From d78b60f868f40cefe3ac958800ac828f2eafc81c Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Tue, 4 Jun 2024 23:32:33 +0200
Subject: Supervisor trap & claim MSI

---
 kernel/strap.s | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 kernel/strap.s

(limited to 'kernel/strap.s')

diff --git a/kernel/strap.s b/kernel/strap.s
new file mode 100644
index 0000000..079c579
--- /dev/null
+++ b/kernel/strap.s
@@ -0,0 +1,81 @@
+.option norvc
+.section .text
+
+.global ktrap
+
+.set FRAME_SIZE, 4 * 31
+
+.global strap
+strap:
+    addi        sp, sp, -FRAME_SIZE
+
+    sw          x1,  (0  * 4)(sp)
+    sw          x2,  (1  * 4)(sp)
+    sw          x3,  (2  * 4)(sp)
+    sw          x4,  (3  * 4)(sp)
+    sw          x5,  (4  * 4)(sp)
+    sw          x6,  (5  * 4)(sp)
+    sw          x7,  (6  * 4)(sp)
+    sw          x8,  (7  * 4)(sp)
+    sw          x9,  (8  * 4)(sp)
+    sw          x10, (9  * 4)(sp)
+    sw          x11, (10 * 4)(sp)
+    sw          x12, (11 * 4)(sp)
+    sw          x13, (12 * 4)(sp)
+    sw          x14, (13 * 4)(sp)
+    sw          x15, (14 * 4)(sp)
+    sw          x16, (15 * 4)(sp)
+    sw          x17, (16 * 4)(sp)
+    sw          x18, (17 * 4)(sp)
+    sw          x19, (18 * 4)(sp)
+    sw          x20, (19 * 4)(sp)
+    sw          x21, (20 * 4)(sp)
+    sw          x22, (21 * 4)(sp)
+    sw          x23, (22 * 4)(sp)
+    sw          x24, (23 * 4)(sp)
+    sw          x25, (24 * 4)(sp)
+    sw          x26, (25 * 4)(sp)
+    sw          x27, (26 * 4)(sp)
+    sw          x28, (27 * 4)(sp)
+    sw          x29, (28 * 4)(sp)
+    sw          x30, (29 * 4)(sp)
+    sw          x31, (30 * 4)(sp)
+        
+    csrr        a0, scause
+    call        ktrap
+
+    lw          x1,  (0  * 4)(sp)
+    lw          x2,  (1  * 4)(sp)
+    lw          x3,  (2  * 4)(sp)
+    lw          x4,  (3  * 4)(sp)
+    lw          x5,  (4  * 4)(sp)
+    lw          x6,  (5  * 4)(sp)
+    lw          x7,  (6  * 4)(sp)
+    lw          x8,  (7  * 4)(sp)
+    lw          x9,  (8  * 4)(sp)
+    lw          x10, (9  * 4)(sp)
+    lw          x11, (10 * 4)(sp)
+    lw          x12, (11 * 4)(sp)
+    lw          x13, (12 * 4)(sp)
+    lw          x14, (13 * 4)(sp)
+    lw          x15, (14 * 4)(sp)
+    lw          x16, (15 * 4)(sp)
+    lw          x17, (16 * 4)(sp)
+    lw          x18, (17 * 4)(sp)
+    lw          x19, (18 * 4)(sp)
+    lw          x20, (19 * 4)(sp)
+    lw          x21, (20 * 4)(sp)
+    lw          x22, (21 * 4)(sp)
+    lw          x23, (22 * 4)(sp)
+    lw          x24, (23 * 4)(sp)
+    lw          x25, (24 * 4)(sp)
+    lw          x26, (25 * 4)(sp)
+    lw          x27, (26 * 4)(sp)
+    lw          x28, (27 * 4)(sp)
+    lw          x29, (28 * 4)(sp)
+    lw          x30, (29 * 4)(sp)
+    lw          x31, (30 * 4)(sp)
+    
+    addi        sp, sp, FRAME_SIZE
+    
+    sret
-- 
cgit