Fixed dobule-faults: the BIOS 13h calls enabled interrupts behind my back

Protected mode setup works.

diff --git a/src/boot/boot.s b/src/boot/boot.s
index 554f5a2..f17766b 100644 (file)
--- a/src/boot/boot.s
+++ b/src/boot/boot.s
@@ -88,10 +88,10 @@ 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
@@ -147,7 +147,7 @@ read_sector:
 
        movw $3, read_retries
 
-.Lread_try:
+read_try:
        # calculate the track (sidx / sectors_per_track)
        mov 4(%bp), %ax
 
@@ -179,22 +179,22 @@ 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
 
@@ -227,12 +227,12 @@ 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
@@ -267,14 +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
 
@@ -335,9 +335,9 @@ ser_putchar:
 0:     mov %al, %ah
        # wait until the transmit register is empty
        mov $UART_LSTAT, %dx
-.Lwait:        in %dx, %al
+wait:  in %dx, %al
        and $LST_TREG_EMPTY, %al
-       jz .Lwait
+       jz wait
        mov $UART_DATA, %dx
        mov %ah, %al
        out %al, %dx

diff --git a/src/boot/boot2.s b/src/boot/boot2.s
index 0f2bbf8..2d4298f 100644 (file)
--- a/src/boot/boot2.s
+++ b/src/boot/boot2.s
@@ -18,11 +18,11 @@
        .code16
        .section .boot2,"a"
 
-       .set drive_number, 0x7bec
-       # reset floppy drive
-       xor %ax, %ax
-       movb drive_number, %dl
-       int $0x13
+       # make sure any BIOS call didn't re-enable interrupts
+       cli
+
+       mov $0x13, %ax
+       int $0x10
 
        # load initial GDT/IDT
        lgdt (gdt_lim)
@@ -43,11 +43,8 @@
        mov %ax, %gs
        mov %ax, %fs
 
-       mov $0x18, %ax
-       ltr %ax
-
-       #movb $10, %al
-       #call ser_putchar
+       movb $10, %al
+       call ser_putchar
 
        call clearscr
 
@@ -57,13 +54,15 @@
        # enable A20 line
        call enable_a20
 
+       call logohack
+
        cli
        hlt
 
 hello: .asciz "Switched to 32bit\n"
 
        .align 4
-gdt_lim: .word 31
+gdt_lim: .word 23
 gdt_base:.long gdt
 
        .align 4
@@ -81,11 +80,6 @@ gdt: # 0: null segment
        # 2: data - base:0, lim:4g, G:4k, 32bit, avl, pres|app, dpl:0, type:data/rw
        .long 0x0000ffff
        .long 0x00cf9200
-       # 3: dummy TSS - base:tss, lim:103, type avail 32bit TSS, byte-granular
-       .short 103
-       .short tss
-       .short 0x8900
-       .short 0
 
 
        .align 8
@@ -97,10 +91,7 @@ idt: .space 104
        .short 0x8f00
        .short 0
 
-       .align 4
-tss:   .space 104
-
-gpf_msg: .asciz "GPF "
+gpf_msg: .asciz "GP fault "
 
 prot_fault:
        mov (%esp), %eax
@@ -115,24 +106,19 @@ prot_fault:
        hlt
 
 ena20_msg: .asciz "A20 line enabled\n"
-foo_msg: .asciz "Foo\n"
 
 enable_a20:
-       mov $foo_msg, %esi
-       call putstr
-       jmp .La20done
-
        call test_a20
-       jnc .La20done
+       jnc a20done
        call enable_a20_kbd
        call test_a20
-       jnc .La20done
+       jnc a20done
        call enable_a20_fast
        call test_a20
-       jnc .La20done
+       jnc a20done
        # keep trying ... we can't do anything useful without A20 anyway
        jmp enable_a20
-.La20done:
+a20done:
        mov $ena20_msg, %esi
        call putstr
        ret
@@ -146,8 +132,7 @@ test_a20:
        subl $0xbaadf00d, (%ebx)
        ret
 
-ena20_fast_msg: .asciz "Attempting fast A20 enable\n"
-
+       # enable A20 line through port 0x92 (fast A20)
 enable_a20_fast:
        mov $ena20_fast_msg, %esi
        call putstr
@@ -157,6 +142,10 @@ enable_a20_fast:
        out %al, $0x92
        ret
 
+ena20_fast_msg: .asciz "Attempting fast A20 enable\n"
+
+
+       # enable A20 line through the keyboard controller
        .set KBC_DATA_PORT, 0x60
        .set KBC_CMD_PORT, 0x64
        .set KBC_STATUS_PORT, 0x64
@@ -166,9 +155,6 @@ enable_a20_fast:
        .set KBC_STAT_OUT_RDY, 0x01
        .set KBC_STAT_IN_FULL, 0x02
 
