[U-Boot] fs/fat: device not booting since conversion to dir iterators
Since commit 8eafae209c35932d9a6560809c55ee4641534236 my mx53cx9020_defconfig stopped booting. I could "fix" that commit with this patch: diff --git a/fs/fat/fat.c b/fs/fat/fat.c index bbba7947ee..b99ec85097 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -1035,6 +1035,9 @@ int file_fat_ls(const char *dir) int files = 0, dirs = 0; int ret;
+ //fix_fat + disk_read(0, PREFETCH_BLOCKS, do_fat_read_at_block); + ret = fat_itr_root(itr, &fsdata); if (ret) return ret;
Since then file_fat_ls() has been moved/replaced with fs_ls_generic(). So I had to adjust that workaround. And added the dummy disk_read() into fs_opendir() callback: diff --git a/fs/fat/fat.c b/fs/fat/fat.c index 7fe78439cf..be6eaeb68e 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -1155,6 +1155,7 @@ int fat_opendir(const char *filename, struct fs_dir_stream **dirsp) if (!dir) return -ENOMEM;
+ disk_read(0, PREFETCH_BLOCKS, do_fat_read_at_block); ret = fat_itr_root(&dir->itr, &dir->fsdata); if (ret) goto fail_free_dir;
It seems important to read into do_fat_read_at_block. If I allocate a temporary buffer and read into that one, I still can't boot. That seems strange to me as, I couldn't find any uninitialized access to do_fat_read_at_block anywhere.
Another workaround is to disable CMD_FAT: diff --git a/configs/mx53cx9020_defconfig b/configs/mx53cx9020_defconfig index b704f32fbf..2d560aabc1 100644 --- a/configs/mx53cx9020_defconfig +++ b/configs/mx53cx9020_defconfig @@ -15,7 +15,7 @@ CONFIG_CMD_MII=y CONFIG_CMD_PING=y CONFIG_CMD_EXT2=y CONFIG_CMD_EXT4=y -CONFIG_CMD_FAT=y +CONFIG_DOS_PARTITION=y CONFIG_CMD_FS_GENERIC=y CONFIG_OF_CONTROL=y CONFIG_ENV_IS_IN_MMC=y
My device is powered by an i.MX53 and configured to load u-boot from sdcard. That sdcard doesn't have any FAT partition on it: Disk /dev/mmcblk0: 471 MiB, 493879296 bytes, 964608 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0xbbd9d8f6
Device Boot Start End Sectors Size Id Type /dev/mmcblk0p1 * 2048 489471 487424 238M 83 Linux
Maybe my sdcard layout is broken, too. If you need any additional info or have any idea whatelse I could try, please let me know.
Thanks in advance, Patrick Beckhoff Automation GmbH & Co. KG | Managing Director: Dipl. Phys. Hans Beckhoff Registered office: Verl, Germany | Register court: Guetersloh HRA 7075
From: Patrick Brünn Sent: Donnerstag, 30. November 2017 12:22
Since commit 8eafae209c35932d9a6560809c55ee4641534236 my mx53cx9020_defconfig stopped booting. ... It seems important to read into do_fat_read_at_block. If I allocate a temporary buffer and read into that one, I still can't boot. That seems strange to me as, I couldn't find any uninitialized access to do_fat_read_at_block anywhere.
I believe I finally tracked it down to the linker.
Without accessing do_fat_read_at_block within fat.c, I find .bss. do_fat_read_at_block as "discarded input section" in my u-boot.map
With a patch like this: diff --git a/fs/fat/fat.c b/fs/fat/fat.c index d16883fa10..8e70fdbc8d 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -1157,6 +1157,7 @@ int fat_opendir(const char *filename, struct fs_dir_stream **dirsp) return -ENOMEM; memset(dir, 0, sizeof(*dir));
+ if (do_fat_read_at_block[0]) + printf("value doesn't matter, the access is important\n"); + ret = fat_itr_root(&dir->itr, &dir->fsdata); if (ret) goto fail_free_dir;
The section isn't discarded and my board boots again.
