From 10454f4cb624e9644939c12e4c3deb20c36f9ecc Mon Sep 17 00:00:00 2001
From: Mateusz Faderewski <sc@mateuszfaderewski.pl>
Date: Tue, 28 May 2024 01:10:28 +0200
Subject: [PATCH] another small cleanup

---
 sw/bootloader/src/exception.S | 20 +++++++++++++++-----
 sw/bootloader/src/exception.c |  8 ++++++--
 sw/bootloader/src/exception.h |  6 ++++--
 sw/bootloader/src/sc64.c      |  2 +-
 4 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/sw/bootloader/src/exception.S b/sw/bootloader/src/exception.S
index 3ba81e4..d26c7d2 100644
--- a/sw/bootloader/src/exception.S
+++ b/sw/bootloader/src/exception.S
@@ -33,11 +33,13 @@
 #define SP_OFFSET                   (232)
 #define S8_OFFSET                   (240)
 #define RA_OFFSET                   (248)
-#define C0_STATUS_OFFSET            (256)
-#define C0_CAUSE_OFFSET             (260)
-#define C0_EPC_OFFSET               (264)
-#define C0_BADVADDR_OFFSET          (272)
-#define SAVE_REGISTERS_SIZE         (280)
+#define HI_OFFSET                   (256)
+#define LO_OFFSET                   (264)
+#define C0_EPC_OFFSET               (272)
+#define C0_BADVADDR_OFFSET          (280)
+#define C0_STATUS_OFFSET            (288)
+#define C0_CAUSE_OFFSET             (292)
+#define SAVE_REGISTERS_SIZE         (296)
 
 
 .section .text.exception_vector
@@ -93,6 +95,10 @@ exception_handler:
     sd $sp, SP_OFFSET($k0)
     sd $s8, S8_OFFSET($k0)
     sd $ra, RA_OFFSET($k0)
+    mfhi $t0
+    mflo $t1
+    sd $t0, HI_OFFSET($k0)
+    sd $t1, LO_OFFSET($k0)
     .set at
 
     move $sp, $k0
@@ -130,6 +136,10 @@ exception_interrupt:
 
 exception_restore:
     .set noat
+    ld $t0, HI_OFFSET($k0)
+    ld $t1, LO_OFFSET($k0)
+    mthi $t0
+    mtlo $t1
     ld $at, AT_OFFSET($k0)
     ld $v0, V0_OFFSET($k0)
     ld $v1, V1_OFFSET($k0)
diff --git a/sw/bootloader/src/exception.c b/sw/bootloader/src/exception.c
index e4e0a3f..c8d7b4d 100644
--- a/sw/bootloader/src/exception.c
+++ b/sw/bootloader/src/exception.c
@@ -34,8 +34,10 @@ static const char *exception_get_description (uint8_t exception_code) {
 void exception_fatal_handler (uint32_t exception_code, exception_t *e) {
     display_init((uint32_t *) (&assets_sc64_logo_640_240_dimmed));
 
+    uint32_t exception_address = e->epc.u32 + (e->cr & C0_CR_BD ? 4 : 0);
+
     version_print();
-    display_printf("[ Unhandled exception ]\n");
+    display_printf("[ Unhandled exception ] @ 0x%08X\n", exception_address);
     display_printf("%s\n", exception_get_description(exception_code));
     display_printf(" pc: 0x%08lX  sr: 0x%08lX  cr: 0x%08lX  va: 0x%08lX\n", e->epc.u32, e->sr, e->cr, e->badvaddr.u32);
     display_printf(" zr: 0x%08lX  at: 0x%08lX  v0: 0x%08lX  v1: 0x%08lX\n", e->zr.u32, e->at.u32, e->v0.u32, e->v1.u32);
@@ -45,7 +47,9 @@ void exception_fatal_handler (uint32_t exception_code, exception_t *e) {
     display_printf(" s0: 0x%08lX  s1: 0x%08lX  s2: 0x%08lX  s3: 0x%08lX\n", e->s0.u32, e->s1.u32, e->s2.u32, e->s3.u32);
     display_printf(" s4: 0x%08lX  s5: 0x%08lX  s6: 0x%08lX  s7: 0x%08lX\n", e->s4.u32, e->s5.u32, e->s6.u32, e->s7.u32);
     display_printf(" t8: 0x%08lX  t9: 0x%08lX  k0: 0x%08lX  k1: 0x%08lX\n", e->t8.u32, e->t9.u32, e->k0.u32, e->k1.u32);
-    display_printf(" gp: 0x%08lX  sp: 0x%08lX  s8: 0x%08lX  ra: 0x%08lX\n\n", e->gp.u32, e->sp.u32, e->s8.u32, e->ra.u32);
+    display_printf(" gp: 0x%08lX  sp: 0x%08lX  s8: 0x%08lX  ra: 0x%08lX\n", e->gp.u32, e->sp.u32, e->s8.u32, e->ra.u32);
+    display_printf(" hi: 0x%016lX\n", e->hi.u64);
+    display_printf(" lo: 0x%016lX\n", e->lo.u64);
 
     while (true);
 }
diff --git a/sw/bootloader/src/exception.h b/sw/bootloader/src/exception.h
index 3a7a7a6..cc0f100 100644
--- a/sw/bootloader/src/exception.h
+++ b/sw/bootloader/src/exception.h
@@ -46,10 +46,12 @@ typedef struct {
     uint64_32_t sp;
     uint64_32_t s8;
     uint64_32_t ra;
-    uint32_t sr;
-    uint32_t cr;
+    uint64_32_t hi;
+    uint64_32_t lo;
     uint64_32_t epc;
     uint64_32_t badvaddr;
+    uint32_t sr;
+    uint32_t cr;
 } exception_t;
 
 
diff --git a/sw/bootloader/src/sc64.c b/sw/bootloader/src/sc64.c
index a48b5b5..d233b51 100644
--- a/sw/bootloader/src/sc64.c
+++ b/sw/bootloader/src/sc64.c
@@ -1,6 +1,6 @@
+#include "error.h"
 #include "io.h"
 #include "sc64.h"
-#include "error.h"
 
 
 typedef struct {