OS Hello world

2024-05-13 12:21:59 +02:00
parent f95a85de00
commit 9160f2912e
6 changed files with 99 additions and 0 deletions
--- a/os/boot.S
+++ b/os/boot.S
@ -0,0 +1,31 @@
+.option norvc
+
+.section .init
+
+.equ UART_BASE, 0x10000000
+
+.global kstart
+kstart:
+    la        a0, _str
+    call      _println
+
+_halt:
+    wfi
+    j         _halt
+
+_println:
+    li        t0, UART_BASE
+_println_loop:
+    lb        t1, 0(a0)
+    beqz      t1, _end_println_loop
+    sb        t1, 0(t0)
+    addi      a0, a0, 1
+    j         _println_loop
+_end_println_loop:
+    li        t1, '\n'
+    sb        t1, 0(t0)
+    ret
+
+.section .rodata
+
+_str: .string "Hello, world!"