-ena20_kbd_msg: .asciz "Attempting KBD A20 enable\n"
-
-       # enable A20 line through the keyboard controller
 enable_a20_kbd:
        mov $ena20_kbd_msg, %esi
        call putstr
@@ -181,6 +167,8 @@ enable_a20_kbd:
        out %al, $KBC_DATA_PORT
        ret
 
+ena20_kbd_msg: .asciz "Attempting KBD A20 enable\n"
+
        # wait until the keyboard controller is ready to accept another byte
 kbc_wait_write:
        in $KBC_STATUS_PORT, %al
@@ -241,14 +229,14 @@ print_num:
        mov $numbuf + 16, %esi
        movb $0, (%esi)
        mov $10, %ebx
-.Lconvloop:
+convloop:
        xor %edx, %edx
        div %ebx
        add $48, %dl
        dec %esi
        mov %dl, (%esi)
        cmp $0, %eax
-       jnz .Lconvloop
+       jnz convloop
 
        call putstr
 
@@ -305,9 +293,9 @@ ser_putchar:
 0:     mov %al, %ah
        # wait until the transmit register is empty
        mov $UART_LSTAT, %dx
-.Lwait:        in %dx, %al
+wait:  in %dx, %al
        and $LST_TREG_EMPTY, %al
-       jz .Lwait
+       jz wait
        mov $UART_DATA, %dx
        mov %ah, %al
        out %al, %dx
@@ -316,13 +304,9 @@ ser_putchar:
        ret
 
 
-       .code16
 logohack:
-       mov $0x13, %ax
-       int $0x10
-
        # copy palette
-       mov $logo_pal, %si
+       mov $logo_pal, %esi
        xor %cl, %cl
 
 0:     xor %eax, %eax
@@ -331,98 +315,84 @@ logohack:
        outb %al, %dx
        inc %dx
        # red
-       movb (%si), %al
-       inc %si
+       movb (%esi), %al
+       inc %esi
        shr $2, %al
        outb %al, %dx
        # green
-       movb (%si), %al
-       inc %si
+       movb (%esi), %al
+       inc %esi
        shr $2, %al
        outb %al, %dx
        # blue
-       movb (%si), %al
-       inc %si
+       movb (%esi), %al
+       inc %esi
        shr $2, %al
        outb %al, %dx
        add $1, %cl
        jnc 0b
 
        # copy pixels
-       pushw $0xa000
-       pop %es
-       mov $logo_pix, %eax
-       shr $4, %eax
-       #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
+       mov $sintab, %ebp
+       mov $logo_pix, %esi
+frameloop:
+       mov $0xa0000, %edi
+       movl $0, yval
+yloop:
+       movl $0, xval
+xloop:
+       # calc src scanline address -> ebx
+       xor %ecx, %ecx
+       mov yval, %ebx
+       shl $2, %ebx
+       add frameno, %ebx
+       and $0xff, %ebx
+       mov (%ebp, %ebx), %cl
+       shr $5, %ecx
+
+       mov yval, %eax
+       add %ecx, %eax
        # bounds check
-       cmp $200, %ax
+       cmp $200, %eax
        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
+       mov $199, %eax
+
+0:     mov %eax, %ebx
+       shl $8, %eax
+       shl $6, %ebx
+       add %eax, %ebx
+
+       # calc src x offset -> eax
+       xor %ecx, %ecx
+       mov xval, %eax
+       shl $2, %eax
+       add frameno, %eax
+       and $0xff, %eax
+       mov (%ebp, %eax), %cl
+       shr $5, %ecx
+
+       mov xval, %eax
+       add %ecx, %eax
        # bounds check
-       cmp $320, %ax
+       cmp $320, %eax
        jl 0f
-       mov $319, %ax
-
-0:     mov %ax, %si
+       mov $319, %eax
 
-       mov %gs:(%bx, %si), %al
+0:     add %eax, %ebx
+       mov (%ebx, %esi), %al
 
-       mov %al, %es:(%di)
-       inc %di
+       mov %al, (%edi)
+       inc %edi
 
-       incw xval
-       cmpw $320, xval
-       jnz .Lxloop
+       incl xval
+       cmpl $320, xval
+       jnz xloop
 
-       incw yval
-       cmpw $200, yval
-       jnz .Lyloop
+       incl yval
+       cmpl $200, yval
+       jnz yloop
 
-       incw frameno
+       incl frameno
 
        # wait vsync
        mov $0x3da, %dx
@@ -432,27 +402,11 @@ logohack:
 0:     in %dx, %al
        and $8, %al
        jz 0b
-       jmp .Lframeloop
-
-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
-
+       jmp frameloop
 
+xval: .long 0
+yval: .long 0
+frameno: .long 0
 
 numbuf: .space 16