Another workaround would be: diff --git a/arch/arm/config.mk b/arch/arm/config.mk index 124b44a337..02f61fcc3c 100644 --- a/arch/arm/config.mk +++ b/arch/arm/config.mk @@ -17,7 +17,7 @@ CFLAGS_NON_EFI := -fno-pic -ffixed-r9 -ffunction-sections -fdata-sections CFLAGS_EFI := -fpic -fshort-wchar
LDFLAGS_FINAL += --gc-sections -PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections \ +PLATFORM_RELFLAGS += -ffunction-sections \ -fno-common -ffixed-r9 PLATFORM_RELFLAGS += $(call cc-option, -msoft-float) \ $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,))
Or a hack like: diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds index 37d4c605ac..b916cbc733 100644 --- a/arch/arm/cpu/u-boot.lds +++ b/arch/arm/cpu/u-boot.lds @@ -219,6 +219,7 @@ SECTIONS }
.bss_end __bss_limit (OVERLAY) : { + KEEP(*(.bss.do_fat_read_at_block)); KEEP(*(.__bss_end)); }
I also tried to mark do_fat_read_at_block as: volatile, __used and/or __attribute__((externally_visible))
This doesn't help.
Moving it into fat_write.c doesn't help either(with/without static)
My toolchain is: ~/u-boot$ arm-linux-gnueabihf-gcc -v Using built-in specs. COLLECT_GCC=arm-linux-gnueabihf-gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/arm-linux-gnueabihf/6/lto-wrapper Target: arm-linux-gnueabihf Configured with: ../src/configure -v --with-pkgversion='Debian 6.3.0-18' --with-bugurl=file:///usr/share/doc/gcc-6/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-6 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libitm --disable-libquadmath --enable-plugin --enable-default-pie --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-6-armhf-cross/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-6-armhf-cross --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-6-armhf-cross --with-arch-directory=arm --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libgcj --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-sjlj-exceptions --with-arch=armv7-a --with-fpu=vfpv3-d16 --with-float=hard --with-mode=thumb --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=arm-linux-gnueabihf --program-prefix=arm-linux-gnueabihf- --includedir=/usr/arm-linux-gnueabihf/include Thread model: posix gcc version 6.3.0 20170516 (Debian 6.3.0-18)
~/u-boot$ arm-linux-gnueabihf-ld -v GNU ld (GNU Binutils for Debian) 2.28
Does anyone have an idea what else I can try to prevent my linker from removing do_fat_read_at_block?
Regards, Patrick -- Beckhoff Automation GmbH & Co. KG | Managing Director: Dipl. Phys. Hans Beckhoff Registered office: Verl, Germany | Register court: Guetersloh HRA 7075
Hi Patrick,
On 13 December 2017 at 03:15, Patrick Brünn P.Bruenn@beckhoff.com wrote:
From: Patrick Brünn Sent: Donnerstag, 30. November 2017 12:22
Since commit 8eafae209c35932d9a6560809c55ee4641534236 my mx53cx9020_defconfig stopped booting. ... It seems important to read into do_fat_read_at_block. If I allocate a temporary buffer and read into that one, I still can't boot. That seems strange to me as, I couldn't find any uninitialized access to do_fat_read_at_block anywhere.
I believe I finally tracked it down to the linker.
Without accessing do_fat_read_at_block within fat.c, I find .bss. do_fat_read_at_block as "discarded input section" in my u-boot.map
With a patch like this: diff --git a/fs/fat/fat.c b/fs/fat/fat.c index d16883fa10..8e70fdbc8d 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -1157,6 +1157,7 @@ int fat_opendir(const char *filename, struct fs_dir_stream **dirsp) return -ENOMEM; memset(dir, 0, sizeof(*dir));
if (do_fat_read_at_block[0])printf("value doesn't matter, the access is important\n");ret = fat_itr_root(&dir->itr, &dir->fsdata); if (ret) goto fail_free_dir;The section isn't discarded and my board boots again.
