MS-DOS-kernel/kernel/irqstack.asm at master · Programuserbash/MS-DOS-kernel · GitHub

History

246 lines (200 loc) · 7.32 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

; File:

; irqstack.asm

; Description:

; Assembly support routines for hardware stack support

;

; Svante Frey

;

; This file is part of DOS-C.

;

; DOS-C 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; either version

; 2, or (at your option) any later version.

;

; DOS-C is distributed in the hope that it will be useful, but

; WITHOUT ANY WARRANTY; without even the implied warranty of

; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See

; the GNU General Public License for more details.

;

; You should have received a copy of the GNU General Public

; License along with DOS-C; see the file COPYING. If not,

; write to the Free Software Foundation, 675 Mass Ave,

; Cambridge, MA 02139, USA.

;

; $Id: irqstack.asm 1567 2011-04-09 02:03:20Z bartoldeman $

;

; Code for stack switching during hardware interrupts.

; Format of interrupt sharing protocol interrupt handler entry point:

; Offset Size Description (Table 02568)

; 00h 2 BYTEs short jump to actual start of interrupt handler, immediately

; following this data block (EBh 10h)

; 02h DWORD address of next handler in chain

; 06h WORD signature 424Bh

; 08h BYTE EOI flag

; 00h software interrupt or secondary hardware interrupt handler

; 80h primary hardware interrupt handler (will issue EOI to

; interrupt controller)

; 09h 2 BYTEs short jump to hardware reset routine

; must point at a valid FAR procedure (may be just RETF)

; 0Bh 7 BYTEs reserved (0) by IBM for future expansion

; Ralf Brown documents that irq 2, 3, 4, 5, 6, 10, 11, 12, 14, 15 use the above

; protocol..

; MS (http://support.microsoft.com/kb/84300/)

; documents that STACKS= implements stacks for interrupt vectors

; 02H, 08-0EH, 70H, and 72-77H.

; that means that we need to redirect NMI (INT 2), irq 0, 1, 8, 13 without sharing

; irq 9 (==irq2) and irq 7 (printer) are not handled at all

%include "segs.inc"

segment _IRQTEXT

stack_size dw 0

stack_top dw 0

stack_offs dw 0

stack_seg dw 0

%macro irq 0

call general_irq_service

dd 0

%endmacro

%macro irqshare 1

jmp short %%1

dd 0

dw 424bh

db 0

jmp short retf%1

times 7 db 0

%%1: call general_irq_service_share

%endmacro

nmi: irq

irq_0: irq

irq_1: irq

irq_08: irq

irq_0d: irq

retf1: retf

irq_2: irqshare 1

irq_3: irqshare 1

irq_4: irqshare 1

irq_5: irqshare 1

irq_6: irqshare 1

irq_0a: irqshare 2

irq_0b: irqshare 2

irq_0c: irqshare 2

irq_0e: irqshare 2

irq_0f: irqshare 2

retf2: retf

; align to 100h to align _LOWTEXT for interrupt vectors

; in kernel.asm

times (100h - ($ - stack_size)) db 0

segment _IO_TEXT

general_irq_service:

push bx

mov bx, sp

mov bx, [ss:bx+2] ; return address->old ivec

jmp short common_irq

general_irq_service_share:

push bx

mov bx, sp

mov bx, [ss:bx+2] ; return address->old ivec

sub bx, byte irq_3 - irq_2 - 2

common_irq:

push dx

push ax

push ds

mov ax, cs

mov ds, ax

mov ax, [stack_top]

cmp ax, [stack_offs]

jbe dont_switch

mov dx, ss

mov ax, sp

mov ss, [stack_seg]

mov sp, [stack_top]

push dx ; save old SS:SP on new stack

push ax

mov ax, [stack_size]

sub [stack_top], ax

pushf

call far word [bx]

cli

add [stack_top], ax

pop ax ; get stored SS:SP

pop dx

mov ss, dx ; switch back to old stack

mov sp, ax

return: pop ds ; restore registers and return

pop ax

pop dx

pop bx

add sp, byte 2

iret

dont_switch: pushf

call far word [bx]

jmp short return

segment INIT_TEXT

global _init_stacks

; VOID init_stacks(VOID FAR *stack_base, COUNT nStacks, WORD stackSize);

int_numbers: db 2,8,9,70h,75h

int_numbers_share: db 0ah,0bh,0ch,0dh,0eh,72h,73h,74h,76h,77h

_init_stacks:

push bp

mov bp, sp

push ds

push di

push si

mov ax,LGROUP

mov ds,ax

mov es,ax

mov bx, [bp+4]

mov dx, [bp+6]

mov ax, [bp+8]

mov cx, [bp+0ah]

mov [stack_size], cx

mov [stack_offs], bx

mov [stack_seg], dx

mul cx

add ax, bx

; stack_top = stack_size * nStacks + stack_seg:stack_offs

mov [stack_top], ax

xor ax, ax

mov ds, ax

mov di, nmi + 3

mov dx, nmi

mov bx, int_numbers

mov cx, int_numbers_share - int_numbers

mov bp, irq_1 - irq_0

call set_vect

inc dx ; skip over retf (not di: go from nmi+3 to irq_2+2)

mov cx, _init_stacks - int_numbers_share

mov bp, irq_3 - irq_2

call set_vect

pop si

pop di

pop ds

pop bp

ret

; set interrupt vectors:

; in: es=LGROUP, ds=0

; bx: pointer to int_numbers bytes in cs

; cx: number of vectors to set

; dx: pointer to es:nmi and so on (new interrupt vectors)

; di: pointer to es:nmi+3 and so on (pointer to place of old interrupt vectors)

; bp: difference in offset between irq structures

; out: bx, si, di updated, cx=0, ax destroyed

set_vect:

mov al, [cs:bx] ; get next int vector offset

inc bx

cbw

mov si, ax

shl si, 1

shl si, 1 ; now ds:si -> int vector, es:di -> nmi+3, etc

movsw ; save old vector

movsw

cli

mov [si-4], dx ; set new vector

mov [si-2], es

sti

add dx, bp

lea di, [di+bp-4] ; update di, compensating for movsw

loop set_vect

ret

MS-DOS-kernel/kernel/irqstack.asm at master · Programuserbash/MS-DOS-kernel · GitHub

Expand file tree

Breadcrumbs

irqstack.asm

Latest commit

History

Breadcrumbs

irqstack.asm

File metadata and controls