mkinitrd-6_3_2/isolinux/serirq.inc

;; -----------------------------------------------------------------------
;;
;;   Copyright 2009 Intel Corporation; author: H. Peter Anvin
;;
;;   This program is free software; you can redistribute it and/or modify
;;   it under the terms of the GNU General Public License as published by
;;   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
;;   Boston MA 02111-1307, USA; either version 2 of the License, or
;;   (at your option) any later version; incorporated herein by reference.
;;
;; -----------------------------------------------------------------------

;;
;; serirq.inc
;;
;; Serial port IRQ code
;;
;; We don't know what IRQ, if any, we have, so map all of them...
;;

		section .text
		bits 16
		align 8

		section .bss
		alignb 8

%assign n 0
%rep 16
		section .text
serstub_irq %+ n :
		push dword [cs:oldirq %+ n]
		jmp short irq_common

		section .bss
oldirq %+ n	resd 1
%assign n n+1
%endrep

		section .text
irq_common:
		pushf
		push ax
		push dx
		mov dx,[cs:SerialPort]
		add dx,5			; DX -> LSR
		in al,dx
		test al,1			; Received data
		jnz .data
.done:
		pop dx
		pop ax
		popf
		retf				; Chain to next handler
.data:
		push es
		push di
		mov ax,aux_seg + (aux.serial >> 4)
		mov es,ax
		mov di,[cs:SerialHead]
.loop:
		mov dx,[cs:SerialPort]		; DX -> RDR
		in al,dx
		stosb
		mov ah,[cs:FlowIgnore]
		add dx,5			; DX -> LSR
		in al,dx
		push ax
		and al,ah
		cmp al,ah
		jne .drop
		and di,serial_buf_size-1	; Wrap around if necessary
		cmp di,[cs:SerialTail]		; Would this cause overflow?
		je .drop			; If so, just drop the data
		mov [cs:SerialHead],di
.drop:
		pop ax
		test al,1			; More data?
		jnz .loop
.full:
		pop di
		pop es
		jmp .done

		section .data
;
; SerialIRQPort will generally track SerialPort, but will be 0 when an
; IRQ service is not installed.
;
SerialIRQPort	dw 0			; Serial port w IRQ service
SerialHead	dw 0			; Head of serial port rx buffer
SerialTail	dw 0			; Tail of serial port rx buffer

		section .bss
IRQMask		resw 1			; PIC IRQ mask status

		section .text

sirq_install:
		pushad

		call sirq_cleanup

		; Save the old interrupt vectors
		mov si,4*08h
		mov di,oldirq0
		mov cx,8
		rep movsd
		mov si,4*70h
		mov cx,8
		rep movsd

		; Install new interrupt vectors
		mov di,4*08h
		mov cx,8
		mov eax,serstub_irq0
.pic0:
		stosd
		add ax,serstub_irq1 - serstub_irq0
		loop .pic0
		mov di,4*70h
		mov cx,8
.pic1:
		stosd
		add ax,serstub_irq1 - serstub_irq0
		loop .pic1

		mov bx,[SerialPort]
		mov [SerialIRQPort],bx

		lea dx,[bx+5]		; DX -> LCR
		mov al,03h		; Clear DLAB (should already be...)
		slow_out dx,al

		lea dx,[bx+1]		; DX -> IER
		mov al,1		; Enable receive interrupt
		slow_out dx,al

		;
		; Enable all ther interupt lines at the PIC.  Some BIOSes
		; only enable the timer interrupts and other interrupts
		; actively in use by the BIOS.
		;
		in al,0xA1		; Secondary PIC mask register
		mov ah,al
		in al,0x21		; Primary PIC mask register
		mov [IRQMask],ax

		io_delay

		xor ax,ax		; Remove all interrupt masks
		out 0x21,al
		out 0xA1,al

		popad
		ret

sirq_cleanup_nowipe:
		pushad
		push ds
		push es
		xor ax,ax
		mov ds,ax
		mov es,ax

		mov bx,[SerialIRQPort]
		and bx,bx
		jz .done

		lea dx,[bx+5]		; DX -> LCR
		mov al,03h		; Clear DLAB (should already be...)
		slow_out dx,al

		lea dx,[bx+1]		; DX -> IER
		xor ax,ax
		slow_out dx,al		; Clear IER

		; Restore PIC masks
		mov ax,[IRQMask]
		out 0x21,al
		mov al,ah
		out 0xA1,al

		; Restore the original interrupt vectors
		mov si,oldirq0
		mov di,4*08h
		mov cx,8
		rep movsd
		mov di,4*70h
		mov cx,8
		rep movsd

		xor ax,ax
		mov [SerialIRQPort],ax		; No active interrupt system

.done:
		pop es
		pop ds
		popad
		ret

sirq_cleanup:
		call sirq_cleanup_nowipe
		pushad
		push es
		; Just in case it might contain a password, erase the
		; serial port receive buffer...
		mov ax,aux_seg + (aux.serial >> 4)
		mov es,ax
		xor eax,eax
		mov [cs:SerialHead],eax
		mov cx,serial_buf_size >> 2
		xor di,di
		rep stosd
		pop es
		popad
		ret

