rtc

README.md

@@ -29,6 +29,9 @@ Hello world programs that run without an operating system.
             1.  [Interrupt zero divide](interrupt_zero_divide.S)
         1.  in
             1.  [in keyboard](in_keyboard.S)
+            1.  [in PIT (TODO)](in_pit.S)
+            1.  [in RTC](in_rtc.S)
+            1.  [in mouse (TODO)](in_mouse.S)
     1.  APM
         1.  [APM shutdown](apm_shutdown.S)
         1.  [APM shutdown 2](apm_shutdown2.S)

common.h

@@ -84,6 +84,15 @@ letter:
 end:
 .endm
 
+#define PRINT_HEX(reg) \
+    HEX(<reg>);\
+    PUTC(%al);\
+    PUTC(%bl)
+
+#define PRINT_NEWLINE \
+    PUTC($0x0A);\
+    PUTC($0x0D)
+
 /*
 Print a null terminated string.
 

in.md

@@ -0,0 +1,8 @@
+# in
+
+TODO http://wiki.osdev.org/CMOS#Getting_Current_Date_and_Time_from_RTC says:
+
+    /* since the 0x80 bit of al is not set, NMI is active */
+    out 0x70,al
+
+What does it mean?

in_keyboard.S

@@ -9,9 +9,14 @@ Scancode tables: TODO: official specs?
 - http://flint.cs.yale.edu/cs422/doc/art-of-asm/pdf/APNDXC.PDF
 - https://en.wikipedia.org/wiki/Scancode
 
-TODO Where does the 0x60 come from? http://wiki.osdev.org/I/O_Ports has a small list.
+TODO Where does the 0x60 come from?
+
+- http://wiki.osdev.org/I/O_Ports
+- http://stackoverflow.com/questions/14194798/is-there-a-specification-of-x86-i-o-port-assignment
 
 TODO Possible to do this with the interrupt table instead of `in`?
+
+TODO understand http://wiki.osdev.org/PS2_Keyboard
 */
 
 #include "common.h"
@@ -20,14 +25,12 @@ BEGIN
     /* TODO why CLI makes no difference? We are not using interrupts? */
     /*cli*/
 loop:
+    /* Store the scancode to al. */
     in $0x60, %al
     cmp %al, %cl
     jz loop
     mov %al, %cl
-    HEX(<%al>)
-    PUTC(%al)
-    PUTC(%bl)
-    PUTC($0x0A)
-    PUTC($0x0D)
+    PRINT_HEX(%al)
+    PRINT_NEWLINE
     jmp loop
 END

in_mouse.S

@@ -0,0 +1,10 @@
+/*
+TODO http://wiki.osdev.org/Mouse_Input
+
+I am so going to make a pixel drawing program with this.
+*/
+
+#include "common.h"
+BEGIN
+hlt
+END

in_pit.S

@@ -0,0 +1,10 @@
+/*
+TODO http://wiki.osdev.org/PIT
+
+Going to use in 0x40
+*/
+
+#include "common.h"
+BEGIN
+hlt
+END

in_rtc.S

@@ -0,0 +1,73 @@
+/*
+TODO http://wiki.osdev.org/RTC
+
+Kenrel 4.2 usage: https://github.com/torvalds/linux/blob/v4.2/arch/x86/kernel/rtc.c#L121
+
+http://stackoverflow.com/questions/1465927/how-can-i-access-system-time-using-nasm
+*/
+
+#include "common.h"
+BEGIN
+
+.equ RTCaddress, 0x70
+.equ RTCdata, 0x71
+
+update_in_progress:
+    mov $10, %al
+    out %al, $RTCaddress
+    in $RTCdata, %al
+    testb $0x80, %al
+    jne update_in_progress
+
+    /* Second. */
+    mov $0, %al
+    out %al, $RTCaddress
+    in $RTCdata, %al
+
+    /* Only print if second changed. */
+    cmp %al, %cl
+    je update_in_progress
+    mov %al, %cl
+
+    PRINT_HEX(%al)
+    PUTC($0x20)
+
+    /* Minute. */
+    mov $0x02, %al
+    out %al, $RTCaddress
+    in $RTCdata, %al
+    PRINT_HEX(%al)
+    PUTC($0x20)
+
+    /* Hour. */
+    mov $0x04, %al
+    out %al, $RTCaddress
+    in $RTCdata, %al
+    PRINT_HEX(%al)
+    PUTC($0x20)
+
+    /* Day. */
+    mov $0x07, %al
+    out %al, $RTCaddress
+    in $RTCdata, %al
+    PRINT_HEX(%al)
+    PUTC($0x20)
+
+    /* Month. */
+    mov $0x08, %al
+    out %al, $RTCaddress
+    in $RTCdata, %al
+    PRINT_HEX(%al)
+    PUTC($0x20)
+
+    /* Year. */
+    mov $0x09, %al
+    out %al, $RTCaddress
+    in $RTCdata, %al
+    PRINT_HEX(%al)
+    PRINT_NEWLINE
+
+    jmp update_in_progress
+
+hlt
+END

