From 1cd47da742565a5ffce234e505f85c16a1ca69f5 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Sat, 15 Nov 2025 15:00:16 -0500
Subject: kern/amd64: cpu: Write boot message on startup

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 sys/arch/amd64/cpu/boot.S | 12 ++++++++++++
 sys/arch/amd64/io/uart.S  |  1 +
 2 files changed, 13 insertions(+)

(limited to 'sys/arch')

diff --git a/sys/arch/amd64/cpu/boot.S b/sys/arch/amd64/cpu/boot.S
index 3ce82e6..a6961be 100644
--- a/sys/arch/amd64/cpu/boot.S
+++ b/sys/arch/amd64/cpu/boot.S
@@ -29,6 +29,7 @@
 
     .globl _start
     .extern uart_init
+    .extern uart_write
     .extern gdt_load
     .extern GDTR
 _start:
@@ -41,9 +42,20 @@ _start:
     lea GDTR(%rip), %rdi    /* Our GDTR */
     call gdt_load           /* Load our GDT */
 
+    lea bootmsg(%rip), %rdi
+    movq bootmsg_len, %rsi
+    call uart_write
 1:  cli
     hlt
     jmp 1b
 
+    .section .rodata
+bootmsg:
+    .ascii "[ preparing since 2025 ]\n"
+    .ascii "[ 00:00 delta @ crev : 89 seconds]\n"
+    .ascii "** booting rv7 ...\n"
+    .byte 0x00
+bootmsg_len:    .quad . - bootmsg
+
 /* vim: ft=gas :
 */
diff --git a/sys/arch/amd64/io/uart.S b/sys/arch/amd64/io/uart.S
index fee06c4..8e190ed 100644
--- a/sys/arch/amd64/io/uart.S
+++ b/sys/arch/amd64/io/uart.S
@@ -65,6 +65,7 @@ uart_init:
     pop %r12
     retq
 
+    .globl uart_write
 uart_write:
     /*
      * void uart_write(const char *s, size_t len);
-- 
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