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-rw-r--r--arch/arm/lib/Makefile2
-rw-r--r--arch/arm/lib/debug.S136
2 files changed, 138 insertions, 0 deletions
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 1ef2400..d74e4b8 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -48,6 +48,8 @@ ifndef CONFIG_ARM64
obj-y += cache-cp15.o
endif
+obj-$(CONFIG_DEBUG_LL) += debug.o
+
# For EABI conformant tool chains, provide eabi_compat()
ifneq (,$(findstring -mabi=aapcs-linux,$(PLATFORM_CPPFLAGS)))
extra-y += eabi_compat.o
diff --git a/arch/arm/lib/debug.S b/arch/arm/lib/debug.S
new file mode 100644
index 0000000..760ba74
--- /dev/null
+++ b/arch/arm/lib/debug.S
@@ -0,0 +1,136 @@
+/*
+ * linux/arch/arm/kernel/debug.S
+ *
+ * Copyright (C) 1994-1999 Russell King
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * 32-bit debugging code
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+ .text
+
+/*
+ * Some debugging routines (useful if you've got MM problems and
+ * printk isn't working). For DEBUGGING ONLY!!! Do not leave
+ * references to these in a production kernel!
+ */
+
+#if !defined(CONFIG_DEBUG_SEMIHOSTING)
+#include CONFIG_DEBUG_LL_INCLUDE
+#endif
+
+#ifdef CONFIG_MMU
+ .macro addruart_current, rx, tmp1, tmp2
+ addruart \tmp1, \tmp2, \rx
+ mrc p15, 0, \rx, c1, c0
+ tst \rx, #1
+ moveq \rx, \tmp1
+ movne \rx, \tmp2
+ .endm
+
+#else /* !CONFIG_MMU */
+ .macro addruart_current, rx, tmp1, tmp2
+ addruart \rx, \tmp1, \tmp2
+ .endm
+
+#endif /* CONFIG_MMU */
+
+/*
+ * Useful debugging routines
+ */
+ENTRY(printhex8)
+ mov r1, #8
+ b printhex
+ENDPROC(printhex8)
+
+ENTRY(printhex4)
+ mov r1, #4
+ b printhex
+ENDPROC(printhex4)
+
+ENTRY(printhex2)
+ mov r1, #2
+printhex: adr r2, hexbuf
+ add r3, r2, r1
+ mov r1, #0
+ strb r1, [r3]
+1: and r1, r0, #15
+ mov r0, r0, lsr #4
+ cmp r1, #10
+ addlt r1, r1, #'0'
+ addge r1, r1, #'a' - 10
+ strb r1, [r3, #-1]!
+ teq r3, r2
+ bne 1b
+ mov r0, r2
+ b printascii
+ENDPROC(printhex2)
+
+hexbuf: .space 16
+
+ .ltorg
+
+#ifndef CONFIG_DEBUG_SEMIHOSTING
+
+ENTRY(printascii)
+ addruart_current r3, r1, r2
+ b 2f
+1: waituart r2, r3
+ senduart r1, r3
+ busyuart r2, r3
+ teq r1, #'\n'
+ moveq r1, #'\r'
+ beq 1b
+2: teq r0, #0
+ ldrneb r1, [r0], #1
+ teqne r1, #0
+ bne 1b
+ mov pc, lr
+ENDPROC(printascii)
+
+ENTRY(printch)
+ addruart_current r3, r1, r2
+ mov r1, r0
+ mov r0, #0
+ b 1b
+ENDPROC(printch)
+
+#ifdef CONFIG_MMU
+ENTRY(debug_ll_addr)
+ addruart r2, r3, ip
+ str r2, [r0]
+ str r3, [r1]
+ mov pc, lr
+ENDPROC(debug_ll_addr)
+#endif
+
+#else
+
+ENTRY(printascii)
+ mov r1, r0
+ mov r0, #0x04 @ SYS_WRITE0
+ ARM( svc #0x123456 )
+ THUMB( svc #0xab )
+ mov pc, lr
+ENDPROC(printascii)
+
+ENTRY(printch)
+ adr r1, hexbuf
+ strb r0, [r1]
+ mov r0, #0x03 @ SYS_WRITEC
+ ARM( svc #0x123456 )
+ THUMB( svc #0xab )
+ mov pc, lr
+ENDPROC(printch)
+
+ENTRY(debug_ll_addr)
+ mov r2, #0
+ str r2, [r0]
+ str r2, [r1]
+ mov pc, lr
+ENDPROC(debug_ll_addr)
+
+#endif