[Verse 1]
When the hardware needs attention from the CPU
It sends a signal through the interrupt queue
The processor stops what it's currently running
To handle the event that's just begun
A handler function waits to be called
Registered early when the system's installed
The kernel keeps a table of addresses neat
Where each interrupt has its own seat
[Chorus]
Register handlers, map the memory
Hardware talking directly to me
IRQ numbers in the vector table
Make the system fast and stable
Memory mapped I-O in view
Hardware interface breaking through
[Verse 2]
Memory-mapped means hardware looks like RAM
Same address space, same reading plan
No special instructions to reach the device
Just load and store, simple and nice
The kernel module claims its hardware space
Ioremap gives it a virtual place
Physical addresses get translated clean
To virtual ones the kernel's seen
[Chorus]
Register handlers, map the memory
Hardware talking directly to me
IRQ numbers in the vector table
Make the system fast and stable
Memory mapped I-O in view
Hardware interface breaking through
[Bridge]
Request IRQ with flags and name
Free it up when you're done with the game
Shared interrupts need careful thought
Check your device or handle naught
Volatile pointers for hardware reads
The compiler knows when memory feeds
Could change at any moment's time
Without the code that's in your line
[Verse 3]
Direct hardware from kernel space means power
Control the chips in their finest hour
But with great access comes responsibility
Handle errors with capability
Disable interrupts when sections are critical
Atomic operations keep data identical
The hardware waits while you're in control
Then interrupts resume their vital role
[Chorus]
Register handlers, map the memory
Hardware talking directly to me
IRQ numbers in the vector table
Make the system fast and stable
Memory mapped I-O in view
Hardware interface breaking through
[Outro]
From silicon to software's embrace
Interrupts bridge the hardware space
Handlers registered, memory mapped tight
Full-stack systems burning bright