From f3ea4cd0c22f351d8dfffb0e937194c4b526b665 Mon Sep 17 00:00:00 2001
From: Christian Cunningham <cc@localhost>
Date: Mon, 3 Jan 2022 21:35:01 -0800
Subject: Added Stack ASM Functions

---
 src/drivers/uart.c | 12 ++++++------
 src/sys/core.h     | 22 ++++++++++++++++++++++
 src/util/status.c  |  3 +--
 3 files changed, 29 insertions(+), 8 deletions(-)

(limited to 'src')

diff --git a/src/drivers/uart.c b/src/drivers/uart.c
index cc1933e..142a5c3 100644
--- a/src/drivers/uart.c
+++ b/src/drivers/uart.c
@@ -1,11 +1,5 @@
 #include "../drivers/uart.h"
 
-void uart_hexn(unsigned long c_val)
-{
-	uart_hex(c_val);
-	uart_char('\n');
-}
-
 void uart_10(unsigned long val)
 {
 	unsigned long t = val;
@@ -22,3 +16,9 @@ void uart_10(unsigned long val)
 	}
 	uart_string(dptr);
 }
+
+void uart_hexn(unsigned long c_val)
+{
+	uart_hex(c_val);
+	uart_char('\n');
+}
diff --git a/src/sys/core.h b/src/sys/core.h
index 2ba2f16..fa9e1b5 100644
--- a/src/sys/core.h
+++ b/src/sys/core.h
@@ -19,6 +19,28 @@ static inline void delay(unsigned long cycles)
 			: "=r"(cycles): [cycles]"0"(cycles) : "cc");
 }
 
+static inline void preserveregs(void)
+{
+	asm volatile("push {r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11}");
+}
+
+static inline void restoreregs(void)
+{
+	asm volatile("pop {r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11}");
+}
+
+static inline void* getsp(void)
+{
+	void* out;
+	asm volatile ("mov %0, sp" : "=r"(out));
+	return out;
+}
+
+static inline void setsp(void* in)
+{
+	asm volatile ("mov sp, %0" :: "r"(in));
+}
+
 enum
 {
 	// The offset for the MMIO area
diff --git a/src/util/status.c b/src/util/status.c
index 1ac08e8..bd529da 100644
--- a/src/util/status.c
+++ b/src/util/status.c
@@ -141,8 +141,7 @@ void status(void)
 	write_char(&g_Drawer, '\n');
 	*/
 
-	unsigned long sp;
-	asm volatile ("mov %0, sp": "=r"(sp));
+	unsigned long sp = (unsigned long)getsp();
 	write_hex32(&g_Drawer, sp);
 
 	g_Drawer.x = x;
-- 
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