X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=src%2Fboot%2Fboot2.s;h=ec6f4074f27f6b4bcb7c8e3b78839c552f832efa;hb=a6dab855a9f35a8d19016f985d228f6a7b2c5335;hp=86ee611d309a754d3b773eb05e1f68e0d79b68c4;hpb=e552b31989dbb36f780428332be1b4958d26a37b;p=bootcensus

diff --git a/src/boot/boot2.s b/src/boot/boot2.s
index 86ee611..ec6f407 100644
--- a/src/boot/boot2.s
+++ b/src/boot/boot2.s
@@ -1,13 +1,31 @@
+# pcboot - bootable PC demo/game kernel
+# Copyright (C) 2018  John Tsiombikas <nuclear@member.fsf.org>
+# 
+# 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, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
+
 # this is the second-stage boot loader
 	.code16
 	.section .boot2,"a"
 
-	.extern print_num
 	.extern ser_putchar
 
 	mov $0x13, %ax
 	int $0x10
 
+	movb $10, %al
+	call ser_putchar
+
 	# copy palette
 	mov $logo_pal, %si
 	xor %cl, %cl
@@ -16,8 +34,8 @@
 	mov $0x3c8, %dx
 	movb %cl, %al
 	outb %al, %dx
-	#DBG
-	call print_num
+	#### DBG
+	call ser_print_num
 	mov $58, %al
 	call ser_putchar
 	mov $32, %al
@@ -30,8 +48,8 @@
 	inc %si
 	shr $2, %al
 	outb %al, %dx
-	#DBG
-	call print_num
+	#### DBG
+	call ser_print_num
 	mov $32, %al
 	call ser_putchar
 	xor %eax, %eax
@@ -41,8 +59,8 @@
 	inc %si
 	shr $2, %al
 	outb %al, %dx
-	#DBG
-	call print_num
+	#### DBG
+	call ser_print_num
 	mov $32, %al
 	call ser_putchar
 	xor %eax, %eax
@@ -52,12 +70,10 @@
 	inc %si
 	shr $2, %al
 	outb %al, %dx
-	#DBG
-	call print_num
+	#### DBG
+	call ser_print_num
 	mov $32, %al
 	call ser_putchar
-	mov $13, %al
-	call ser_putchar
 	mov $10, %al
 	call ser_putchar
 	xor %eax, %eax
@@ -68,20 +84,397 @@
 	# copy pixels
 	pushw $0xa000
 	pop %es
-	xor %di, %di
 	mov $logo_pix, %eax
 	shr $4, %eax
-	mov %ax, %ds
-	xor %si, %si
-	mov $16000, %ecx
-	rep movsl
+	#mov %ax, %ds
+	mov %ax, %gs
+	#mov $16000, %ecx
+	#rep movsl
+
+	mov $sintab, %eax
+	shr $4, %eax
+	mov %ax, %fs
+
+.Lframeloop:
+	xor %di, %di
+
+	movw $0, yval
+.Lyloop:
+	movw $0, xval
+.Lxloop:
+	# calc src scanline address -> bx
+	mov yval, %bx
+	shl $2, %bx
+	add frameno, %bx
+	xor %bh, %bh
+	mov %fs:(%bx), %cl
+	xor %ch, %ch
+	shr $5, %cx
+
+	mov yval, %ax
+	add %cx, %ax
+	# bounds check
+	cmp $200, %ax
+	jl 0f
+	mov $199, %ax
+
+0:	mov %ax, %bx
+	shl $8, %ax
+	shl $6, %bx
+	add %ax, %bx
+
+	# calc src x offset -> si
+	mov xval, %ax
+	shl $2, %ax
+	add frameno, %ax
+	xor %ah, %ah
+	mov %ax, %si
+	mov %fs:(%si), %cl
+	xor %ch, %ch
+	shr $5, %cx
+
+	mov xval, %ax
+	add %cx, %ax
+	# bounds check
+	cmp $320, %ax
+	jl 0f
+	mov $319, %ax
+
+0:	mov %ax, %si
+
+	mov %gs:(%bx, %si), %al
+
+	mov %al, %es:(%di)
+	inc %di
+
+	incw xval
+	cmpw $320, xval
+	jnz .Lxloop
+
+	incw yval
+	cmpw $200, yval
+	jnz .Lyloop
+
+	incw frameno
+
+	# wait vsync
+	mov $0x3da, %dx
+0:	in %dx, %al
+	and $8, %al
+	jnz 0b
+0:	in %dx, %al
+	and $8, %al
+	jz 0b
+	jmp .Lframeloop
 
 	cli
 	hlt
 
+xval: .word 0
+yval: .word 0
+frameno: .word 0
+
+	# expects string pointer in ds:si
+ser_print_str:
+	pusha
+
+0:	mov (%si), %al
+	cmp $0, %al
+	jz .Lend
+	call ser_putchar
+	inc %si
+	jmp 0b
+
+.Lend:	popa
+	ret
+
+
+	# expects number in eax
+ser_print_num:
+	# save registers
+	pusha
+
+	movw $numbuf + 16, %si
+	movb $0, (%si)
+	mov $10, %ebx
+.Lconvloop:
+	xor %edx, %edx
+	div %ebx
+	add $48, %dl
+	dec %si
+	mov %dl, (%si)
+	cmp $0, %eax
+	jnz .Lconvloop
+
+	call ser_print_str
+
+	# restore regs
+	popa
+	ret
+
+numbuf: .space 16
+
 logo_pal:
 	.incbin "logo.pal"
 
