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_Out_LSR cli and al, (LSR_DR + LSR_ERRBITS) ; what the chip does! mov [esi.VCD_Vlsr], al ; weird! ; Emulate the H/W.... and [esi.VCD_Virr], NOT (IER_LS + IER_DR) test al, LSR_DR jz SHORT CB_LSR_NoDR or [esi.VCD_Virr], IER_DR CB_LSR_NoDr: test al, LSR_ERRBITS jz SHORT CB_LSR_Exit or [esi.VCD_Virr], IER_LS CB_LSR_Exit: sti ret EndProc COMBuff_Out_LSR ;****************************************************************************** ; ; COMBuff_In_MSR ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_In_MSR cli in al, dx ; get real status or al, [esi.VCD_Vmsr] ; and any saved delta bits mov [esi.VCD_Vmsr], 0 and [esi.VCD_Virr], NOT IER_MS ; clear modem interrupt request sti ret EndProc COMBuff_In_MSR ;****************************************************************************** ; ; COMBuff_Out_MSR ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_Out_MSR cli out dx, al ; do it! mov [esi.VCD_Vmsr], 0 ; No saved delta bits now! sti ret EndProc COMBuff_Out_MSR ;****************************************************************************** ; H A R D W A R E I N T E R R U P T P R O C E D U R E S ;****************************************************************************** ;****************************************************************************** ; ; COMBuff_Int ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== VxD_DATA_SEG CB_Int_Jmp_Table LABEL DWORD dd OFFSET32 CB_Modem_Int dd OFFSET32 CB_THRE_Int dd OFFSET32 CB_Rx_Int dd OFFSET32 CB_Rx_Int VxD_DATA_ENDS BeginProc COMBuff_Int, High_Freq mov edx, [esi.VCD_IObase] ; Get start of ports add dx, UART_IIR in al, dx ; get interrupt identity test al, IIR_NONE ; Came from this device? jz SHORT CB_Int_Jump ; Yep, jump to handler ; Nope - Reflect it stc ; to next guy in chain ret CB_Int_Loop: mov edx, [esi.VCD_IObase] ; Get start of ports add dx, UART_IIR in al, dx ; Get interrupt identity test al, IIR_NONE ; Came from this device? jnz SHORT CB_Int_Done ; nope, just return! CB_Int_Jump: IFDEF DEBUG test al, NOT 07h jz short CB_IIR_Okay Debug_Out "COMBUF: IIR (#DX) has too many bits set: #AL" CB_IIR_Okay: ENDIF and al, 07h movzx eax, al jmp CB_Int_Jmp_Table[eax*2] ; Go deal with it CB_Modem_Int: add dx, (UART_MSR - UART_IIR) ; pick up current modem status in al, dx and al, MSR_DELTA ; only want Delta bits mov [esi.VCD_Vmsr], al ; save in virtual MSR or [esi.VCD_Virr], IER_MS ; set modem interrupt request jmp CB_Int_Loop CB_THRE_Int: or [esi.VCD_Virr], IER_THRE ; set THRE interrupt request jmp CB_Int_Loop CB_Rx_Int: add dx, (UART_LSR - UART_IIR) ; yes, get character/status in al, dx and al, (LSR_DR + LSR_ERRBITS) ; junk transmit status jz CB_Int_Loop ; Hmmm! call COMBuff_Poll_Status jmp CB_Int_Loop CB_Int_Done: mov eax, [esi.VCD_IRQ_Handle] VxDcall VPICD_Phys_EOI call COMBuff_Extract_Queue call COMBuff_Test_Int_Req ; Will "return" for us clc ret EndProc COMBuff_Int ;****************************************************************************** ; ; COMBuff_EOI ; ; DESCRIPTION: ; Here we mindlessly clear the interrupt request for the COM port ; since it dosen't matter if the buffer was serviced yet or not. ; If it was not, then the IRET procedure will set the int request ; again and everyon will still be happy. ; ; ENTRY: ; EAX = IRQ handle ; EBX = Current VM handle ; ESI -> COM structure ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_EOI, High_Freq VxDjmp VPICD_Clear_Int_Request EndProc COMBuff_EOI ;****************************************************************************** ; ; COMBuff_Mask ; ; DESCRIPTION: Routine called when VM is changing a COM port's IRQ mask ; ; ENTRY: EAX = IRQ handle ; EBX = VM handle ; ESI -> COM data structure ; ECX = 0, if unmasking ; ; EXIT: none ; ; USES: flags ; ;============================================================================== BeginProc COMBuff_Mask jecxz short COMBuff_Enable_Trapping VxDCall VPICD_Get_Complete_Status test ecx, VPICD_Stat_In_Service ;Q: IRQ in service? jz short COMBuff_Disable_Trapping ; N: disable port trapping ret ; Y: don't disable trapping EndProc COMBuff_Mask ;****************************************************************************** ; ; COMBuff_Disable_Trapping ; ; DESCRIPTION: Disable local trapping of a COM port's I/O ports ; ; ENTRY: ESI -> COM data structure ; ; EXIT: none ; ; USES: flags ; ;============================================================================== BeginProc COMBuff_Disable_Trapping pushad IFDEF DEBUG_verbose mov al, [esi.VCD_Number] Trace_Out 'COMBUFF - disabling trapping for COM#al' ENDIF mov edx, [esi.VCD_IObase] mov ecx, UART_PORTS @@: VMMcall Disable_Local_Trapping inc edx loopd @B popad ret EndProc COMBuff_Disable_Trapping ;****************************************************************************** ; ; COMBuff_Enable_Trapping ; ; DESCRIPTION: Enable local trapping of a COM port's I/O ports ; ; ENTRY: ESI -> COM data structure ; ; EXIT: none ; ; USES: flags ; ;============================================================================== BeginProc COMBuff_Enable_Trapping pushad IFDEF DEBUG_verbose mov al, [esi.VCD_Number] Trace_Out 'COMBUFF - enabling trapping for COM#al' ENDIF ; ; First read current state of IER, LCR & MCR ; mov edx, [esi.VCD_IObase] inc edx .errnz UART_IER-1 in al, dx mov [esi.VCD_Vier], al add dl, UART_LCR-UART_IER IO_Delay in al, dx mov [esi.VCD_Vlcr], al inc edx .errnz UART_MCR-UART_LCR-1 IO_Delay in al, dx mov [esi.VCD_Vmcr], al sub dl, UART_MCR mov ecx, UART_PORTS @@: VMMcall Enable_Local_Trapping inc edx loopd @B popad ret EndProc COMBuff_Enable_Trapping ;****************************************************************************** ; ; COMBuff_Test_Int_Req ; ; DESCRIPTION: ; ; ENTRY: ; ESI -> COM structure ; ; EXIT: ; ; USES: ; Flags ; ;============================================================================== BeginProc COMBuff_Test_Int_Req push eax push ebx push ecx mov ebx, [esi.VCD_Owner] ; EBX = Handle of port owner Assert_VM_Handle ebx ; Paranoia... mov cl, [esi.VCD_Virr] ; Interrupts pending and cl, [esi.VCD_Vier] ; and enabled? jz SHORT CB_IR_Exit ; N: Clear int request test [esi.VCD_Vlcr], LCR_DLAB ; Q: Access is to divisor latch jnz short CB_IR_Exit ; yes, can't send it! test [esi.VCD_Vmcr], MCR_INTEN ; and enabled? jz short CB_IR_Exit ; no, can't send it! mov eax, [esi.VCD_IRQ_Handle] ; EAX = IRQ handle for VPICD or eax, eax jz short CB_IR_Exit VxDcall VPICD_Get_Status test ecx, VPICD_Stat_IRET_Pending ; Q: Waiting for IRET? jnz SHORT CB_IR_Exit ; Y: Wait a little longer VxDcall VPICD_Set_Int_Request CB_IR_Exit: pop ecx pop ebx pop eax ret EndProc COMBuff_Test_Int_Req ;****************************************************************************** ; ; COMBuff_Poll_Status ; ; DESCRIPTION: ; Read the Line Status Register. Put Transmit status in ; vitual register, receive status in queue or virtual ; register as appropriate. ; ; ENTRY: ; AL = LSR Rx bits ; DX = LSR I/O port ; ESI = pointer to VCD_COM structure ; ; EXIT: ; ; USES: ; EAX, EBX, EDX ; ;============================================================================== BeginProc COMBuff_Poll_Status mov ah, al ; Save status in ah test ah, LSR_DR ; data ready? jz SHORT CB_NoRxChar ; no, don't bother reading add edx, (UART_RBR - UART_LSR) ; DX => Receive buffer in al, dx ; get character in al ;;;;;;;;;;;;;; DEBUGGING CODE WILL INSERT @ IF HARDWARE OVERFLOW ;;;;;;;;;; IFDEF DEBUG test ah, LSR_OE jz SHORT OkieDokie mov al, '@' and ah, NOT LSR_OE OkieDokie: ENDIF ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; IFDEF DEBUG_XOFF push eax and al, 7Fh cmp al, XOFF_Char jne short D00_not_xoff mov al, [esi.VCD_Number] Trace_Out 'Received XOFF on COM#al' D00_not_xoff: pop eax ENDIF CB_NoRxChar: mov bl, [esi.VCD_Vlsr] ; Set virtual regs test bl, LSR_DR ; Should we queue it? jnz SHORT COMBuff_Insert_Queue ; yes, put in queue cmp [esi.VCD_XOFF_Flag], True ; XOFF sent? je SHORT COMBuff_Insert_Queue ; yes, put in queue or bl, ah mov [esi.VCD_Vlsr], bl test ah, LSR_DR ; Data to put there? jz SHORT CB_Poll_Status_Ret ; no, don't bother mov [esi.VCD_Vrxb], al ; (should usually have DR on) or [esi.VCD_Virr], IER_DR ; Set DR interrupt request test bl, LSR_ERRBITS ; Error bits on? jnz SHORT CB_Poll_Set_Int_Status ; yes, go