Keyboard Work - setting up PLIC, UART, Interrupts

src/boot/entry.S

@@ -1,22 +1,20 @@
-.section .text
+.section .text.boot
 .global _start
 _start:
-    la sp, stack_top      # Set up the stack pointer
-    la t0, trap_entry     # Set up the trap handler
-    csrw mtvec, t0        # Set the trap vector to our trap handler
-    li t0, 0x00006000     # Load the mask for FS bits. enable float
-    csrs mstatus, t0      # Set the FS bits to 11 (Dirty/Initial). enable float
-    call kmain            # Jump to our C code
+    # 1. Set up the stack pointer using the symbol from our linker script
+    la sp, stack_top      
+
+    # 2. Set up the trap handler (pointing to the one in traps.S)
+    la t0, trap_entry     
+    csrw mtvec, t0        
+
+    # 3. Enable FPU (Floating Point)
+    li t0, 0x00006000     
+    csrs mstatus, t0      
+
+    # 4. Jump to C
+    call kmain            
+
 loop:
-    wfi                   # Wait for Interrupt (saves CPU)
-    j loop                # Infinite loop if C returns
-.align 4
-trap_entry:
-    csrr a0, mcause    # Argument 1: mcause
-    csrr a1, mepc      # Argument 2: mepc
-    j handle_trap
-.section .bss
-.align 16
-stack_low:
-    .skip 4096            # 4KB of stack space
-stack_top:
+    wfi                   
+    j loop