cleanup and getchs

diff --git a/src/boot/boot.s b/src/boot/boot.s
index b9e1a76..2202800 100644 (file)
--- a/src/boot/boot.s
+++ b/src/boot/boot.s
@@ -1,7 +1,8 @@
        .code16
        .section .boot,"a"
 
-       .set scratchbuf, 0x7b00
+       .set scratchbuf, 0x7bf0
+       .set scratchbuf_size, 16
 
 boot:
        cli
@@ -9,7 +10,7 @@ boot:
        # move stack to just below the code
        xor %ax, %ax
        mov %ax, %ss
-       mov $0x7b00, %sp
+       mov $0x7bf0, %sp
        # use the code segment for data access
        mov %cs, %ax
        mov %ax, %ds
@@ -19,8 +20,15 @@ boot:
 
        call setup_serial
 
+       mov $loading_msg, %si
+       call print_str
+
        # load the second stage boot loader and jump to it
        mov $_boot2_size, %eax
+       call print_num
+       mov $loading_msg2, %si
+       call print_str
+
        mov %eax, %ebx
        shr $9, %eax
        and $0x1ff, %ebx
@@ -42,6 +50,37 @@ boot:
        .set ARG_NSECT, 6
        .set ARG_SIDX, 4
 
+loading_msg: .asciz "Loading "
+loading_msg2: .asciz " bytes\n"
+
+sect_per_track: .short 18
+num_cylinders: .short 80
+num_heads: .short 2
+heads_mask: .byte 1
+
+get_drive_chs:
+       movb drive_number, %dl
+       mov $8, %ah
+       int $0x13
+       jnc .Lok
+       ret
+
+.Lok:  mov %ch, %al
+       mov %cl, %ah
+       rol $2, %ah
+       and $0x3ff, %ax
+       mov %ax, num_cylinders
+
+       mov %cx, sect_per_track
+       andw $0x3f, sect_per_track
+
+       shr $8, %dx
+       mov %dx, num_heads
+       dec %dl
+       mov %dl, heads_mask
+
+       ret
+
 # read_sectors(first, num)
 read_sectors:
        push %bp
@@ -63,7 +102,6 @@ read_sectors:
        ret
 
        .set VAR_ATTEMPTS, -2
-#str_rdsec_msg: .asciz "rdsec: "
 
 # read_sector(sidx)
 read_sector:
@@ -78,23 +116,28 @@ read_sector:
 .Lread_try:
        # calculate the track (sidx / sectors_per_track)
        mov 4(%bp), %ax
-#      mov $str_rdsec_msg, %si
-#      call print_str_num16
 
        xor %dx, %dx
-       mov $SECT_PER_TRACK, %cx
+       mov sect_per_track, %cx
        div %cx
        mov %ax, %cx
-       # save the remainder in ax
-       mov %dx, %ax
+       # save the remainder
+       push %dx
        # head in dh
        mov %cl, %dh
-       and $1, %dh
-       # cylinder (track/2) in ch [0-7] and cl[6,7]<-[8,9]
-       rol $7, %cx
+       and heads_mask, %dh
+       # cylinder (track/heads) in ch [0-7] and cl[6,7]<-[8,9]
+       push %dx
+       xor %dx, %dx
+       movw num_heads, %cx
+       div %cx
+       pop %dx
+       mov %ax, %cx
+       rol $8, %cx
        ror $2, %cl
        and $0xc0, %cl
-       # sector num cl[0-5] is sidx % sectors_per_track (saved in ax)
+       # sector num cl[0-5] is sidx % sectors_per_track + 1
+       pop %ax
        inc %al
        or %al, %cl
 
@@ -118,10 +161,8 @@ read_sector:
        jmp abort_read
 
 .Lread_ok:
-       # DBG print first dword
-#      mov $str_read_error + 4, %si
-#      mov %es:(%bx), %eax
-#      call print_str_num
+       mov $46, %ax
+       call print_char
 
