X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=bootcensus;a=blobdiff_plain;f=src%2Fboot%2Fboot.s;h=4f0023a025b4c97d55cfda9e04914fe83e1c5f90;hp=7f8ee685a241218d102c11fdd570b2d9b6ab94cf;hb=e253f9a0cad14f636a51f6211308491ab19dfbe5;hpb=06e632cd7cf56db0d187bf1c8ee80172bc56e685

diff --git a/src/boot/boot.s b/src/boot/boot.s
index 7f8ee68..4f0023a 100644
--- a/src/boot/boot.s
+++ b/src/boot/boot.s
@@ -1,5 +1,21 @@
+# pcboot - bootable PC demo/game kernel
+# Copyright (C) 2018-2019  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/>.
+
 	.code16
-	.section .boot,"a"
+	.section .boot,"ax"
 
 	.set stack_top, 0x7be0
 	.set read_retries, 0x7be8
@@ -21,8 +37,6 @@ boot:
 
 	mov %dl, drive_number
 
-	call setup_serial
-
 	call get_drive_chs
 
 	mov $loading_msg, %si
@@ -32,6 +46,7 @@ boot:
 	mov $_boot2_size, %eax
 	call print_num
 
+	mov $_boot2_size, %eax
 	mov %eax, %ebx
 	shr $9, %eax
 	and $0x1ff, %ebx
@@ -48,15 +63,16 @@ boot:
 	call read_sectors
 	jmp boot2_addr
 
-	.set ARG_NSECT, 6
-	.set ARG_SIDX, 4
-
 loading_msg: .asciz "\nLoad "
-driveno_msg: .asciz "Drive: "
+driveno_msg: .asciz "Drv:"
 
+	.global sect_per_track
 sect_per_track: .short 18
+	.global num_cylinders
 num_cylinders: .short 80
+	.global num_heads
 num_heads: .short 2
+	.global heads_mask
 heads_mask: .byte 1
 
 get_drive_chs:
@@ -71,10 +87,10 @@ get_drive_chs:
 
 	mov $8, %ah
 	int $0x13
-	jnc .Lok
+	jnc ok
 	ret
 
-.Lok:	xor %eax, %eax
+ok:	xor %eax, %eax
 	mov %ch, %al
 	mov %cl, %ah
 	rol $2, %ah
@@ -101,6 +117,10 @@ get_drive_chs:
 	call print_num
 	ret
 
+
+	.set ARG_NSECT, 6
+	.set ARG_SIDX, 4
+
 # read_sectors(first, num)
 read_sectors:
 	push %bp
@@ -130,7 +150,7 @@ read_sector:
 
 	movw $3, read_retries
 
-.Lread_try:
+read_try:
 	# calculate the track (sidx / sectors_per_track)
 	mov 4(%bp), %ax
 
@@ -162,22 +182,22 @@ read_sector:
 	mov $0x0201, %ax
 	movb drive_number, %dl
 	int $0x13
-	jnc .Lread_ok
+	jnc read_ok
 
 	# abort after 3 attempts
 	decw read_retries
-	jz .Lread_fail
+	jz read_fail
 
 	# error detected, reset controller and retry
 	xor %ah, %ah
 	int $0x13
-	jmp .Lread_try
+	jmp read_try
 
-.Lread_fail:
+read_fail:
 	mov 4(%bp), %ax
 	jmp abort_read
 
-.Lread_ok:
+read_ok:
 	mov $46, %ax
 	call print_char
 
@@ -193,7 +213,7 @@ read_sector:
 	pop %bp
 	ret
 
-str_read_error: .asciz "rderr: "
+str_read_error: .asciz "rderr:"
 
 abort_read:
 	mov $str_read_error, %si
@@ -210,18 +230,23 @@ print_str:
 
 0:	mov (%si), %al
 	cmp $0, %al
-	jz .Lend
+	jz end
 	call print_char
 	inc %si
 	jmp 0b
 
-.Lend:	popa
+end:	popa
 	ret
 
 	# expects character in al
 print_char:
 	push %es
-	pushw $0xb800
+
+	cmp $10, %ax
+	jnz 0f
+	mov $32, %ax
+
+0:	pushw $0xb800
 	pop %es
 	movw cursor_x, %di
 	shl $1, %di
@@ -230,7 +255,6 @@ print_char:
 	movb $7, %es:1(%di)
 	incw cursor_x
 
-	call ser_putchar
 	pop %es
 	ret
 
@@ -243,14 +267,14 @@ print_num:
 	movw $scratchbuf + scratchbuf_size, %si
 	movb $0, (%si)
 	mov $10, %ebx
-.Lconvloop:
+convloop:
 	xor %edx, %edx
 	div %ebx
 	add $48, %dl
 	dec %si
 	mov %dl, (%si)
 	cmp $0, %eax
-	jnz .Lconvloop
+	jnz convloop
 
 	call print_str
 
@@ -258,78 +282,6 @@ print_num:
 	popa
 	ret
 
-	.set UART_DATA, 0x3f8
-	.set UART_DIVLO, 0x3f8
-	.set UART_DIVHI, 0x3f9
-	.set UART_FIFO, 0x3fa
-	.set UART_LCTL, 0x3fb
-	.set UART_MCTL, 0x3fc
-	.set UART_LSTAT, 0x3fd
-	.set DIV_9600, 115200 / 9600
-	.set LCTL_8N1, 0x03
-	.set LCTL_DLAB, 0x80
-	.set FIFO_ENABLE, 0x01
-	.set FIFO_SEND_CLEAR, 0x04
-	.set FIFO_RECV_CLEAR, 0x02
-	.set MCTL_DTR, 0x01
-	.set MCTL_RTS, 0x02
-	.set MCTL_OUT2, 0x08
-	.set LST_TREG_EMPTY, 0x20
-
-setup_serial:
-	# set clock divisor
-	mov $LCTL_DLAB, %al
-	mov $UART_LCTL, %dx
-	out %al, %dx
-	mov $DIV_9600, %ax
-	mov $UART_DIVLO, %dx
-	out %al, %dx
-	shr $8, %ax
-	mov $UART_DIVHI, %dx
-	out %al, %dx
-	# set format 8n1
-	mov $LCTL_8N1, %al
-	mov $UART_LCTL, %dx
-	out %al, %dx
-	# clear and enable fifo
-	mov $FIFO_ENABLE, %al
-	or $FIFO_SEND_CLEAR, %al
-	or $FIFO_RECV_CLEAR, %al
-	mov $UART_FIFO, %dx
-	out %al, %dx
-	# assert RTS and DTR
-	mov $MCTL_DTR, %al
-	or $MCTL_RTS, %al
-	or $MCTL_OUT2, %al
-	mov $UART_MCTL, %dx
-	out %al, %dx
-	ret
-
-	# expects a character in al
-	.global ser_putchar
-ser_putchar:
-	push %dx
-
-	cmp $10, %al
-	jnz 0f
-	push %ax
-	mov $13, %al
-	call ser_putchar
-	pop %ax
-
-0:	mov %al, %ah
-	# wait until the transmit register is empty
-	mov $UART_LSTAT, %dx
-.Lwait:	in %dx, %al
-	and $LST_TREG_EMPTY, %al
-	jz .Lwait
-	mov $UART_DATA, %dx
-	mov %ah, %al
-	out %al, %dx
-
-	pop %dx
-	ret
-	
 	.org 510
 	.byte 0x55
 	.byte 0xaa