ops, forgot to load the 16bit IDT, also serial print of IVT

diff --git a/.gitignore b/.gitignore
index 65d44d9..a4c4df9 100644 (file)
--- a/.gitignore
+++ b/.gitignore
@@ -4,4 +4,4 @@
 *.bin
 *.img
 *.efi
-disasm
+disasm*

diff --git a/Makefile b/Makefile
index 198f1d8..5f0c29f 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -31,3 +31,6 @@ debug: disk.img
 
 disasm: bootx64.efi
        ndisasm -b 64 -o 0x1000 -e 4096 $< >$@
+
+disasm16: bootx64.efi
+       ndisasm -b 16 -o 0x1000 -e 4096 $< >$@

diff --git a/efitest.asm b/efitest.asm
index ae804dd..333b095 100644 (file)
--- a/efitest.asm
+++ b/efitest.asm
@@ -1,7 +1,8 @@
-; vi:ft=nasm:
        bits 64
        org 1000h
 
+%include "serial.inc"
+
 BOOT_SERVICES          equ 96
 BOOT_GET_MEMORY_MAP    equ 56
 BOOT_EXIT_BOOT_SERVICES        equ 232
@@ -52,28 +53,10 @@ start:
        push qword start32
        retfq
 
-
-.hang: jmp .hang
-
 get_rip:
        mov rax, [rsp]
        ret
 
-
-UART_DATA              equ 0x3f8
-UART_DIVLO             equ 0x3f8
-UART_DIVHI             equ 0x3f9
-UART_FIFO              equ 0x3fa
-UART_LCTL              equ 0x3fb
-UART_MCTL              equ 0x3fc
-UART_LSTAT             equ 0x3fd
-DIV_9600               equ 115200 / 9600
-LCTL_8N1               equ 0x03
-LCTL_DLAB              equ 0x80
-FIFO_ENABLE_CLEAR      equ 0x07
-MCTL_DTR_RTS_OUT2      equ 0x0b
-LST_TREG_EMPTY         equ 0x20
-
        ; serial port setup
 setup_serial:
        ; set clock divisor
@@ -101,36 +84,7 @@ setup_serial:
        ret
 
 
-       align 8
-efihandle dq 0
-systab dq 0
-; memory map data
-mmap_size dq 4096
-mmap_key dq 0
-mmap_descsz dq 0
-mmap_descver dq 0
-
-       align 4096
-mmapbuf: times 4096 db 0
-
-str_hello db 'hello!',13,10,0
-
-       align 4
-gdtlim dw 31
-gdtbase        dq gdt
-
-       align 8
-gdt:   ; 0: null segment
-       dd 0, 0
-       ; 1: code - base:0, lim:4g, G:4k, 32bit, avl, pres|app, dpl:0, type:code/non-conf/rd
-       dd 0x0000ffff
-       dd 0x00cf9a00
-       ; 2: data - base:0, lim:4g, G:4k, 32bit, avl, pres|app, dpl:0, type:data/rw
-       dd 0x0000ffff
-       dd 0x00cf9200
-       ; 3: code16
-       dd 0x0000ffff
-       dd 0x00009a00
+; ----------- 32bit code ----------
 
        bits 32
 start32:
@@ -153,40 +107,14 @@ start32:
        and eax, 0fffffeffh
        wrmsr
 
+       ; load 16bit IVT descriptor
+       cli     ; just to make sure
+       lidt [rmidt]
+
        ; load 16bit code segment and jump to 16bit code
        jmp 0x18:start16
 
-.hang: hlt
-       jmp .hang
-
-       
-ser_putchar:
-       mov ah, al
-       ; wait until transmit register is empty
-       mov dx, UART_LSTAT
-.wait: in al, dx
-       and al, LST_TREG_EMPTY
-       jz .wait
-       mov dx, UART_DATA
-       mov al, ah
-       out dx, al
-       ret
-
-ser_putstr:
-       mov al, [esi]
-       test al, al
-       jz .done
-       call ser_putchar
-       inc esi
-       jmp ser_putstr
-.done: ret
-
-
-       align 4
-       ; real mode IDTR pseudo-descriptor pointing to the IVT at addr 0
-       dw 0
-rmidt: dw 3ffh
-       dd 0
+; ---------- 16bit real mode code ----------
 
        bits 16
 start16:
@@ -208,9 +136,11 @@ start16:
        mov ss, ax
        xor sp, sp
 
