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comparison packages/hal/i386/pc/current/include/platform.inc @ 134:d2f49caf9e38 ecos-sw-2000-11-03

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Merge from eCos master repository on 2000-11-03-09:00:49-GMT
author jlarmour
date Fri, 03 Nov 2000 21:17:40 +0000
parents 6ed91473a1cd
children ac086aa3217e
comparison
equal deleted inserted replaced
133:98d71f4d8243 134:d2f49caf9e38
63 63
64 .extern _end 64 .extern _end
65 65
66 sectorsPerTrack = 18 66 sectorsPerTrack = 18
67 bytesPerSector = 512 67 bytesPerSector = 512
68 bytesPerTrack = sectorsPerTrack * bytesPerSector 68 esPerSector = 32 /* = 512/16 */
69 dptLength = 3 /* words. */
70 69
71 cld /* always count up. */ 70 cld /* always count up. */
72 71
73 /* Configure a stack that we can use. */ 72 /* Configure a stack that we can use. */
74 73
76 movw %ax, %sp 75 movw %ax, %sp
77 shr $4, %eax 76 shr $4, %eax
78 andl $0xF000, %eax 77 andl $0xF000, %eax
79 movw %ax, %ss 78 movw %ax, %ss
80 79
81 /* Ask the BIOS for info about the amount of RAM available. We push these 80 /* Ask the BIOS for info about the amount of RAM available. We push
82 onto the stack for later use. 81 * these onto the stack for later use.
83 */ 82 */
84 83
85 xorl %eax, %eax 84 xorl %eax, %eax
86 movb $0x88, %ah /* Get the amount of extended memory. */ 85 movb $0x88, %ah /* Get the amount of extended memory. */
87 int $0x15 86 int $0x15
88 shl $10, %eax 87 shl $10, %eax
91 xorl %eax, %eax 90 xorl %eax, %eax
92 int $0x12 /* Get the amount of standard memory. */ 91 int $0x12 /* Get the amount of standard memory. */
93 shl $10, %eax 92 shl $10, %eax
94 pushl %eax 93 pushl %eax
95 94
96 95 /* reset floppy */
97 /* Read the rest of the image to _start. This code works by reading a track 96 movb $0,%ah
98 at a time... 97 movb $0,%dl
98 int $0x13
99 jc _error
100
101 /* Read the rest of the image to _start. This code works by reading
102 only one sector at a time to avoid "buffer cross 64k boundary" fatal
103 problem... This is slow but should work in almost all situations.
104 _start should be aligned on a 512 bytes boundary to be sure.
99 */ 105 */
100 106
101 movl $_edata, %eax 107 /* destination pointer es:bx */
102 movl $_start, %ebx /* Our destination address. */ 108 /* With correct alignement, bx should be 0 and es should be a multiple
103 subl %ebx, %eax /* Number of bytes in the image. */ 109 * of 32. If not it may cause the "buffer cross 64k boundary" problem
104 movl $1, %ecx /* Track/sector to read from (starts at 1). */ 110 * (cf above)
105 111 */
106 0: 112 movl $_start,%eax
107 cmpl $0, %eax 113 movw %ax,%bx
108 jle 1f 114 andw $0xF,%bx
109 115 shrl $4,%eax
110 pushl %eax /* Save the number of bytes we want. */
111 pushl %ebx /* Save our current address. */
112 pushl %ecx /* Save our disk location. */
113
114 /* Read in a track with head 0. */
115
116 movl %ebx, %eax /* Put our address into ES:BX. */
117 shr $4, %eax
118 movw %ax, %es 116 movw %ax, %es
119 andl $0xF, %ebx 117
120 movw $0, %dx /* Disk 0, head 0 */ 118 /* initials head/track/sector */
121 movb $0x02, %ah 119 movw $0,%dx
122 movb $sectorsPerTrack, %al /* Read the entire track. */ 120 movw $1,%cx
121
122 xorl %edi,%edi
123 jmp _loadsector
124
125 _nextsector:
126 addw $esPerSector, %di /* advance buffer pointer */
127 shll $4,%edi
128 cmpl $_edata,%edi
129 jg _endload /* next sector ? */
130 shrl $4,%edi
131 movw %di,%es
132 incb %cl
133 cmpb $sectorsPerTrack, %cl
134 jbe _loadsector /* next head ?*/
123 movb $1, %cl 135 movb $1, %cl
124 int $0x13 /* CX points to our track/sector. */ 136 incb %dh
137 cmpb $1, %dh
138 je _loadsector /* next track ? */
139 movb $0, %dh
140 incb %ch
141
142 _loadsector:
143
144 pushw %es
145 movw $0x0201, %ax
146 int $0x13
147 popw %di
148 jc _error
149
150 movw $(0x0E*256+'.'), %ax /* print a dot */
151 int $0x10
125 152
126 /* So go ahead and resume execution at the real starting address. This 153 /* So go ahead and resume execution at the real starting address. This
127 only serves to move us quickly to the real starting location; and has 154 only serves to move us quickly to the real starting location; and has
128 no effect after reading additional tracks. If we didn't jump after 155 no effect after reading additional tracks. If we didn't jump after
129 reading the first track, then we limit ourselves to reading images of 156 reading the first track, then we limit ourselves to reading images of
130 30k bytes max before overwriting ourselves at 0x7C00. 157 30k bytes max before overwriting ourselves at 0x7C00.
