From 9b22a6965579ea1867aea291d910c96f386b518b Mon Sep 17 00:00:00 2001
From: Brett Weiland <brett_weiland@bpcspace.com>
Date: Tue, 24 Aug 2021 14:09:29 -0500
Subject: major backup 8.24.21

---
 src/kernel/io.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 src/kernel/io.c

(limited to 'src/kernel/io.c')

diff --git a/src/kernel/io.c b/src/kernel/io.c
new file mode 100644
index 0000000..1974c35
--- /dev/null
+++ b/src/kernel/io.c
@@ -0,0 +1,24 @@
+#include <io.h>
+#include <stdint.h>
+//these functions are assumed not to be time-sensitive.
+void outb_wait(uint16_t port, uint8_t value) {
+  outb(port, value);
+  io_wait(); 
+}
+
+void read_msr(uint32_t addr, uint64_t *value) {
+  uint32_t low, high;
+  asm volatile("rdmsr" : "=a"(low), "=d"(high) : "c"(addr));
+  *value = low | ((uint64_t)high << 32);
+}
+
+void write_msr(uint32_t addr, uint64_t value) {
+  uint32_t low = value & UINT32_MAX;
+  uint32_t high = value >> 32;
+  asm volatile("wrmsr"::"a"(low), "d"(high), "c"(addr));
+}
+
+void hlt() {
+  asm("cli\nhlt");
+}
+
-- 
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