Another workaround would be: diff --git a/arch/arm/config.mk b/arch/arm/config.mk index 124b44a337..02f61fcc3c 100644 --- a/arch/arm/config.mk +++ b/arch/arm/config.mk @@ -17,7 +17,7 @@ CFLAGS_NON_EFI := -fno-pic -ffixed-r9 -ffunction-sections -fdata-sections CFLAGS_EFI := -fpic -fshort-wchar
LDFLAGS_FINAL += --gc-sections -PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections \ +PLATFORM_RELFLAGS += -ffunction-sections \ -fno-common -ffixed-r9 PLATFORM_RELFLAGS += $(call cc-option, -msoft-float) \ $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,))
Or a hack like: diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds index 37d4c605ac..b916cbc733 100644 --- a/arch/arm/cpu/u-boot.lds +++ b/arch/arm/cpu/u-boot.lds @@ -219,6 +219,7 @@ SECTIONS }
.bss_end __bss_limit (OVERLAY) : {
KEEP(*(.bss.do_fat_read_at_block)); KEEP(*(.__bss_end)); }I also tried to mark do_fat_read_at_block as: volatile, __used and/or __attribute__((externally_visible))
This doesn't help.
Moving it into fat_write.c doesn't help either(with/without static)
My toolchain is: ~/u-boot$ arm-linux-gnueabihf-gcc -v Using built-in specs. COLLECT_GCC=arm-linux-gnueabihf-gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/arm-linux-gnueabihf/6/lto-wrapper Target: arm-linux-gnueabihf Configured with: ../src/configure -v --with-pkgversion='Debian 6.3.0-18' --with-bugurl=file:///usr/share/doc/gcc-6/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-6 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libitm --disable-libquadmath --enable-plugin --enable-default-pie --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-6-armhf-cross/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-6-armhf-cross --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-6-armhf-cross --with-arch-directory=arm --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libgcj --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-sjlj-exceptions --with-arch=armv7-a --with-fpu=vfpv3-d16 --with-float=hard --with-mode=thumb --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=arm-linux-gnueabihf --program-prefix=arm-linux-gnueabihf- --includedir=/usr/arm-linux-gnueabihf/include Thread model: posix gcc version 6.3.0 20170516 (Debian 6.3.0-18)
~/u-boot$ arm-linux-gnueabihf-ld -v GNU ld (GNU Binutils for Debian) 2.28
Does anyone have an idea what else I can try to prevent my linker from removing do_fat_read_at_block?
This doesn't seem to be used unless you have enabled CONFIG_FAT_WRITE. Have you?
I wonder if the problem is somewhere else, and the presence of this buffer is just moving things apart in the data space, and thus masking the problem?
Regards, Simon
Hi Simon,
From: sjg@google.com [mailto:sjg@google.com] On Behalf Of Simon Glass Sent: Dienstag, 19. Dezember 2017 16:42 Hi Patrick,
On 13 December 2017 at 03:15, Patrick Brünn P.Bruenn@beckhoff.com wrote:
From: Patrick Brünn Sent: Donnerstag, 30. November 2017 12:22
Since commit 8eafae209c35932d9a6560809c55ee4641534236 my mx53cx9020_defconfig stopped booting. ... It seems important to read into do_fat_read_at_block. If I allocate a temporary buffer and read into that one, I still can't boot. That seems strange to me as, I couldn't find any uninitialized access to do_fat_read_at_block anywhere.
I believe I finally tracked it down to the linker.
