From d373d2f3986d0f19e4f7d7d8517d382bc3eda99b Mon Sep 17 00:00:00 2001
From: Freya Murphy <freya@freyacat.org>
Date: Mon, 7 Oct 2024 19:33:05 -0400
Subject: [PATCH] the

---
 kern/entry.S   | 10 +++++-----
 kern/monitor.c | 13 +++++++++++++
 lib/printfmt.c |  8 +++-----
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/kern/entry.S b/kern/entry.S
index 9550bbb..808ac11 100644
--- a/kern/entry.S
+++ b/kern/entry.S
@@ -3,16 +3,16 @@
 #include <inc/mmu.h>
 #include <inc/memlayout.h>
 
-# Shift Right Logical 
+# Shift Right Logical
 #define SRL(val, shamt)		(((val) >> (shamt)) & ~(-1 << (32 - (shamt))))
 
 
 ###################################################################
-# The kernel (this code) is linked at address ~(KERNBASE + 1 Meg), 
+# The kernel (this code) is linked at address ~(KERNBASE + 1 Meg),
 # but the bootloader loads it at address ~1 Meg.
-#	
+#
 # RELOC(x) maps a symbol x from its link address to its actual
-# location in physical memory (its load address).	 
+# location in physical memory (its load address).
 ###################################################################
 
 #define	RELOC(x) ((x) - KERNBASE)
@@ -91,6 +91,6 @@ spin:	jmp	spin
 	.globl		bootstack
 bootstack:
 	.space		KSTKSIZE
-	.globl		bootstacktop   
+	.globl		bootstacktop
 bootstacktop:
 
diff --git a/kern/monitor.c b/kern/monitor.c
index e137e92..95686d0 100644
--- a/kern/monitor.c
+++ b/kern/monitor.c
@@ -57,6 +57,19 @@ mon_kerninfo(int argc, char **argv, struct Trapframe *tf)
 int
 mon_backtrace(int argc, char **argv, struct Trapframe *tf)
 {
+	uint32_t *bp = (uint32_t *) read_ebp();
+	uint32_t ip;
+
+	cprintf("Stack backtrace:\n");
+
+	do {
+		ip = * (bp + 1);
+		cprintf("ebp %08x  eip %08x  args", bp, ip);
+		for (int i = 2; i < 7; i++)
+			cprintf(" %08x", * (bp + i));
+		cprintf("\n");
+	} while ((bp = (uint32_t *) *bp));
+
 	// Your code here.
 	return 0;
 }
diff --git a/lib/printfmt.c b/lib/printfmt.c
index 28e01c9..b1de635 100644
--- a/lib/printfmt.c
+++ b/lib/printfmt.c
@@ -205,11 +205,9 @@ vprintfmt(void (*putch)(int, void*), void *putdat, const char *fmt, va_list ap)
 
 		// (unsigned) octal
 		case 'o':
-			// Replace this with your code.
-			putch('X', putdat);
-			putch('X', putdat);
-			putch('X', putdat);
-			break;
+			num = getuint(&ap, lflag);
+			base = 8;
+			goto number;
 
 		// pointer
 		case 'p':