131 */ 158 */
132 159
133 ljmp $0, $2f 160 ljmp $0,$_nextsector
161
162 _error: /* halt on error */
163 cli
134 hlt 164 hlt
135 165 jmp _start
136 .align 4
137 2:
138
139 popl %ecx
140 popl %ebx
141 popl %eax
142
143 /* Add our length to the address. */
144 addl $bytesPerTrack, %ebx
145 subl $bytesPerTrack, %eax
146
147 /* Maybe read in a track with head 1. */
148 cmpl $0, %eax
149 jle 1f
150
151 pushl %eax /* Save the number of bytes we want. */
152 pushl %ebx /* Save our current address. */
153 pushl %ecx
154
155 movl %ebx, %eax /* Put our address into ES:BX. */
156 shr $4, %eax
157 movw %ax, %es
158 andl $0xF, %ebx
159 movw $0x0100, %dx /* Disk 0, head 1 */
160 movb $0x02, %ah
161 movb $sectorsPerTrack, %al /* Read the entire track. */
162 movb $1, %cl
163 int $0x13 /* CX points to our track/sector. */
164
165 popl %ecx
166 popl %ebx
167 popl %eax
168
169 /* Add our length to the address. */
170 addl $bytesPerTrack, %ebx
171 subl $bytesPerTrack, %eax
172
173 /* Move to the next track. */
174 addb $0x1, %ch
175
176 jmp 0b
177
178 /* Write the 0x55/0xAA signature at the end of the first 166 /* Write the 0x55/0xAA signature at the end of the first
179 block. Without this signature the BIOS won't consider this 167 block. Without this signature the BIOS won't consider this
180 block to be bootable. 168 block to be bootable.
181 */ 169 */
182 170
183 . = _start + 510 171 . = _start + 510
184 .byte 0x55 172 .byte 0x55
185 .byte 0xAA 173 .byte 0xAA
186 174
187 175 _endload:
188 1: 176 1:
189 177
190 /* Lets be nice and wait for the diskette drive motor to go off before continuing. */ 178 /* Lets be nice and wait for the diskette drive motor to go off
179 * before continuing. */
191 180
192 movw $0x40, %ax 181 movw $0x40, %ax
193 movw %ax, %es 182 movw %ax, %es
194 movl $0x40, %ebx 183 movl $0x40, %ebx
195 2: es 184 2: es
248 .byte 0x00 237 .byte 0x00
249 .byte 0x93 238 .byte 0x93
250 .byte 0xCF 239 .byte 0xCF
251 .byte 0x00 240 .byte 0x00
252 241
253 /* Selector 0x18 == shorter code: faults any code access 0xF0000000-0xFFFFFFFF. */ 242 /* Selector 0x18 == shorter code: faults any code
243 * access 0xF0000000-0xFFFFFFFF.
244 */
254 .word 0xFFFF 245 .word 0xFFFF
255 .word 0x0000 246 .word 0x0000
256 .byte 0x00 247 .byte 0x00
257 .byte 0x9B 248 .byte 0x9B
258 .byte 0xC7 249 .byte 0xC7
290 /* Reset the flags register. */ 281 /* Reset the flags register. */
291 pushl $0 282 pushl $0
292 popfl 283 popfl
293 284
294 /* Save the standard and extended memory lengths into some static variables... 285 /* Save the standard and extended memory lengths into some static variables...
295 I'm predicting that someone is going to break our way of passing a pointer 286 I'm predicting that someone is going to break our way of passing a
296 to this structure... may as well avoid that problem now. 287 pointer to this structure... may as well avoid that problem now.
297 */ 288 */
298 .data 289 .data
299 .align 4 290 .align 4
300 .globl pc_standard_memory_size 291 .globl pc_standard_memory_size
301 pc_standard_memory_size: 292 pc_standard_memory_size:
310 movl %ebx, pc_extended_memory_size 301 movl %ebx, pc_extended_memory_size
311 302
312 /* _pc_entry() takes a pointer to our startup array (which only has standard 303 /* _pc_entry() takes a pointer to our startup array (which only has standard
313 and extended memory sizes in it, on the stack). 304 and extended memory sizes in it, on the stack).
314 */ 305 */
315 movl %esp, %ebx /* They are the last parameters on the stack. */ 306 movl %esp, %ebx /* They are the last parameters on the stack. */
316 pushl %ebx 307 pushl %ebx
317 308
318 #endif /* CYG_HAL_STARTUP_FLOPPY */ 309 #endif /* CYG_HAL_STARTUP_FLOPPY */
319 310
320 #ifdef CYG_HAL_STARTUP_RAM 311 #ifdef CYG_HAL_STARTUP_RAM
321 312
322 /* In this case, the sizes of memory are pointed to by a pointer in IRQ 313 /* In this case, the sizes of memory are pointed to by a pointer in IRQ
323 vector 15. 314 vector 15.
324 */ 315 */
325 316
326 /* Save the standard and extended memory lengths into some static variables... 317 /* Save the standard and extended memory lengths into some static
327 */ 318 * variables...
319 */
328 .data 320 .data
329 .align 4 321 .align 4
330 .globl pc_standard_memory_size 322 .globl pc_standard_memory_size
331 pc_standard_memory_size: 323 pc_standard_memory_size:
332 .long 0 324 .long 0