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authorChristoph Niedermaier <cniedermaier@dh-electronics.de>2018-11-05 11:48:35 +0300
committerJonathan Corbet <corbet@lwn.net>2018-11-06 17:36:22 +0300
commit8bed5a5cfc3317217f4b4ddad8044cbdd13d5a20 (patch)
tree17192f617896cd0afc7bbd22e84d01eaaa2f01b2 /Documentation/EDID
parentd2f112a5681078aa2150f218074f76617fea4d74 (diff)
downloadlinux-8bed5a5cfc3317217f4b4ddad8044cbdd13d5a20.tar.xz
Docs/EDID: Calculate CRC while building the code
The previous version made it necessary to first generate an EDID data set without correct CRC and then to fix the CRC in a second step. This patch adds the CRC calculation to the makefile in such a way that a correct EDID data set is generated in a single build step. Successfully tested with all existing and a couple of new data sets. Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.de> Reviewed-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/EDID')
-rw-r--r--Documentation/EDID/1024x768.S1
-rw-r--r--Documentation/EDID/1280x1024.S1
-rw-r--r--Documentation/EDID/1600x1200.S1
-rw-r--r--Documentation/EDID/1680x1050.S1
-rw-r--r--Documentation/EDID/1920x1080.S1
-rw-r--r--Documentation/EDID/800x600.S1
-rw-r--r--Documentation/EDID/HOWTO.txt9
-rw-r--r--Documentation/EDID/Makefile15
8 files changed, 13 insertions, 17 deletions
diff --git a/Documentation/EDID/1024x768.S b/Documentation/EDID/1024x768.S
index ff4013e5fa49..4aed3f9ab88a 100644
--- a/Documentation/EDID/1024x768.S
+++ b/Documentation/EDID/1024x768.S
@@ -39,6 +39,5 @@
#define ESTABLISHED_TIMING2_BITS 0x08 /* Bit 3 -> 1024x768 @60 Hz */
#define HSYNC_POL 0
#define VSYNC_POL 0
-#define CRC 0x55
#include "edid.S"
diff --git a/Documentation/EDID/1280x1024.S b/Documentation/EDID/1280x1024.S
index ce0e85be379e..b26dd424cad7 100644
--- a/Documentation/EDID/1280x1024.S
+++ b/Documentation/EDID/1280x1024.S
@@ -39,6 +39,5 @@
/* No ESTABLISHED_TIMINGx_BITS */
#define HSYNC_POL 1
#define VSYNC_POL 1
-#define CRC 0xa0
#include "edid.S"
diff --git a/Documentation/EDID/1600x1200.S b/Documentation/EDID/1600x1200.S
index 5eeb751ebe1b..0d091b282768 100644
--- a/Documentation/EDID/1600x1200.S
+++ b/Documentation/EDID/1600x1200.S
@@ -39,6 +39,5 @@
/* No ESTABLISHED_TIMINGx_BITS */
#define HSYNC_POL 1
#define VSYNC_POL 1
-#define CRC 0x9d
#include "edid.S"
diff --git a/Documentation/EDID/1680x1050.S b/Documentation/EDID/1680x1050.S
index ec679507e33b..7dfed9a33eab 100644
--- a/Documentation/EDID/1680x1050.S
+++ b/Documentation/EDID/1680x1050.S
@@ -39,6 +39,5 @@
/* No ESTABLISHED_TIMINGx_BITS */
#define HSYNC_POL 1
#define VSYNC_POL 1
-#define CRC 0x26
#include "edid.S"
diff --git a/Documentation/EDID/1920x1080.S b/Documentation/EDID/1920x1080.S
index e0657af801dd..d6ffbba28e95 100644
--- a/Documentation/EDID/1920x1080.S
+++ b/Documentation/EDID/1920x1080.S
@@ -39,6 +39,5 @@
/* No ESTABLISHED_TIMINGx_BITS */
#define HSYNC_POL 1
#define VSYNC_POL 1
-#define CRC 0x05
#include "edid.S"
diff --git a/Documentation/EDID/800x600.S b/Documentation/EDID/800x600.S
index b6853b2db869..a5616588de08 100644
--- a/Documentation/EDID/800x600.S
+++ b/Documentation/EDID/800x600.S
@@ -36,6 +36,5 @@
#define ESTABLISHED_TIMING1_BITS 0x01 /* Bit 0: 800x600 @ 60Hz */
#define HSYNC_POL 1
#define VSYNC_POL 1
-#define CRC 0xc2
#include "edid.S"
diff --git a/Documentation/EDID/HOWTO.txt b/Documentation/EDID/HOWTO.txt
index 7d05a7d30a79..539871c3b785 100644
--- a/Documentation/EDID/HOWTO.txt
+++ b/Documentation/EDID/HOWTO.txt
@@ -47,12 +47,3 @@ EDID:
#define YBLANK vtotal-vdisp
#define YOFFSET vsyncstart-vdisp
#define YPULSE vsyncend-vsyncstart
-
-The CRC value in the last line
- #define CRC 0x55
-also is a bit tricky. After a first version of the binary data set is
-created, it must be checked with the "edid-decode" utility which will
-most probably complain about a wrong CRC. Fortunately, the utility also
-displays the correct CRC which must then be inserted into the source
-file. After the make procedure is repeated, the EDID data set is ready
-to be used.
diff --git a/Documentation/EDID/Makefile b/Documentation/EDID/Makefile
index 17763ca3f12b..85a927dfab02 100644
--- a/Documentation/EDID/Makefile
+++ b/Documentation/EDID/Makefile
@@ -15,10 +15,21 @@ clean:
%.o: %.S
@cc -c $^
-%.bin: %.o
+%.bin.nocrc: %.o
@objcopy -Obinary $^ $@
-%.bin.ihex: %.o
+%.crc: %.bin.nocrc
+ @list=$$(for i in `seq 1 127`; do head -c$$i $^ | tail -c1 \
+ | hexdump -v -e '/1 "%02X+"'; done); \
+ echo "ibase=16;100-($${list%?})%100" | bc >$@
+
+%.p: %.crc %.S
+ @cc -c -DCRC="$$(cat $*.crc)" -o $@ $*.S
+
+%.bin: %.p
+ @objcopy -Obinary $^ $@
+
+%.bin.ihex: %.p
@objcopy -Oihex $^ $@
@dos2unix $@ 2>/dev/null