explain some of the .option directives in _enter()

src/main.rs

@@ -15,11 +15,16 @@ unsafe extern "C" fn _enter() -> ! {
     use core::arch::asm;
     asm!(
         // before we use the `la` pseudo-instruction for the first time,
-        //  we need to set `gp` (google linker relaxation)
+        // we need to set `gp` (google linker relaxation)
-        ".option push",
+        ".option push", // pushes the current option stack
-        ".option norelax",
+        ".option norelax", // disable relaxation so we can properly set `gp`
+        // this instruction compiles to:
+        //   1:
+        //     auipc gp, %pcrel_hi(_global_pointer)
+        //     addi  gp, gp, %pcrel_lo(1b)
+        // if relaxation were on, this would simply be `mv gp, gp` or `addi gp, gp, 0`
         "la gp, _global_pointer",
-        ".option pop",
+        ".option pop", // pops the current option stack
 
         // set the stack pointer
         "la sp, _init_stack_top",
@@ -67,7 +72,9 @@ extern "C" fn start() -> ! {
 }
 
 #[panic_handler]
-fn on_panic(_info: &PanicInfo) -> ! {
+fn on_panic(info: &PanicInfo) -> ! {
+    println!("{}", info);
+
     loop {}
 }
 

src/script.ld

@@ -14,7 +14,7 @@ PHDRS {
 }
 
 SECTIONS {
-  . = ORIGIN(ram); # start at 0x8000_0000
+  . = ORIGIN(ram); # start at 0x8000_0000 (DRAM)
 
   .text : { # put code first
     *(.text.init) # start with anything in the .text.init section