update resources

resources.md

@@ -4,6 +4,8 @@
 - <https://www.nasm.us/xdoc/2.13.01/nasmdoc.pdf>
 - <https://wiki.osdev.org/Real_Mode>
 - <https://www.eecg.utoronto.ca/~amza/www.mindsec.com/files/x86regs.html>
+- <https://en.wikibooks.org/wiki/X86_Assembly/16,_32,_and_64_Bits>
+- <https://www.plantation-productions.com/Webster/www.artofasm.com/DOS/ch04/CH04-2.html>
 
 ## Boot sequence
 - <https://wiki.osdev.org/Boot_Sequence>
@@ -19,9 +21,13 @@
 - <https://wiki.osdev.org/MBR_%28x86%29>
 - <https://wiki.osdev.org/Disk_access_using_the_BIOS_(INT_13h)>
 - <https://wiki.osdev.org/Ralf_Brown%27s_Interrupt_List>
+- <https://web.archive.org/web/20160619063203/http://www.ctyme.com/intr/rb-0621.htm>
 
 ## VGA
 - <https://en.wikipedia.org/wiki/Video_Graphics_Array>
 - <https://os.phil-opp.com/vga-text-mode/>
 - <https://mendelson.org/wpdos/videomodes.txt>
 
+## ELF
+- <https://wiki.osdev.org/ELF>
+- <https://wiki.osdev.org/ELF_Tutorial>