From 6154318ab33b12fc481d94819c90b9aebf83045a Mon Sep 17 00:00:00 2001
From: 8infy <99danilt@gmail.com>
Date: Sun, 1 Sep 2024 19:36:17 +0300
Subject: [PATCH] kernel: add a helper to retrieve the bsp CPU

This is useful to be able to e.g. set affinity for the BSP CPU.
---
 kernel-src/arch/x86-64/main.c        | 4 ++++
 kernel-src/include/x86-64/arch/cpu.h | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/kernel-src/arch/x86-64/main.c b/kernel-src/arch/x86-64/main.c
index 654bdeba..a7ee64f0 100644
--- a/kernel-src/arch/x86-64/main.c
+++ b/kernel-src/arch/x86-64/main.c
@@ -124,3 +124,7 @@ void kernel_entry() {
 	sched_runinit();
 	sched_threadexit();
 }
+
+cpu_t *_bsp(void) {
+	return &bsp_cpu;
+}
diff --git a/kernel-src/include/x86-64/arch/cpu.h b/kernel-src/include/x86-64/arch/cpu.h
index 132bf8c4..26bda0fb 100644
--- a/kernel-src/include/x86-64/arch/cpu.h
+++ b/kernel-src/include/x86-64/arch/cpu.h
@@ -54,6 +54,8 @@ static inline uint16_t be_to_cpu_w(uint16_t w) {
 	return __builtin_bswap16(w);
 }
 
+cpu_t *_bsp(void);
+
 static inline cpu_t *_cpu() {
 	cpu_t *cpu;
 	asm volatile ("mov %%gs:0, %%rax" : "=a"(cpu) : : "memory");