Without accessing do_fat_read_at_block within fat.c, I find .bss. do_fat_read_at_block as "discarded input section" in my u-boot.map
With a patch like this: diff --git a/fs/fat/fat.c b/fs/fat/fat.c index d16883fa10..8e70fdbc8d 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -1157,6 +1157,7 @@ int fat_opendir(const char *filename, struct
fs_dir_stream **dirsp)
return -ENOMEM; memset(dir, 0, sizeof(*dir));
if (do_fat_read_at_block[0])printf("value doesn't matter, the access is important\n");ret = fat_itr_root(&dir->itr, &dir->fsdata); if (ret) goto fail_free_dir;The section isn't discarded and my board boots again.
Another workaround would be: diff --git a/arch/arm/config.mk b/arch/arm/config.mk index 124b44a337..02f61fcc3c 100644 --- a/arch/arm/config.mk +++ b/arch/arm/config.mk @@ -17,7 +17,7 @@ CFLAGS_NON_EFI := -fno-pic -ffixed-r9 -ffunction-
sections -fdata-sections
CFLAGS_EFI := -fpic -fshort-wchar
LDFLAGS_FINAL += --gc-sections -PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections \ +PLATFORM_RELFLAGS += -ffunction-sections \ -fno-common -ffixed-r9 PLATFORM_RELFLAGS += $(call cc-option, -msoft-float) \ $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,))
Or a hack like: diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds index 37d4c605ac..b916cbc733 100644 --- a/arch/arm/cpu/u-boot.lds +++ b/arch/arm/cpu/u-boot.lds @@ -219,6 +219,7 @@ SECTIONS }
.bss_end __bss_limit (OVERLAY) : {
KEEP(*(.bss.do_fat_read_at_block)); KEEP(*(.__bss_end)); }I also tried to mark do_fat_read_at_block as: volatile, __used and/or __attribute__((externally_visible))
This doesn't help.
Moving it into fat_write.c doesn't help either(with/without static)
My toolchain is: ~/u-boot$ arm-linux-gnueabihf-gcc -v Using built-in specs. COLLECT_GCC=arm-linux-gnueabihf-gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/arm-linux-gnueabihf/6/lto-
wrapper
Target: arm-linux-gnueabihf Configured with: ../src/configure -v --with-pkgversion='Debian 6.3.0-18' --
with-bugurl=file:///usr/share/doc/gcc-6/README.Bugs --enable- languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program- suffix=-6 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib -- without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable- libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique- object --disable-libitm --disable-libquadmath --enable-plugin --enable- default-pie --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-6-armhf- cross/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj- 6-armhf-cross --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-6-armhf- cross --with-arch-directory=arm --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libgcj --with-target-system-zlib --enable-objc-gc=auto --enable- multiarch --disable-sjlj-exceptions --with-arch=armv7-a --with-fpu=vfpv3-d16 --with-float=hard --with-mode=thumb --enable-checking=release -- build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=arm-linux- gnueabihf --program-prefix=arm-linux-gnueabihf- --includedir=/usr/arm- linux-gnueabihf/include
Thread model: posix gcc version 6.3.0 20170516 (Debian 6.3.0-18)
~/u-boot$ arm-linux-gnueabihf-ld -v GNU ld (GNU Binutils for Debian) 2.28
Does anyone have an idea what else I can try to prevent my linker from
removing
do_fat_read_at_block?
This doesn't seem to be used unless you have enabled CONFIG_FAT_WRITE. Have you?
I wonder if the problem is somewhere else, and the presence of this buffer is just moving things apart in the data space, and thus masking the problem?
Yes, I hope I finally found it. Please see the first patch of this series[1]. Don't using that global variable anymore fixes my problem, according to the documentation it makes sense. Even if I am still not 100% sure. I just don't understand why this thing was working for so long for at least two boards. Does it make sense to you?
Thanks for your input, Patrick
[1] https://www.mail-archive.com/u-boot@lists.denx.de/msg272444.html
Beckhoff Automation GmbH & Co. KG | Managing Director: Dipl. Phys. Hans Beckhoff Registered office: Verl, Germany | Register court: Guetersloh HRA 7075
participants (2)
-
Patrick Brünn -
Simon Glass