[PATCH] sandbox: implement DEBUG_LL support

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

We can't currently debug malloc() or early parts of the driver model on
sandbox, because we require both to allocate the sandbox console device.

To make debugging such early startup easier in future, add some simple
DEBUG_LL support.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 arch/sandbox/Kconfig                |  1 +
 arch/sandbox/Makefile               |  3 ++-
 arch/sandbox/include/asm/debug_ll.h | 16 ++++++++++++++++
 3 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 arch/sandbox/include/asm/debug_ll.h

diff --git a/arch/sandbox/Kconfig b/arch/sandbox/Kconfig
index a8bca8757f28..d3889fcac03c 100644
--- a/arch/sandbox/Kconfig
+++ b/arch/sandbox/Kconfig
@@ -16,6 +16,7 @@ config SANDBOX
 	select ARCH_HAS_STACK_DUMP if ASAN
 	select GENERIC_FIND_NEXT_BIT
 	select HAS_ARCH_SJLJ
+	select HAS_ASM_DEBUG_LL
 	default y
 
 config ARCH_TEXT_BASE
diff --git a/arch/sandbox/Makefile b/arch/sandbox/Makefile
index aee6bccc9c14..d5ba05ba866f 100644
--- a/arch/sandbox/Makefile
+++ b/arch/sandbox/Makefile
@@ -30,7 +30,8 @@ KBUILD_CFLAGS += -Dmalloc=barebox_malloc -Dcalloc=barebox_calloc \
 		-Dopendir=barebox_opendir -Dreaddir=barebox_readdir \
 		-Dclosedir=barebox_closedir -Dreadlink=barebox_readlink \
 		-Doptarg=barebox_optarg -Doptind=barebox_optind \
-		-Dsetjmp=barebox_setjmp -Dlongjmp=barebox_longjmp
+		-Dsetjmp=barebox_setjmp -Dlongjmp=barebox_longjmp \
+		-Dputchar=barebox_putchar
 
 machdirs := $(patsubst %,arch/sandbox/mach-%/,$(machine-y))
 
diff --git a/arch/sandbox/include/asm/debug_ll.h b/arch/sandbox/include/asm/debug_ll.h
new file mode 100644
index 000000000000..7bef8710581e
--- /dev/null
+++ b/arch/sandbox/include/asm/debug_ll.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_DEBUG_LL__
+#define __ASM_DEBUG_LL__
+
+#undef putchar
+
+static inline void PUTC_LL(char ch)
+{
+	int putchar(int c);
+	putchar(ch);
+}
+
+#define putchar barebox_putchar
+
+#endif /* __ASM_DEBUG_LL__ */
-- 
2.30.2