        # increment es:bx accordingly (advance es if bx overflows)
        add $512, %bx
@@ -136,23 +177,19 @@ read_sector:
        pop %bp
        ret
 
-str_read_error: .asciz "err read sect: "
+str_read_error: .asciz "read error, sector: "
 
 abort_read:
        mov $str_read_error, %si
        call print_str_num16
        hlt
 
-cursor_x: .byte 0
-
        # prints a string (ds:si) followed by a number (eax)
 print_str_num:
        push %eax
        call print_str
        pop %eax
        call print_num
-       mov $13, %al
-       call ser_putchar
        mov $10, %al
        call ser_putchar
        ret
@@ -166,74 +203,58 @@ print_str_num16:
 
        # expects string pointer in ds:si
 print_str:
-       push %es
        pusha
 
+0:     mov (%si), %al
+       cmp $0, %al
+       jz .Lend
+       call print_char
+       inc %si
+       jmp 0b
+
+.Lend: popa
+       ret
+
+       # expects character in al
+print_char:
+       push %es
        pushw $0xb800
        pop %es
-       xor %di, %di
-       movb $0, cursor_x
-
-       push %si
+       movw cursor_x, %di
+       shl $1, %di
 
-0:     mov (%si), %al
        mov %al, %es:(%di)
        movb $7, %es:1(%di)
-       inc %si
-       add $2, %di
-       incb cursor_x
-       cmp $0, %al
-       jnz 0b
-
-       pop %si
-       call ser_putstr
+       incw cursor_x
 
-       popa
+       call ser_putchar
        pop %es
        ret
 
+cursor_x: .short 0
+
        # expects number in eax
        .global print_num
 print_num:
        # save registers
-       push %es
        pusha
 
-       xor %cx, %cx
-       movw $scratchbuf, %si
+       movw $scratchbuf + scratchbuf_size, %si
+       movb $0, (%si)
        mov $10, %ebx
-
-0:     xor %edx, %edx
+.Lconvloop:
+       xor %edx, %edx
        div %ebx
        add $48, %dl
+       dec %si
        mov %dl, (%si)
-       inc %si
-       inc %cx
        cmp $0, %eax
-       jnz 0b
+       jnz .Lconvloop
 
-       # print the backwards string
-       pushw $0xb800
-       pop %es
-       movb cursor_x, %al
-       xor %ah, %ah
-       shl $1, %ax
-       mov %ax, %di
-
-0:     dec %si
-       mov (%si), %al
-       movb %al, %es:(%di)
-       call ser_putchar
-       inc %di
-       mov $7, %al
-       movb %al, %es:(%di)
-       inc %di
-       dec %cx
-       jnz 0b
+       call print_str
 
        # restore regs
        popa
-       pop %es
        ret
 
        .set UART_DATA, 0x3f8
@@ -288,28 +309,25 @@ setup_serial:
 ser_putchar:
        push %dx
 
-       mov %al, %ah
+       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
-0:     in %dx, %al
+.Lwait:        in %dx, %al
        and $LST_TREG_EMPTY, %al
-       jz 0b
+       jz .Lwait
        mov $UART_DATA, %dx
        mov %ah, %al
        out %al, %dx
 
        pop %dx
        ret
-
-       # expects a string in ds:si
-ser_putstr:
-       mov (%si), %al
-       cmp $0, %al
-       jz 0f
-       call ser_putchar
-       inc %si
-       jmp ser_putstr
-0:     ret
        
 
 drive_number: .byte 0

diff --git a/src/boot/boot2.s b/src/boot/boot2.s
index 86ee611..838af46 100644 (file)
--- a/src/boot/boot2.s
+++ b/src/boot/boot2.s
@@ -2,7 +2,6 @@
        .code16
        .section .boot2,"a"
 
-       .extern print_num
        .extern ser_putchar
 
        mov $0x13, %ax
@@ -16,8 +15,8 @@
        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 +29,8 @@
        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 +40,8 @@
        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 +51,10 @@
        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
@@ -79,6 +76,46 @@
        cli
        hlt
 
+       # 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"