		section .text
1	niro	1133	;; -----------------------------------------------------------------------
2			;;
3			;; Copyright 2009 Intel Corporation; author: H. Peter Anvin
4			;;
5			;; This program is free software; you can redistribute it and/or modify
6			;; it under the terms of the GNU General Public License as published by
7			;; the Free Software Foundation, Inc., 53 Temple Place Ste 330,
8			;; Boston MA 02111-1307, USA; either version 2 of the License, or
9			;; (at your option) any later version; incorporated herein by reference.
10			;;
11			;; -----------------------------------------------------------------------
12
13			;;
14			;; serirq.inc
15			;;
16			;; Serial port IRQ code
17			;;
18			;; We don't know what IRQ, if any, we have, so map all of them...
19			;;
20
21			section .text
22			bits 16
23			align 8
24
25			section .bss
26			alignb 8
27
28			%assign n 0
29			%rep 16
30			section .text
31			serstub_irq %+ n :
32			push dword [cs:oldirq %+ n]
33			jmp short irq_common
34
35			section .bss
36			oldirq %+ n resd 1
37			%assign n n+1
38			%endrep
39
40			section .text
41			irq_common:
42			pushf
43			push ax
44			push dx
45			mov dx,[cs:SerialPort]
46			add dx,5 ; DX -> LSR
47			in al,dx
48			test al,1 ; Received data
49			jnz .data
50			.done:
51			pop dx
52			pop ax
53			popf
54			retf ; Chain to next handler
55			.data:
56			push es
57			push di
58			mov ax,aux_seg + (aux.serial >> 4)
59			mov es,ax
60			mov di,[cs:SerialHead]
61			.loop:
62			mov dx,[cs:SerialPort] ; DX -> RDR
63			in al,dx
64			stosb
65			mov ah,[cs:FlowIgnore]
66			add dx,5 ; DX -> LSR
67			in al,dx
68			push ax
69			and al,ah
70			cmp al,ah
71			jne .drop
72			and di,serial_buf_size-1 ; Wrap around if necessary
73			cmp di,[cs:SerialTail] ; Would this cause overflow?
74			je .drop ; If so, just drop the data
75			mov [cs:SerialHead],di
76			.drop:
77			pop ax
78			test al,1 ; More data?
79			jnz .loop
80			.full:
81			pop di
82			pop es
83			jmp .done
84
85			section .data
86			;
87			; SerialIRQPort will generally track SerialPort, but will be 0 when an
88			; IRQ service is not installed.
89			;
90			SerialIRQPort dw 0 ; Serial port w IRQ service
91			SerialHead dw 0 ; Head of serial port rx buffer
92			SerialTail dw 0 ; Tail of serial port rx buffer
93
94			section .bss
95			IRQMask resw 1 ; PIC IRQ mask status
96
97			section .text
98
99			sirq_install:
100			pushad
101
102			call sirq_cleanup
103
104			; Save the old interrupt vectors
105			mov si,4*08h
106			mov di,oldirq0
107			mov cx,8
108			rep movsd
109			mov si,4*70h
110			mov cx,8
111			rep movsd
112
113			; Install new interrupt vectors
114			mov di,4*08h
115			mov cx,8
116			mov eax,serstub_irq0
117			.pic0:
118			stosd
119			add ax,serstub_irq1 - serstub_irq0
120			loop .pic0
121			mov di,4*70h
122			mov cx,8
123			.pic1:
124			stosd
125			add ax,serstub_irq1 - serstub_irq0
126			loop .pic1
127
128			mov bx,[SerialPort]
129			mov [SerialIRQPort],bx
130
131			lea dx,[bx+5] ; DX -> LCR
132			mov al,03h ; Clear DLAB (should already be...)
133			slow_out dx,al
134
135			lea dx,[bx+1] ; DX -> IER
136			mov al,1 ; Enable receive interrupt
137			slow_out dx,al
138
139			;
140			; Enable all ther interupt lines at the PIC. Some BIOSes
141			; only enable the timer interrupts and other interrupts
142			; actively in use by the BIOS.
143			;
144			in al,0xA1 ; Secondary PIC mask register
145			mov ah,al
146			in al,0x21 ; Primary PIC mask register
147			mov [IRQMask],ax
148
149			io_delay
150
151			xor ax,ax ; Remove all interrupt masks
152			out 0x21,al
153			out 0xA1,al
154
155			popad
156			ret
157
158			sirq_cleanup_nowipe:
159			pushad
160			push ds
161			push es
162			xor ax,ax
163			mov ds,ax
164			mov es,ax
165
166			mov bx,[SerialIRQPort]
167			and bx,bx
168			jz .done
169
170			lea dx,[bx+5] ; DX -> LCR
171			mov al,03h ; Clear DLAB (should already be...)
172			slow_out dx,al
173
174			lea dx,[bx+1] ; DX -> IER
175			xor ax,ax
176			slow_out dx,al ; Clear IER
177
178			; Restore PIC masks
179			mov ax,[IRQMask]
180			out 0x21,al
181			mov al,ah
182			out 0xA1,al
183
184			; Restore the original interrupt vectors
185			mov si,oldirq0
186			mov di,4*08h
187			mov cx,8
188			rep movsd
189			mov di,4*70h
190			mov cx,8
191			rep movsd
192
193			xor ax,ax
194			mov [SerialIRQPort],ax ; No active interrupt system
195
196			.done:
197			pop es
198			pop ds
199			popad
200			ret
201
202			sirq_cleanup:
203			call sirq_cleanup_nowipe
204			pushad
205			push es
206			; Just in case it might contain a password, erase the
207			; serial port receive buffer...
208			mov ax,aux_seg + (aux.serial >> 4)
209			mov es,ax
210			xor eax,eax
211			mov [cs:SerialHead],eax
212			mov cx,serial_buf_size >> 2
213			xor di,di
214			rep stosd
215			pop es
216			popad
217			ret
218
219			section .text