1 files changed, 86 insertions, 0 deletions
diff --git a/xxx/boot2/common_pm.asm b/xxx/boot2/common_pm.asm
new file mode 100644
index 0000000..c96e1a8
--- /dev/null
+++ b/xxx/boot2/common_pm.asm
@@ -0,0 +1,86 @@
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;;;;; Miguel's FoolOS Helper Functions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;
+;print_string_pm
+;print_hex_pm
+;
+;
+;
+
+[bits 32]
+
+VIDEO_MEM equ 0xb8000
+WHITE_ON_BLACK equ 0x0f
+
+;global data
+STR_HEX_OUT_PM:
+    db "0x0000",0
+
+; print [ebx] at ecx
+print_string_pm:
+    pusha
+    mov edx, VIDEO_MEM
+    add edx,ecx
+    print_string_pm_loop:
+    mov al,[ebx]
+    mov ah, WHITE_ON_BLACK
+    cmp al,0
+    je print_string_pm_done
+    mov [edx],ax
+    add ebx,1
+    add edx,2
+    jmp print_string_pm_loop
+
+print_string_pm_done:
+    popa
+    ret
+
+;print_hex_pm routine (dx) at ecx
+;will print the value of the bx register as hex to the screen
+print_hex_pm:
+
+    pusha
+   
+
+    ;begin with last hex val (hex_out[5])
+    mov bx,STR_HEX_OUT_PM+5
+
+    ;lets loop throuth all 4 'digits'
+    print_hex_pm_loop:
+
+    ;get least significan hex digit to cx
+    mov cx,dx
+    and cx,0x000F
+
+    ;check range (0-9 vs a-f)
+    cmp cx,10
+    jl print_hex_pm_setnum
+
+    ;set hex a-f
+    mov al,'A'-10		
+    add al,cl
+    jmp print_hex_pm_al
+
+    ;set hex 0-9
+    print_hex_pm_setnum:
+    mov al,'0'		
+    add al,cl
+
+    ; set hex_out[bx] to al
+    print_hex_pm_al:
+    mov [bx],al
+
+    ;proceed with the next significant hex 'digit'
+    dec bx
+    shr dx,4
+
+    ;check if finished (otherwise loop)
+    cmp bx,STR_HEX_OUT_PM+1
+    jne print_hex_pm_loop
+
+    ;output complete hex string and return to caller
+    popa
+    mov bx,STR_HEX_OUT_PM
+    call print_string_pm
+    ret