set interrupt CB_Poll_Status_Ret: ret CB_Poll_Set_Int_Status: or [esi.VCD_Virr], IER_LS ; Set LS interrupt request ret EndProc COMBuff_Poll_Status ;****************************************************************************** ; Q U E U E P R O C E D U R E S ;****************************************************************************** ;****************************************************************************** ; ; COMBuff_Insert_Queue ; ; DESCRIPTION: ; ; ENTRY: ; AH = Status byte, AL = Data byte ; ; EXIT: ; ; USES: ; EBX, EAX ; ;============================================================================== BeginProc COMBuff_Insert_Queue mov bx, [esi.VCD_RxQlen] cmp [esi.VCD_RxQcount], bx ; queue full? je SHORT CB_IQ_Full movzx ebx, [esi.VCD_RxQin] mov [esi.VCD_RxQ+ebx*2], ax ; into the queue inc [esi.VCD_RxQcount] inc ebx cmp bx, [esi.VCD_RxQlen] jb SHORT CB_IQ_Set_New_Len xor ebx, ebx CB_IQ_Set_New_Len: mov [esi.VCD_RxQin], bx ; put index back IFDEF DEBUG mov bx, [esi.VCD_RxQcount] cmp bx, [esi.VCD_Max_Queued] jbe short CB_not_max mov [esi.VCD_Max_Queued], bx CB_not_max: ENDIF ret CB_IQ_Full: movzx ebx, [esi.VCD_RxQin] or ah, LSR_OE ; simulate overrun error mov [esi.VCD_RxQ+ebx*2], ax ; into the queue ret EndProc COMBuff_Insert_Queue ;****************************************************************************** ; ; COMBuff_Extract_Queue ; ; DESCRIPTION: ; ; ENTRY: ; ESI -> COM data structure ; ; EXIT: ; ; USES: EBX, EDX ; ;============================================================================== BeginProc COMBuff_Extract_Queue, High_Freq cmp [esi.VCD_RxQcount], 0 ; Anything in queue? je SHORT CB_EQ_Exit ; no, nothing to extract cmp [esi.VCD_XOFF_Flag], True ; Q: XOFF? je SHORT CB_EQ_Exit ; Y: Don't fill buffer CB_EQ_Loop: test [esi.VCD_Vlsr], LSR_DR jnz SHORT CB_EQ_Exit dec [esi.VCD_RxQcount] movzx ebx, [esi.VCD_RxQout] mov dx, [esi.VCD_RxQ+ebx*2] ; get character from the queue inc ebx cmp bx, [esi.VCD_RxQlen] jb SHORT CB_EQ_Set_Out_Ptr xor ebx, ebx CB_EQ_Set_Out_Ptr: mov [esi.VCD_RxQout], bx ; put index back or dh, [esi.VCD_Vlsr] ; add in old status mov [esi.VCD_Vlsr], dh ; and set virtual LSR test dh, LSR_DR ; Was there data too? jz short CB_EQ_NoData mov [esi.VCD_Vrxb], dl ; yes, put in virtual reg or [esi.VCD_Virr], IER_DR ; and set interrupt request test dh, LSR_ERRBITS ; Line status interrupt? jz SHORT CB_EQ_Exit ; no, just return or [esi.VCD_Virr], IER_LS ; yes, set interrupt request jmp SHORT CB_EQ_Exit CB_EQ_NoData: cmp [esi.VCD_RxQcount], 0 ; queue empty? jne short CB_EQ_Loop ; no, continue until queue ; empty, or LSR_DR is set test dh, LSR_ERRBITS ; Line status interrupt? jz SHORT CB_EQ_Exit ; no, just return or [esi.VCD_Virr], IER_LS ; yes, set interrupt request CB_EQ_Exit: ret EndProc COMBuff_Extract_Queue ;****************************************************************************** ; ; COMBuff_Clear_Queue ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_Clear_Queue mov [esi.VCD_RxQcount], 0 ; Clear receive Q mov [esi.VCD_RxQin], 0 mov [esi.VCD_RxQout], 0 and [esi.VCD_Vlsr], NOT LSR_DR ; preserve error bits, reset DR and [esi.VCD_Virr], NOT IER_DR ; clear DR virtual interrupt mov [esi.VCD_XOFF_Flag], False ret EndProc COMBuff_Clear_Queue ;****************************************************************************** ; D E B U G G I N G C O D E ;****************************************************************************** IFDEF DEBUG ;****************************************************************************** ; ; COMBuff_Debug_Query ; ; DESCRIPTION: ; ; ENTRY: ; ; EXIT: ; ; USES: ; ;============================================================================== BeginProc COMBuff_Debug_Query pushad mov ecx, 4 mov al, 1 mov esi, OFFSET32 COM1_Handle dump_port_data: mov ebx, [esi] or ebx, ebx jz short debug_no_com_port movzx edx, [ebx.VCD_Max_Queued] movzx edi, [ebx.VCD_RxQlen] Trace_Out "COM#al: buffer size=#di, max queued=#dx" jmp short debug_next_port debug_no_com_port: Trace_Out "COM#al: no buffer assigned" debug_next_port: inc al add esi, 4 loop dump_port_data popad ret EndProc COMBuff_Debug_Query ENDIF VxD_CODE_ENDS END