interrupt.S

@@ -6,19 +6,25 @@ Should print the characters 'ab' to screen.
 TODO: is STI not needed because this interrupt is not maskable?
 
 TODO: use IDTR as a base. Is the initial value 0 guaranteed?
+
+TODO: interrupt priority: order looks like: 0, 1, 2, 8, 9, 10, 11, 12, 13, 14, 15, 3, 4, 5, 6, 7
+
+## iret
+
+Returns to the next instruction to be executed
+before the interrupt came in.
 */
 
 #include "common.h"
 BEGIN
     CLEAR
     movw $handler, 0x00
-    movw $0x00, 0x02
+    movw %cs, 0x02
     int $0
     PUTC($0x62)
     jmp end
 handler:
     PUTC($0x61)
-    /* Returns to the int instruction. */
     iret
 end:
     hlt

interrupt_zero_divide.S

@@ -6,8 +6,8 @@ Same as doing an `int $0`.
 BEGIN
     CLEAR
     movw $handler, 0x00
-    movw $0x00, 0x02
-    mov $0x00, %ax
+    movw %cs, 0x02
+    mov $0, %ax
     div %ax
     jmp fail
 handler:

template.S

@@ -1,3 +1,7 @@
+/*
+
+*/
+
 #include "common.h"
 BEGIN
 hlt

uefi/README.md

@@ -2,22 +2,17 @@
 
 Successor for BIOS.
 
-TODO get a hello world program working.
+TODO get a hello world program working:
 
 - http://www.rodsbooks.com/efi-programming/hello.html Best source so far: allowed me to compile the hello world! TODO: how to run it now on QEMU and real hardware?
 - https://fedoraproject.org/wiki/Using_UEFI_with_QEMU
 - https://wiki.ubuntu.com/UEFI/OVMF
 
-Sources:
-
-- https://wiki.archlinux.org/index.php/Unified_Extensible_Firmware_Interface
-- http://wiki.osdev.org/UEFI
-
 Running without image gives the UEFI shell, and a Linux kernel image booted fine with it: http://unix.stackexchange.com/a/228053/32558 , so we just need to generate the image.
 
-OVMF.fd IA32 r15214 downloaded from: https://sourceforge.net/projects/edk2/files/OVMF/OVMF-IA32-r15214.zip/download
+OVMF.fd IA32 r15214 downloaded from: https://sourceforge.net/projects/edk2/files/OVMF/OVMF-IA32-r15214.zip/download Included in-source for convenience, even though it is ugly.
 
-Included in-source for convenience, even though it is ugly.
+UEFI offers a large API. The POSIX C library has been ported to it, and there is some talk about Python running on it (through that POSIX lib)?
 
 ## Shell
 
@@ -34,3 +29,9 @@ Exit the shell.
 Enter a filesystem.
 
 TODO: how to make it visible in the first place?
+
+## Bibliography
+
+- https://www.youtube.com/watch?v=V2aq5M3Q76U hardcore kernel dev Matthew Garrett saying how bad UEFI is
+- https://wiki.archlinux.org/index.php/Unified_Extensible_Firmware_Interface
+- http://wiki.osdev.org/UEFI