From 16ffb9d5c70a64285cd84b3599698ee0297d1d0c Mon Sep 17 00:00:00 2001 From: John Tsiombikas Date: Thu, 19 Apr 2018 07:23:07 +0300 Subject: [PATCH] Fixed dobule-faults: the BIOS 13h calls enabled interrupts behind my back Protected mode setup works. --- src/boot/boot.s | 28 +++---- src/boot/boot2.s | 222 ++++++++++++++++++++++-------------------------------- 2 files changed, 102 insertions(+), 148 deletions(-) diff --git a/src/boot/boot.s b/src/boot/boot.s index 554f5a2..f17766b 100644 --- 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 --- 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 -- 1.7.10.4