Infinite loop, rm .elf output

.gitignore

@@ -1,5 +1,6 @@
 *.bin
 *.efi
+*.elf
 *.img
 *.iso
 *.o

bios_one_char.S

@@ -1,5 +1,8 @@
-# Print a single `@` character with the BIOS.
-# More minimal than the hello world.
+/*
+Print a single `@` character with the BIOS.
+More minimal than the hello world.
+*/
+
 #include "common.h"
 BEGIN
 mov $0x40, %al

infinite_loop.S

@@ -0,0 +1,11 @@
+/*
+This is a common alternative to `hlt`.
+
+It likely wastes more energy? But is less prone to being interrupted than `hlt`.
+*/
+
+#include "common.h"
+BEGIN
+loop:
+jmp loop
+END

multiboot/README.md

@@ -25,4 +25,4 @@ GRUB leaves the application into a well defined starting state.
 
 It seems that Linux does not implement Multiboot natively, but GRUB supports it as an exception: <http://stackoverflow.com/questions/17909429/booting-a-non-multiboot-kernel-with-grub2>
 
-Use `grub-mkrescue` to make a multiboot file into a bootable disk.
+Use `grub-mkrescue` and `grub-mkdisk` to make a multiboot file into a bootable ISO or disk.

multiboot/hello-world/Makefile

@@ -1,11 +1,12 @@
+# main.elf is the main output: the multiboot file.
 main.elf: entry.o main.o
 	ld -m elf_i386 -nostdlib -T linker.ld -o '$@' $^
 
 entry.o: entry.asm
-	nasm -f elf '$<' -o '$@'
+	nasm -f elf32 '$<' -o '$@'
 
 main.o: main.c
-	gcc -c -m32 -std=c99 -ffreestanding -fno-builtin -Os -Wall -Wextra -o '$@' '$<'
+	gcc -c -m32 -std=c99 -ffreestanding -fno-builtin -Os -o '$@' -Wall -Wextra '$<'
 
 clean:
 	rm -f *.elf *.o

multiboot/hello-world/isodir/boot/grub/grub.cfg

@@ -0,0 +1,3 @@
+menuentry "main" {
+	multiboot /boot/main.bin
+}

template.S

@@ -0,0 +1,4 @@
+#include "common.h"
+BEGIN
+hlt
+END