diff --git a/sw/device/lib/handler.h b/sw/device/lib/handler.h
index 6af92d3..50dfadf 100644
--- a/sw/device/lib/handler.h
+++ b/sw/device/lib/handler.h
@@ -16,4 +16,114 @@
   kIdMax = 31
 } exc_id_t;
 
+// The RISC-V interrupt vector will not include the addresses of the handlers,
+// instead, it includes (uncompressed) instructions. Thus the interrupt vector
+// will include `j <interrupt handler name>` for each handler.
+//
+// The only requirement on the symbol in the jump is that it must be correctly
+// aligned. If the processor supports the C extension, this can be 2-byte
+// aligned, but 4-byte aligned is compatible with all RISC-V processors.
+//
+// If the processor is not using interrupt vectoring, then there will be a
+// single address where interrupts jump to, which will either contain a function
+// (which will need to be aligned), or will contain a jump to a function, again
+// which will need to be aligned.
+//
+// You only need to use this ABI for handlers that are the first function called
+// in an interrupt handler. Subsequent functions can just use the regular RISC-V
+// calling convention.
+#define INTERRUPT_HANDLER_ABI __attribute__((aligned(4), interrupt))
+
+// The following `handler_*` functions have weak definitions, provided by
+// `handler.c`. This weak definition can be overriden at link-time by providing
+// an additional non-weak definition of each function. Executables and libraries
+// must not contain more than one weak definition of the same symbol.
+
+/**
+ * Default exception handler.
+ *
+ * `handler.c` provides a weak definition of this symbol, which can be overriden
+ * at link-time by providing an additional non-weak definition.
+ */
+INTERRUPT_HANDLER_ABI void handler_exception(void);
+
+/**
+ * SW IRQ handler.
+ *
+ * `handler.c` provides a weak definition of this symbol, which can be overriden
+ * at link-time by providing an additional non-weak definition.
+ */
+INTERRUPT_HANDLER_ABI void handler_irq_software(void);
+
+/**
+ * Timer IRQ handler.
+ *
+ * `handler.c` provides a weak definition of this symbol, which can be overriden
+ * at link-time by providing an additional non-weak definition.
+ */
+INTERRUPT_HANDLER_ABI void handler_irq_timer(void);
+
+/**
+ * external IRQ handler.
+ *
+ * `handler.c` provides a weak definition of this symbol, which can be overriden
+ * at link-time by providing an additional non-weak definition.
+ */
+INTERRUPT_HANDLER_ABI void handler_irq_external(void);
+
+/**
+ * Instruction access fault.
+ *
+ * Called by default implementation of `handler_exception`. If that function is
+ * overriden, this function may not be called.
+ *
+ * `handler.c` provides a weak definition of this symbol, which can be overriden
+ * at link-time by providing an additional non-weak definition.
+ */
+void handler_instr_acc_fault(void);
+
+/**
+ * Illegal Instruction fault.
+ *
+ * Called by default implementation of `handler_exception`. If that function is
+ * overriden, this function may not be called.
+ *
+ * `handler.c` provides a weak definition of this symbol, which can be overriden
+ * at link-time by providing an additional non-weak definition.
+ */
+void handler_instr_ill_fault(void);
+
+/**
+ * Breakpoint handler.
+ *
+ * Called by default implementation of `handler_exception`. If that function is
+ * overriden, this function may not be called.
+ *
+ * `handler.c` provides a weak definition of this symbol, which can be overriden
+ * at link-time by providing an additional non-weak definition.
+ */
+void handler_bkpt(void);
+
+/**
+ * Load store unit fault.
+ *
+ * Called by default implementation of `handler_exception`. If that function is
+ * overriden, this function may not be called.
+ *
+ * `handler.c` provides a weak definition of this symbol, which can be overriden
+ * at link-time by providing an additional non-weak definition.
+ */
+void handler_lsu_fault(void);
+
+/**
+ * Exception call handler.
+ *
+ * Called by default implementation of `handler_exception`. If that function is
+ * overriden, this function may not be called.
+ *
+ * `handler.c` provides a weak definition of this symbol, which can be overriden
+ * at link-time by providing an additional non-weak definition.
+ */
+void handler_ecall(void);
+
 #endif