+       call print_ivt
+
        ; run 16bit video bios test
        mov ax, 13h
-       ;int 10h
+       int 10h
 
        mov ax, 0a000h
        mov es, ax
@@ -222,5 +152,119 @@ start16:
 .hang: hlt
        jmp .hang
 
+print_ivt:
+       xor bx, bx
+.loop: mov ax, bx
+       shr ax, 2
+       call printhex8
+       mov al, ' '
+       call ser_putchar
+       mov ax, [bx + 2]        ; segment
+       call printhex16
+       mov al, ':'
+       call ser_putchar
+       mov ax, [bx]            ; offset
+       call printhex16
+       mov al, 13
+       call ser_putchar
+       mov al, 10
+       call ser_putchar
+       add bx, 4
+
+       cmp bx, 64 << 2
+       jnz .loop
+       ret
+
+hexdig db '0123456789abcdef'
+
+printhex8:
+       push bx
+       rol al, 4
+       mov bx, ax
+       and bx, 0fh
+       mov cx, ax
+       mov al, [bx + hexdig]
+       call ser_putchar
+       mov ax, cx
+       rol al, 4
+       mov bx, ax
+       and bx, 0fh
+       mov al, [bx + hexdig]
+       call ser_putchar
+       pop bx
+       ret
+
+printhex16:
+       push ax
+       mov al, ah
+       call printhex8
+       pop ax
+       call printhex8
+       ret
+
+ser_putchar:
+       mov ah, al
+       ; wait until transmit register is empty
+       mov dx, UART_LSTAT
+.wait: in al, dx
+       and al, LST_TREG_EMPTY
+       jz .wait
+       mov dx, UART_DATA
+       mov al, ah
+       out dx, al
+       ret
+
+ser_putstr:
+       mov al, [si]
+       test al, al
+       jz .done
+       call ser_putchar
+       inc si
+       jmp ser_putstr
+.done: ret
+
+
+; ---------- data ------------
+
+       align 8
+efihandle dq 0
+systab dq 0
+; memory map data
+mmap_size dq 4096
+mmap_key dq 0
+mmap_descsz dq 0
+mmap_descver dq 0
+
+       align 4096
+mmapbuf: times 4096 db 0
+
+str_hello db 'hello!',13,10,0
+
+       align 4
+gdtlim dw 31
+gdtbase        dq gdt
+
+       align 8
+gdt:   ; 0: null segment
+       dd 0, 0
+       ; 1: code - base:0, lim:4g, G:4k, 32bit, avl, pres|app, dpl:0, type:code/non-conf/rd
+       dd 0x0000ffff
+       dd 0x00cf9a00
+       ; 2: data - base:0, lim:4g, G:4k, 32bit, avl, pres|app, dpl:0, type:data/rw
+       dd 0x0000ffff
+       dd 0x00cf9200
+       ; 3: code16
+       dd 0x0000ffff
+       dd 0x00009a00
+
+
+       align 4
+       ; real mode IDTR pseudo-descriptor pointing to the IVT at addr 0
+       dw 0
+rmidt: dw 3ffh
+       dd 0
+
+
        align 4
 end:
+; vi:ft=nasm:

diff --git a/serial.inc b/serial.inc
new file mode 100644 (file)
index 0000000..74fcf0b
--- /dev/null
+++ b/serial.inc
@@ -0,0 +1,15 @@
+UART_DATA              equ 0x3f8
+UART_DIVLO             equ 0x3f8
+UART_DIVHI             equ 0x3f9
+UART_FIFO              equ 0x3fa
+UART_LCTL              equ 0x3fb
+UART_MCTL              equ 0x3fc
+UART_LSTAT             equ 0x3fd
+DIV_9600               equ 115200 / 9600
+LCTL_8N1               equ 0x03
+LCTL_DLAB              equ 0x80
+FIFO_ENABLE_CLEAR      equ 0x07
+MCTL_DTR_RTS_OUT2      equ 0x0b
+LST_TREG_EMPTY         equ 0x20
+
+; vi:ft=nasm: