Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Mon, 2 Feb 2015, Pavel Machek wrote: On Tue 2015-01-27 10:16:24, Nicolas Pitre wrote: On Tue, 27 Jan 2015, Pavel Machek wrote: I would say, problem is because omap3-n900 binary DT is too large I agree. OK if that's the case, then your patch makes sense to me. It also seems we can have the temporary stack be larger than the initial stack just for atags_to_fdt. The stack size isn't the issue, but rather its location. We need to position it away from the DT data. The DT size is known and we could use that, plus some room for the insertion of new data coming from the ATAG conversion. Something like the following would be a more robust solution: Tested-by: Pavel Machek pa...@ucw.cz (Note, that in 3.19 dts for n900 got too big, so we are actually triggering old bugs. That means that this is a regression fix, and should go in ASAP). It is queued here: http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8294/1 Hmm, but it should be on kernel.org, not in private arm trees, as it fixes a regression. Russell, you are the ARM maintainer, can you push it to Linus? The patch is included in RMK's fixes branch already, along with other fixes. I suppose it'll make its way to Linus before v3.19 final. Nicolas -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Tue 2015-01-27 10:16:24, Nicolas Pitre wrote: On Tue, 27 Jan 2015, Pavel Machek wrote: I would say, problem is because omap3-n900 binary DT is too large I agree. OK if that's the case, then your patch makes sense to me. It also seems we can have the temporary stack be larger than the initial stack just for atags_to_fdt. The stack size isn't the issue, but rather its location. We need to position it away from the DT data. The DT size is known and we could use that, plus some room for the insertion of new data coming from the ATAG conversion. Something like the following would be a more robust solution: Tested-by: Pavel Machek pa...@ucw.cz (Note, that in 3.19 dts for n900 got too big, so we are actually triggering old bugs. That means that this is a regression fix, and should go in ASAP). It is queued here: http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8294/1 Hmm, but it should be on kernel.org, not in private arm trees, as it fixes a regression. Russell, you are the ARM maintainer, can you push it to Linus? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
I would say, problem is because omap3-n900 binary DT is too large
I agree.
OK if that's the case, then your patch makes sense to me. It also
seems we can have the temporary stack be larger than the initial
stack just for atags_to_fdt.
The stack size isn't the issue, but rather its location. We need to
position it away from the DT data. The DT size is known and we could
use that, plus some room for the insertion of new data coming from the
ATAG conversion.
Something like the following would be a more robust solution:
Tested-by: Pavel Machek pa...@ucw.cz
(Note, that in 3.19 dts for n900 got too big, so we are actually
triggering old bugs. That means that this is a regression fix, and
should go in ASAP).
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 68be901759..89718de9dd 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -263,16 +263,37 @@ restart:adr r0, LC0
* OK... Let's do some funky business here.
* If we do have a DTB appended to zImage, and we do have
* an ATAG list around, we want the later to be translated
- * and folded into the former here. To be on the safe side,
- * let's temporarily move the stack away into the malloc
- * area. No GOT fixup has occurred yet, but none of the
- * code we're about to call uses any global variable.
+ * and folded into the former here. No GOT fixup has occurred
+ * yet, but none of the code we're about to call uses any
+ * global variable.
*/
- add sp, sp, #0x1
+
+ /* Get the initial DTB size */
+ ldr r5, [r6, #4]
+#ifndef __ARMEB__
+ /* convert to little endian */
+ eor r1, r5, r5, ror #16
+ bic r1, r1, #0x00ff
+ mov r5, r5, ror #8
+ eor r5, r5, r1, lsr #8
+#endif
+ /* 50% DTB growth should be good enough */
+ add r5, r5, r5, lsr #1
+ /* preserve 64-bit alignment */
+ add r5, r5, #7
+ bic r5, r5, #7
+ /* clamp to 32KB min and 1MB max */
+ movsr1, r5, lsr #15
+ moveq r5, #(1 15)
+ movsr1, r5, lsr #20
+ movne r5, #(1 20)
+
+ /* Temporarily relocate the stack past the DTB work space */
+ add sp, sp, r5
stmfd sp!, {r0-r3, ip, lr}
mov r0, r8
mov r1, r6
- sub r2, sp, r6
+ mov r2, r5
bl atags_to_fdt
/*
@@ -285,11 +306,11 @@ restart:adr r0, LC0
bic r0, r0, #1
add r0, r0, #0x100
mov r1, r6
- sub r2, sp, r6
+ mov r2, r5
bleqatags_to_fdt
ldmfd sp!, {r0-r3, ip, lr}
- sub sp, sp, #0x1
+ sub sp, sp, r5
#endif
mov r8, r6 @ use the appended device tree
@@ -306,7 +327,7 @@ restart: adr r0, LC0
subsr1, r5, r1
addhi r9, r9, r1
- /* Get the dtb's size */
+ /* Get the current DTB size */
ldr r5, [r6, #4]
#ifndef __ARMEB__
/* convert r5 (dtb size) to little endian */
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures)
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line unsubscribe linux-omap in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Tue, 27 Jan 2015, Russell King - ARM Linux wrote: On Tue, Jan 27, 2015 at 10:16:24AM -0500, Nicolas Pitre wrote: On Tue, 27 Jan 2015, Pavel Machek wrote: (Note, that in 3.19 dts for n900 got too big, so we are actually triggering old bugs. That means that this is a regression fix, and should go in ASAP). It is queued here: http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8294/1 Irrespective of that patch, I commented on another thread (about adding the serial number to DT): | How about something a little more radical. | | Rather than trying to squeeze various ATAGs into DT, why don't we add a | standard ATAG to contain the DT and pass that through into the kernel. | This is IMHO how we _should_ have done the ATAG compatibility from the | start. | | That means we could get rid of most of the libfdt in the decompressor, | and instead resolve the differences in the kernel. That would allow us to get rid of all the FDT compatibility code in the decompressor, and when we encounter these special ATAGs, we can deal with them in the kernel instead of having to mess around with the DT. I'd also assume (although I haven't checked) that it would be much easier to add additional DT properties in the kernel environment, rather than in the rather restrictive decompressor environment. Well... I was initially against any ATAG-to-DT compatibility at all. IMHO the right solution is to update the bootloader. However people complained that updating the bootloader wasn't possible. I therefore suggested they go with a shim layer I termed the impedance matcher acting like an intermediate boot stage converting their (often unofficial and out-of-tree) ATAGs into proper DT nodes. Some people did exactly that and it works wonderfully for them. It also works wonderfully for kernel maintenance as the platform specific tweaks are kept out of the kernel tree. Still, that wasn't good enough for some cases as the move to DT regressed some platforms that just used to work before. Concatenating a DTB to zImage was tolerable but installing an additional shim layer was too much. Hence the ATAG-to-DT compat code in the decompressor. This was meant to smooth things around the transition to DT, etc. After all, those devices with non-replaceable bootloaders where shim layers are not possible should get out of commission eventually? We'd need to be careful about how we deal with the atags vs DT. I'd suggest (as above) that we have a tag which points at the DT in physical memory, and its size, and pre-scan the atag list for that. When we find it, we kick off the DT based stuff as we would normally do, and follow it with a parse of the atags. This would cause the atags to override whatever is in the DT, which afaics is the behaviour that we actually want. Maybe. However that would be yet another scheme for supporting legacy platforms with locked bootloaders. I really think we have enough of them already and I'd much prefer if we started _removing_ them not creating additional ones. The ATAG-to-DT code in the bootloader is still rather small and it works quite well, and it allows for configuring out ATAG support out of the kernel entirely. It should be sufficient for all the official (e.g. upstream) ATAGs already. If that's not good enough then people should consider the impedance matcher approach. We could augment that with code to update DT too so that we can export just the DT based information to kexec'd kernels. That should already be the case, no? Nicolas -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Tue 2015-01-27 13:50:22, Nicolas Pitre wrote: On Tue, 27 Jan 2015, Russell King - ARM Linux wrote: On Tue, Jan 27, 2015 at 10:16:24AM -0500, Nicolas Pitre wrote: On Tue, 27 Jan 2015, Pavel Machek wrote: (Note, that in 3.19 dts for n900 got too big, so we are actually triggering old bugs. That means that this is a regression fix, and should go in ASAP). It is queued here: http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8294/1 Irrespective of that patch, I commented on another thread (about adding the serial number to DT): | How about something a little more radical. | | Rather than trying to squeeze various ATAGs into DT, why don't we add a | standard ATAG to contain the DT and pass that through into the kernel. | This is IMHO how we _should_ have done the ATAG compatibility from the | start. | | That means we could get rid of most of the libfdt in the decompressor, | and instead resolve the differences in the kernel. That would allow us to get rid of all the FDT compatibility code in the decompressor, and when we encounter these special ATAGs, we can deal with them in the kernel instead of having to mess around with the DT. I'd also assume (although I haven't checked) that it would be much easier to add additional DT properties in the kernel environment, rather than in the rather restrictive decompressor environment. Well... I was initially against any ATAG-to-DT compatibility at all. IMHO the right solution is to update the bootloader. However people complained that updating the bootloader wasn't possible. I therefore suggested they go with a shim layer I termed the impedance matcher acting like an intermediate boot stage converting their (often unofficial and out-of-tree) ATAGs into proper DT nodes. Some people did exactly that and it works wonderfully for them. It also works wonderfully for kernel maintenance as the platform specific tweaks are kept out of the kernel tree. Still, that wasn't good enough for some cases as the move to DT regressed some platforms that just used to work before. Concatenating a DTB to zImage was tolerable but installing an additional shim layer was too much. Hence the ATAG-to-DT compat code in the decompressor. This was meant to smooth things around the transition to DT, etc. After all, those devices with non-replaceable bootloaders where shim layers are not possible should get out of commission eventually? N900 is still phone that is best-supported by the mainline, AFAICT. Yes, it is rather sad, but it means that no, it is probably not going out of commission anytime soon. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Tue, 27 Jan 2015, Pavel Machek wrote: I would say, problem is because omap3-n900 binary DT is too large I agree. OK if that's the case, then your patch makes sense to me. It also seems we can have the temporary stack be larger than the initial stack just for atags_to_fdt. The stack size isn't the issue, but rather its location. We need to position it away from the DT data. The DT size is known and we could use that, plus some room for the insertion of new data coming from the ATAG conversion. Something like the following would be a more robust solution: Tested-by: Pavel Machek pa...@ucw.cz (Note, that in 3.19 dts for n900 got too big, so we are actually triggering old bugs. That means that this is a regression fix, and should go in ASAP). It is queued here: http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8294/1 Nicolas -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Tue, Jan 27, 2015 at 01:50:22PM -0500, Nicolas Pitre wrote: Hence the ATAG-to-DT compat code in the decompressor. This was meant to smooth things around the transition to DT, etc. After all, those devices with non-replaceable bootloaders where shim layers are not possible should get out of commission eventually? Probably after 5 years there are still people using and hacking mainline Linux with N900 etc., and newer OMAPs (since there no useful devices) are long forgotten... A. -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Tuesday 27 January 2015 16:16:24 Nicolas Pitre wrote: On Tue, 27 Jan 2015, Pavel Machek wrote: I would say, problem is because omap3-n900 binary DT is too large I agree. OK if that's the case, then your patch makes sense to me. It also seems we can have the temporary stack be larger than the initial stack just for atags_to_fdt. The stack size isn't the issue, but rather its location. We need to position it away from the DT data. The DT size is known and we could use that, plus some room for the insertion of new data coming from the ATAG conversion. Something like the following would be a more robust solution: Tested-by: Pavel Machek pa...@ucw.cz (Note, that in 3.19 dts for n900 got too big, so we are actually triggering old bugs. That means that this is a regression fix, and should go in ASAP). It is queued here: http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id =8294/1 Nicolas I tested your patch and fdt_open_into() does not return error FDT_ERR_NOSPACE anymore. It is working. So you can add my Tested-by: Pali Rohár pali.ro...@gmail.com -- Pali Rohár pali.ro...@gmail.com signature.asc Description: This is a digitally signed message part.
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
* Nicolas Pitre nicolas.pi...@linaro.org [150127 07:19]: On Tue, 27 Jan 2015, Pavel Machek wrote: I would say, problem is because omap3-n900 binary DT is too large I agree. OK if that's the case, then your patch makes sense to me. It also seems we can have the temporary stack be larger than the initial stack just for atags_to_fdt. The stack size isn't the issue, but rather its location. We need to position it away from the DT data. The DT size is known and we could use that, plus some room for the insertion of new data coming from the ATAG conversion. Something like the following would be a more robust solution: Tested-by: Pavel Machek pa...@ucw.cz (Note, that in 3.19 dts for n900 got too big, so we are actually triggering old bugs. That means that this is a regression fix, and should go in ASAP). It is queued here: http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8294/1 Thanks for fixing that one! Regards, Tony -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Tue, Jan 27, 2015 at 10:16:24AM -0500, Nicolas Pitre wrote: On Tue, 27 Jan 2015, Pavel Machek wrote: (Note, that in 3.19 dts for n900 got too big, so we are actually triggering old bugs. That means that this is a regression fix, and should go in ASAP). It is queued here: http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8294/1 Irrespective of that patch, I commented on another thread (about adding the serial number to DT): | How about something a little more radical. | | Rather than trying to squeeze various ATAGs into DT, why don't we add a | standard ATAG to contain the DT and pass that through into the kernel. | This is IMHO how we _should_ have done the ATAG compatibility from the | start. | | That means we could get rid of most of the libfdt in the decompressor, | and instead resolve the differences in the kernel. That would allow us to get rid of all the FDT compatibility code in the decompressor, and when we encounter these special ATAGs, we can deal with them in the kernel instead of having to mess around with the DT. I'd also assume (although I haven't checked) that it would be much easier to add additional DT properties in the kernel environment, rather than in the rather restrictive decompressor environment. We'd need to be careful about how we deal with the atags vs DT. I'd suggest (as above) that we have a tag which points at the DT in physical memory, and its size, and pre-scan the atag list for that. When we find it, we kick off the DT based stuff as we would normally do, and follow it with a parse of the atags. This would cause the atags to override whatever is in the DT, which afaics is the behaviour that we actually want. We could augment that with code to update DT too so that we can export just the DT based information to kexec'd kernels. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
* Pali Rohár pali.ro...@gmail.com [150123 14:39]:
On Friday 23 January 2015 22:39:55 Pali Rohár wrote:
Hello,
when I boot zImage with appended DT n900 in qemu
fdt_open_into() function called from file
arch/arm/boot/compressed/atags_to_fdt.c (in function
atags_to_fdt) always returns -FDT_ERR_NOSPACE.
It means that all ATAGS (including cmdline arguments) passed
by bootloader are ignored.
On real n900 device I see that booted DT version also ignore
cmdline arguments from bootloader. I cannot debug decompress
code on real device, but I think it is same problem as in
qemu.
Looks like this quick patch is fixing above problem:
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 68be901..4a7d75b 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -268,7 +268,7 @@ restart: adr r0, LC0
* area. No GOT fixup has occurred yet, but none of the
* code we're about to call uses any global variable.
*/
- add sp, sp, #0x1
+ add sp, sp, #0x2
stmfd sp!, {r0-r3, ip, lr}
mov r0, r8
mov r1, r6
@@ -289,7 +289,7 @@ restart: adr r0, LC0
bleqatags_to_fdt
ldmfd sp!, {r0-r3, ip, lr}
- sub sp, sp, #0x1
+ sub sp, sp, #0x2
#endif
mov r8, r6 @ use the appended device tree
Nico, got any ideas about this one? This seems like a regression
somewhere..
Regards,
Tony
--
To unsubscribe from this list: send the line unsubscribe linux-omap in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Monday 26 January 2015 17:14:55 Tony Lindgren wrote:
* Pali Rohár pali.ro...@gmail.com [150123 14:39]:
On Friday 23 January 2015 22:39:55 Pali Rohár wrote:
Hello,
when I boot zImage with appended DT n900 in qemu
fdt_open_into() function called from file
arch/arm/boot/compressed/atags_to_fdt.c (in function
atags_to_fdt) always returns -FDT_ERR_NOSPACE.
It means that all ATAGS (including cmdline arguments)
passed by bootloader are ignored.
On real n900 device I see that booted DT version also
ignore cmdline arguments from bootloader. I cannot debug
decompress code on real device, but I think it is same
problem as in qemu.
Looks like this quick patch is fixing above problem:
diff --git a/arch/arm/boot/compressed/head.S
b/arch/arm/boot/compressed/head.S index 68be901..4a7d75b
100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -268,7 +268,7 @@ restart:adr r0, LC0
* area. No GOT fixup has occurred yet, but none of
the
* code we're about to call uses any global variable.
*/
- add sp, sp, #0x1
+ add sp, sp, #0x2
stmfd sp!, {r0-r3, ip, lr}
mov r0, r8
mov r1, r6
@@ -289,7 +289,7 @@ restart:adr r0, LC0
bleqatags_to_fdt
ldmfd sp!, {r0-r3, ip, lr}
- sub sp, sp, #0x1
+ sub sp, sp, #0x2
#endif
mov r8, r6 @ use the appended device tree
Nico, got any ideas about this one? This seems like a
regression somewhere..
Regards,
Tony
$ du -b arch/arm/boot/dts/omap3-n900.dtb
70212 arch/arm/boot/dts/omap3-n900.dtb
$ echo $((0x1))
65536
I would say, problem is because omap3-n900 binary DT is too large
--
Pali Rohár
pali.ro...@gmail.com
signature.asc
Description: This is a digitally signed message part.
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Mon, 26 Jan 2015, Tony Lindgren wrote:
* Pali Rohár pali.ro...@gmail.com [150126 08:26]:
On Monday 26 January 2015 17:14:55 Tony Lindgren wrote:
* Pali Rohár pali.ro...@gmail.com [150123 14:39]:
On Friday 23 January 2015 22:39:55 Pali Rohár wrote:
Hello,
when I boot zImage with appended DT n900 in qemu
fdt_open_into() function called from file
arch/arm/boot/compressed/atags_to_fdt.c (in function
atags_to_fdt) always returns -FDT_ERR_NOSPACE.
It means that all ATAGS (including cmdline arguments)
passed by bootloader are ignored.
On real n900 device I see that booted DT version also
ignore cmdline arguments from bootloader. I cannot debug
decompress code on real device, but I think it is same
problem as in qemu.
Looks like this quick patch is fixing above problem:
diff --git a/arch/arm/boot/compressed/head.S
b/arch/arm/boot/compressed/head.S index 68be901..4a7d75b
100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -268,7 +268,7 @@ restart:adr r0, LC0
* area. No GOT fixup has occurred yet, but none of
the
* code we're about to call uses any global variable.
*/
- add sp, sp, #0x1
+ add sp, sp, #0x2
stmfd sp!, {r0-r3, ip, lr}
mov r0, r8
mov r1, r6
@@ -289,7 +289,7 @@ restart:adr r0, LC0
bleqatags_to_fdt
ldmfd sp!, {r0-r3, ip, lr}
- sub sp, sp, #0x1
+ sub sp, sp, #0x2
#endif
mov r8, r6 @ use the appended
device tree
Nico, got any ideas about this one? This seems like a
regression somewhere..
Regards,
Tony
$ du -b arch/arm/boot/dts/omap3-n900.dtb
70212 arch/arm/boot/dts/omap3-n900.dtb
$ echo $((0x1))
65536
I would say, problem is because omap3-n900 binary DT is too large
I agree.
OK if that's the case, then your patch makes sense to me. It also
seems we can have the temporary stack be larger than the initial
stack just for atags_to_fdt.
The stack size isn't the issue, but rather its location. We need to
position it away from the DT data. The DT size is known and we could
use that, plus some room for the insertion of new data coming from the
ATAG conversion.
Something like the following would be a more robust solution:
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 68be901759..89718de9dd 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -263,16 +263,37 @@ restart: adr r0, LC0
* OK... Let's do some funky business here.
* If we do have a DTB appended to zImage, and we do have
* an ATAG list around, we want the later to be translated
-* and folded into the former here. To be on the safe side,
-* let's temporarily move the stack away into the malloc
-* area. No GOT fixup has occurred yet, but none of the
-* code we're about to call uses any global variable.
+* and folded into the former here. No GOT fixup has occurred
+* yet, but none of the code we're about to call uses any
+* global variable.
*/
- add sp, sp, #0x1
+
+ /* Get the initial DTB size */
+ ldr r5, [r6, #4]
+#ifndef __ARMEB__
+ /* convert to little endian */
+ eor r1, r5, r5, ror #16
+ bic r1, r1, #0x00ff
+ mov r5, r5, ror #8
+ eor r5, r5, r1, lsr #8
+#endif
+ /* 50% DTB growth should be good enough */
+ add r5, r5, r5, lsr #1
+ /* preserve 64-bit alignment */
+ add r5, r5, #7
+ bic r5, r5, #7
+ /* clamp to 32KB min and 1MB max */
+ movsr1, r5, lsr #15
+ moveq r5, #(1 15)
+ movsr1, r5, lsr #20
+ movne r5, #(1 20)
+
+ /* Temporarily relocate the stack past the DTB work space */
+ add sp, sp, r5
stmfd sp!, {r0-r3, ip, lr}
mov r0, r8
mov r1, r6
- sub r2, sp, r6
+ mov r2, r5
bl atags_to_fdt
/*
@@ -285,11 +306,11 @@ restart: adr r0, LC0
bic r0, r0, #1
add r0, r0, #0x100
mov r1, r6
- sub r2, sp, r6
+
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
* Pali Rohár pali.ro...@gmail.com [150126 08:26]:
On Monday 26 January 2015 17:14:55 Tony Lindgren wrote:
* Pali Rohár pali.ro...@gmail.com [150123 14:39]:
On Friday 23 January 2015 22:39:55 Pali Rohár wrote:
Hello,
when I boot zImage with appended DT n900 in qemu
fdt_open_into() function called from file
arch/arm/boot/compressed/atags_to_fdt.c (in function
atags_to_fdt) always returns -FDT_ERR_NOSPACE.
It means that all ATAGS (including cmdline arguments)
passed by bootloader are ignored.
On real n900 device I see that booted DT version also
ignore cmdline arguments from bootloader. I cannot debug
decompress code on real device, but I think it is same
problem as in qemu.
Looks like this quick patch is fixing above problem:
diff --git a/arch/arm/boot/compressed/head.S
b/arch/arm/boot/compressed/head.S index 68be901..4a7d75b
100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -268,7 +268,7 @@ restart: adr r0, LC0
* area. No GOT fixup has occurred yet, but none of
the
* code we're about to call uses any global variable.
*/
- add sp, sp, #0x1
+ add sp, sp, #0x2
stmfd sp!, {r0-r3, ip, lr}
mov r0, r8
mov r1, r6
@@ -289,7 +289,7 @@ restart: adr r0, LC0
bleqatags_to_fdt
ldmfd sp!, {r0-r3, ip, lr}
- sub sp, sp, #0x1
+ sub sp, sp, #0x2
#endif
mov r8, r6 @ use the appended device tree
Nico, got any ideas about this one? This seems like a
regression somewhere..
Regards,
Tony
$ du -b arch/arm/boot/dts/omap3-n900.dtb
70212 arch/arm/boot/dts/omap3-n900.dtb
$ echo $((0x1))
65536
I would say, problem is because omap3-n900 binary DT is too large
OK if that's the case, then your patch makes sense to me. It also
seems we can have the temporary stack be larger than the initial
stack just for atags_to_fdt.
