fbdev/arm: Export acorndata_8x8 font symbol for bootloader

The text display code used in the Risc PC kernel image decompression
code uses arch/arm/boot/compressed/font.c, which includes
lib/fonts/font_acorn_8x8.c, which further includes <linux/font.h>.

Since commit 97df8960240a ("lib/fonts: Provide helpers for calculating
glyph pitch and size") <linux/font.h> contains inline functions that
require __do_div64, which is not linked into the ARM kernel
decompressor. This makes Risc PC zImages fail to build.

Resolve this issue by defining the BOOTLOADER symbol and use it to avoid
a static declaration of the acorndata_8x8 symbol. That way it can be
referenced by the arm bootloader, and other static math functions and
symbols (like __do_div64) stay static and don't get unneccesary included
in the ARM kernel bootloader decompressor object file.

Fixes: 97df8960240a ("lib/fonts: Provide helpers for calculating glyph pitch and size")
Reported-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index a159120d1e42e2ccbd91e76482bf6c46c3e977ed..e3f550d6285786c8405b16768255af87b4dc8222 100644 (file)
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -157,4 +157,4 @@ $(obj)/piggy_data: $(obj)/../Image FORCE
 
 $(obj)/piggy.o: $(obj)/piggy_data
 
-CFLAGS_font.o := -Dstatic=
+CFLAGS_font.o := -DBOOTLOADER

diff --git a/lib/fonts/font_acorn_8x8.c b/lib/fonts/font_acorn_8x8.c
index 36c51016769d4141bd762b6dfa9710ccb493ef32..4ff52c79f8c4d64910b3af9c104597228fa8d86a 100644 (file)
--- a/lib/fonts/font_acorn_8x8.c
+++ b/lib/fonts/font_acorn_8x8.c
@@ -5,7 +5,12 @@
 
 #define FONTDATAMAX 2048
 
+#ifdef BOOTLOADER
+/* The acorndata_8x8 symbol is needed by the ARM bootloader too. */
+const struct font_data acorndata_8x8 = {
+#else
 static const struct font_data acorndata_8x8 = {
+#endif
 { 0, 0, FONTDATAMAX, 0 }, {
 /* 00 */  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* ^@ */
 /* 01 */  0x7e, 0x81, 0xa5, 0x81, 0xbd, 0x99, 0x81, 0x7e, /* ^A */