 	.align 16
 logo_pix:
 	.incbin "logo.raw"
+
+sintab:
+	.byte 127
+	.byte 130
+	.byte 133
+	.byte 136
+	.byte 139
+	.byte 143
+	.byte 146
+	.byte 149
+	.byte 152
+	.byte 155
+	.byte 158
+	.byte 161
+	.byte 164
+	.byte 167
+	.byte 170
+	.byte 173
+	.byte 176
+	.byte 179
+	.byte 182
+	.byte 184
+	.byte 187
+	.byte 190
+	.byte 193
+	.byte 195
+	.byte 198
+	.byte 200
+	.byte 203
+	.byte 205
+	.byte 208
+	.byte 210
+	.byte 213
+	.byte 215
+	.byte 217
+	.byte 219
+	.byte 221
+	.byte 224
+	.byte 226
+	.byte 228
+	.byte 229
+	.byte 231
+	.byte 233
+	.byte 235
+	.byte 236
+	.byte 238
+	.byte 239
+	.byte 241
+	.byte 242
+	.byte 244
+	.byte 245
+	.byte 246
+	.byte 247
+	.byte 248
+	.byte 249
+	.byte 250
+	.byte 251
+	.byte 251
+	.byte 252
+	.byte 253
+	.byte 253
+	.byte 254
+	.byte 254
+	.byte 254
+	.byte 254
+	.byte 254
+	.byte 255
+	.byte 254
+	.byte 254
+	.byte 254
+	.byte 254
+	.byte 254
+	.byte 253
+	.byte 253
+	.byte 252
+	.byte 251
+	.byte 251
+	.byte 250
+	.byte 249
+	.byte 248
+	.byte 247
+	.byte 246
+	.byte 245
+	.byte 244
+	.byte 242
+	.byte 241
+	.byte 239
+	.byte 238
+	.byte 236
+	.byte 235
+	.byte 233
+	.byte 231
+	.byte 229
+	.byte 228
+	.byte 226
+	.byte 224
+	.byte 221
+	.byte 219
+	.byte 217
+	.byte 215
+	.byte 213
+	.byte 210
+	.byte 208
+	.byte 205
+	.byte 203
+	.byte 200
+	.byte 198
+	.byte 195
+	.byte 193
+	.byte 190
+	.byte 187
+	.byte 184
+	.byte 182
+	.byte 179
+	.byte 176
+	.byte 173
+	.byte 170
+	.byte 167
+	.byte 164
+	.byte 161
+	.byte 158
+	.byte 155
+	.byte 152
+	.byte 149
+	.byte 146
+	.byte 143
+	.byte 139
+	.byte 136
+	.byte 133
+	.byte 130
+	.byte 127
+	.byte 124
+	.byte 121
+	.byte 118
+	.byte 115
+	.byte 111
+	.byte 108
+	.byte 105
+	.byte 102
+	.byte 99
+	.byte 96
+	.byte 93
+	.byte 90
+	.byte 87
+	.byte 84
+	.byte 81
+	.byte 78
+	.byte 75
+	.byte 72
+	.byte 70
+	.byte 67
+	.byte 64
+	.byte 61
+	.byte 59
+	.byte 56
+	.byte 54
+	.byte 51
+	.byte 49
+	.byte 46
+	.byte 44
+	.byte 41
+	.byte 39
+	.byte 37
+	.byte 35
+	.byte 33
+	.byte 30
+	.byte 28
+	.byte 26
+	.byte 25
+	.byte 23
+	.byte 21
+	.byte 19
+	.byte 18
+	.byte 16
+	.byte 15
+	.byte 13
+	.byte 12
+	.byte 10
+	.byte 9
+	.byte 8
+	.byte 7
+	.byte 6
+	.byte 5
+	.byte 4
+	.byte 3
+	.byte 3
+	.byte 2
+	.byte 1
+	.byte 1
+	.byte 0
+	.byte 0
+	.byte 0
+	.byte 0
+	.byte 0
+	.byte 0
+	.byte 0
+	.byte 0
+	.byte 0
+	.byte 0
+	.byte 0
+	.byte 1
+	.byte 1
+	.byte 2
+	.byte 3
+	.byte 3
+	.byte 4
+	.byte 5
+	.byte 6
+	.byte 7
+	.byte 8
+	.byte 9
+	.byte 10
+	.byte 12
+	.byte 13
+	.byte 15
+	.byte 16
+	.byte 18
+	.byte 19
+	.byte 21
+	.byte 23
+	.byte 25
+	.byte 26
+	.byte 28
+	.byte 30
+	.byte 33
+	.byte 35
+	.byte 37
+	.byte 39
+	.byte 41
+	.byte 44
+	.byte 46
+	.byte 49
+	.byte 51
+	.byte 54
+	.byte 56
+	.byte 59
+	.byte 61
+	.byte 64
+	.byte 67
+	.byte 70
+	.byte 72
+	.byte 75
+	.byte 78
+	.byte 81
+	.byte 84
+	.byte 87
+	.byte 90
+	.byte 93
+	.byte 96
+	.byte 99
+	.byte 102
+	.byte 105
+	.byte 108
+	.byte 111
+	.byte 115
+	.byte 118
+	.byte 121
+	.byte 124