Regards,
Tony
--
To unsubscribe from this list: send the line unsubscribe linux-omap in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
Hi! $ du -b arch/arm/boot/dts/omap3-n900.dtb 70212 arch/arm/boot/dts/omap3-n900.dtb $ echo $((0x1)) 65536 I would say, problem is because omap3-n900 binary DT is too large I agree. OK if that's the case, then your patch makes sense to me. It also seems we can have the temporary stack be larger than the initial stack just for atags_to_fdt. The stack size isn't the issue, but rather its location. We need to position it away from the DT data. The DT size is known and we could use that, plus some room for the insertion of new data coming from the ATAG conversion. Something like the following would be a more robust solution: diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 68be901759..89718de9dd 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -263,16 +263,37 @@ restart:adr r0, LC0 * OK... Let's do some funky business here. * If we do have a DTB appended to zImage, and we do have * an ATAG list around, we want the later to be translated - * and folded into the former here. To be on the safe side, - * let's temporarily move the stack away into the malloc - * area. No GOT fixup has occurred yet, but none of the - * code we're about to call uses any global variable. + * and folded into the former here. No GOT fixup has occurred + * yet, but none of the code we're about to call uses any + * global variable. */ - add sp, sp, #0x1 + + /* Get the initial DTB size */ + ldr r5, [r6, #4] +#ifndef __ARMEB__ + /* convert to little endian */ + eor r1, r5, r5, ror #16 + bic r1, r1, #0x00ff + mov r5, r5, ror #8 + eor r5, r5, r1, lsr #8 +#endif + /* 50% DTB growth should be good enough */ + add r5, r5, r5, lsr #1 + /* preserve 64-bit alignment */ + add r5, r5, #7 + bic r5, r5, #7 + /* clamp to 32KB min and 1MB max */ + movsr1, r5, lsr #15 + moveq r5, #(1 15) + movsr1, r5, lsr #20 + movne r5, #(1 20) Dunno. Would it be easier/simpler to just use 1MB, always? Do we support machines with 16MB RAM? Best regards, -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Mon, 26 Jan 2015, Pavel Machek wrote: Hi! $ du -b arch/arm/boot/dts/omap3-n900.dtb 70212 arch/arm/boot/dts/omap3-n900.dtb $ echo $((0x1)) 65536 I would say, problem is because omap3-n900 binary DT is too large I agree. OK if that's the case, then your patch makes sense to me. It also seems we can have the temporary stack be larger than the initial stack just for atags_to_fdt. The stack size isn't the issue, but rather its location. We need to position it away from the DT data. The DT size is known and we could use that, plus some room for the insertion of new data coming from the ATAG conversion. Something like the following would be a more robust solution: diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 68be901759..89718de9dd 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -263,16 +263,37 @@ restart: adr r0, LC0 * OK... Let's do some funky business here. * If we do have a DTB appended to zImage, and we do have * an ATAG list around, we want the later to be translated -* and folded into the former here. To be on the safe side, -* let's temporarily move the stack away into the malloc -* area. No GOT fixup has occurred yet, but none of the -* code we're about to call uses any global variable. +* and folded into the former here. No GOT fixup has occurred +* yet, but none of the code we're about to call uses any +* global variable. */ - add sp, sp, #0x1 + + /* Get the initial DTB size */ + ldr r5, [r6, #4] +#ifndef __ARMEB__ + /* convert to little endian */ + eor r1, r5, r5, ror #16 + bic r1, r1, #0x00ff + mov r5, r5, ror #8 + eor r5, r5, r1, lsr #8 +#endif + /* 50% DTB growth should be good enough */ + add r5, r5, r5, lsr #1 + /* preserve 64-bit alignment */ + add r5, r5, #7 + bic r5, r5, #7 + /* clamp to 32KB min and 1MB max */ + movsr1, r5, lsr #15 + moveq r5, #(1 15) + movsr1, r5, lsr #20 + movne r5, #(1 20) Dunno. Would it be easier/simpler to just use 1MB, always? Do we support machines with 16MB RAM? If people are used to put other things relatively close to the kernel image like, say, some initrd image, then I'd prefer to be more conservative and avoid spreading out too much. Nicolas -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Saturday 24 January 2015 00:48:55 Pavel Machek wrote:
On Fri 2015-01-23 23:36:36, Pali Rohár wrote:
On Friday 23 January 2015 22:39:55 Pali Rohár wrote:
Hello,
when I boot zImage with appended DT n900 in qemu
fdt_open_into() function called from file
arch/arm/boot/compressed/atags_to_fdt.c (in function
atags_to_fdt) always returns -FDT_ERR_NOSPACE.
It means that all ATAGS (including cmdline arguments)
passed by bootloader are ignored.
On real n900 device I see that booted DT version also
ignore cmdline arguments from bootloader. I cannot debug
decompress code on real device, but I think it is same
problem as in qemu.
Looks like this quick patch is fixing above problem:
So... something overruns stack, and bigger stack fixes it...?
Pavel
Yes, it looks like that DTB file for n900 is too big and
atags_to_fdt.c cannot append anything to it (kernel cmdline)...
diff --git a/arch/arm/boot/compressed/head.S
b/arch/arm/boot/compressed/head.S index 68be901..4a7d75b
100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -268,7 +268,7 @@ restart:adr r0, LC0
* area. No GOT fixup has occurred yet, but none of
the
* code we're about to call uses any global variable.
*/
- add sp, sp, #0x1
+ add sp, sp, #0x2
stmfd sp!, {r0-r3, ip, lr}
mov r0, r8
mov r1, r6
@@ -289,7 +289,7 @@ restart:adr r0, LC0
bleqatags_to_fdt
ldmfd sp!, {r0-r3, ip, lr}
- sub sp, sp, #0x1
+ sub sp, sp, #0x2
#endif
mov r8, r6 @ use the appended device tree
--
Pali Rohár
pali.ro...@gmail.com
signature.asc
Description: This is a digitally signed message part.
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Friday 23 January 2015 22:39:55 Pali Rohár wrote:
Hello,
when I boot zImage with appended DT n900 in qemu
fdt_open_into() function called from file
arch/arm/boot/compressed/atags_to_fdt.c (in function
atags_to_fdt) always returns -FDT_ERR_NOSPACE.
It means that all ATAGS (including cmdline arguments) passed
by bootloader are ignored.
On real n900 device I see that booted DT version also ignore
cmdline arguments from bootloader. I cannot debug decompress
code on real device, but I think it is same problem as in
qemu.
Looks like this quick patch is fixing above problem:
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 68be901..4a7d75b 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -268,7 +268,7 @@ restart:adr r0, LC0
* area. No GOT fixup has occurred yet, but none of the
* code we're about to call uses any global variable.
*/
- add sp, sp, #0x1
+ add sp, sp, #0x2
stmfd sp!, {r0-r3, ip, lr}
mov r0, r8
mov r1, r6
@@ -289,7 +289,7 @@ restart:adr r0, LC0
bleqatags_to_fdt
ldmfd sp!, {r0-r3, ip, lr}
- sub sp, sp, #0x1
+ sub sp, sp, #0x2
#endif
mov r8, r6 @ use the appended device tree
--
Pali Rohár
pali.ro...@gmail.com
signature.asc
Description: This is a digitally signed message part.
N900 v3.19-rc5 arm atags_to_fdt.c is broken
Hello, when I boot zImage with appended DT n900 in qemu fdt_open_into() function called from file arch/arm/boot/compressed/atags_to_fdt.c (in function atags_to_fdt) always returns -FDT_ERR_NOSPACE. It means that all ATAGS (including cmdline arguments) passed by bootloader are ignored. On real n900 device I see that booted DT version also ignore cmdline arguments from bootloader. I cannot debug decompress code on real device, but I think it is same problem as in qemu. -- Pali Rohár pali.ro...@gmail.com signature.asc Description: This is a digitally signed message part.
Re: N900 v3.19-rc5 arm atags_to_fdt.c is broken
On Fri 2015-01-23 23:36:36, Pali Rohár wrote:
On Friday 23 January 2015 22:39:55 Pali Rohár wrote:
Hello,
when I boot zImage with appended DT n900 in qemu
fdt_open_into() function called from file
arch/arm/boot/compressed/atags_to_fdt.c (in function
atags_to_fdt) always returns -FDT_ERR_NOSPACE.
It means that all ATAGS (including cmdline arguments) passed
by bootloader are ignored.
On real n900 device I see that booted DT version also ignore
cmdline arguments from bootloader. I cannot debug decompress
code on real device, but I think it is same problem as in
qemu.
Looks like this quick patch is fixing above problem:
So... something overruns stack, and bigger stack fixes it...?
Pavel
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 68be901..4a7d75b 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -268,7 +268,7 @@ restart: adr r0, LC0
* area. No GOT fixup has occurred yet, but none of the
* code we're about to call uses any global variable.
*/
- add sp, sp, #0x1
+ add sp, sp, #0x2
stmfd sp!, {r0-r3, ip, lr}
mov r0, r8
mov r1, r6
@@ -289,7 +289,7 @@ restart: adr r0, LC0
bleqatags_to_fdt
ldmfd sp!, {r0-r3, ip, lr}
- sub sp, sp, #0x1
+ sub sp, sp, #0x2
#endif
mov r8, r6 @ use the appended device tree
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures)
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line unsubscribe linux-omap in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
