meta-synopsys: ARCv3 support #8
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Upstream libffi does not yet support ARCv3. Meanwhile libffi support for 64-bit ARCv3 architecture is available in Synopsys libffi fork on github. This commit adds libffi bbappend to enable support for arc64. Signed-off-by: Sergey Matyukevich <[email protected]>
ARCv3 32-bit CPU does not have support for 64-bit atomic operations. Emulate missing atomic contstructs via libatomic. Signed-off-by: Sergey Matyukevich <[email protected]>
Upstream Linux kernel does not yet support ARCv3. Add recipe for Synopsys kernel fork on github which provides initial ARCv3 support for both 32-bit and 64-bit architecture flavors. Signed-off-by: Sergey Matyukevich <[email protected]>
Add perl-cross patch adding support for ARCv3. Signed-off-by: Sergey Matyukevich <[email protected]>
Update ARC gcc version to arc-2021.03 release. New version adds support for ARCv3. Signed-off-by: Sergey Matyukevich <[email protected]>
Update ARC binutils version to arc-2021.03 release. New version adds support for ARCv3. Signed-off-by: Sergey Matyukevich <[email protected]>
Upstream glibc does not yet support ARCv3. Add recipes for Synopsys glibc fork that provides support for the new architecture. Signed-off-by: Sergey Matyukevich <[email protected]>
Add tune features for ARCv3. Add two ARCv3 machines: HS5x and HS6x. Signed-off-by: Sergey Matyukevich <[email protected]>
Add custom minimalistic distro suitable for ARCv3 devices including both HS5x and HS6x. This distro provides core-image-minimal image with busybox mdev as a device and inirt manager. The primary purpose of this distro is to generate small kernel ramdisks images suitable for running ARC kernels using nSIM and QEMU emulators. Signed-off-by: Sergey Matyukevich <[email protected]>
Updated layer is compatible with Yocto v4.0 Kirkstone release. Signed-off-by: Sergey Matyukevich <[email protected]>
| @@ -8,6 +8,6 @@ BBFILE_COLLECTIONS += "synopsys-layer" | |||
| BBFILE_PATTERN_synopsys-layer = "^${LAYERDIR}/" | |||
| BBFILE_PRIORITY_synopsys-layer = "6" | |||
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| LAYERSERIES_COMPAT_synopsys-layer = " honister" | |||
| LAYERSERIES_COMPAT_synopsys-layer = " kirkstone" | |||
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Cannot we just add kirkstone along with honister? I.e. is there something which makes our layer incompatible with honister?
For the record, kirkstone is going to be the next LTS - so it's good to rely on it looking forward.
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| DISTRO_NAME = "Synopsys minimal ramdisk" | |||
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I'm wondering how much smaller is that image compared to core-image-minimal?
Or there're other benefits compared to aforementioned more standard "distro"?
| VIRTUAL-RUNTIME_init_manager = "busybox" | ||
| VIRTUAL-RUNTIME_base-utils = "busybox" | ||
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| PREFERRED_PROVIDER_virtual/kernel = "linux-arc64-dev" |
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BTW by the time of this change Linux for ARCv3 is not yet available.
So that might be another reason to not mess with our own distro ;)
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| PREFERRED_PROVIDER_virtual/kernel = "linux-arc64-dev" | ||
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| GCCVERSION = "arc" |
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I guess that all might go into conf/machine/hapshs{5|6}x.conf.
Moreover I'd do that more future proof with ?= so that when ARCv3 ports are merged upstream we may override that in the local.conf.
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| TUNE_ARCH = "${@bb.utils.contains('TUNE_FEATURES', 'hs58', 'arc32', 'arc64', d)}" | |||
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Why adding hs58 in TUNE_ARCH? Readme sys "TUNE_ARCH - The GNU canonical arch for a specific architecture". And so it looks like more appropriate would be only arc32 & arc64.
| TUNE_PKGARCH = "${TUNE_PKGARCH_tune-${DEFAULTTUNE}}" | ||
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| TUNEVALID[hs58] = "Enable ARCv3 64-bit" | ||
| TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'hs58', ' -mcpu=hs5x', '', d)}" |
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This is incorrect technically as we do have 2 separate flavors of -mcpu (hs58 & hs5x) and they are not the same: on top of hs5x, hs58 has advanced mpy9 SIMD instructions and double load/store instructions.
I.e. we need to have both tunes: hs5x & hs58. Moreover if to be more flexible and to some extent more compatible we may do what's done for ARCv2: have hs5x as a base and make hs58 tune as a superset with some more options (namely -mll64 & -msimd).
| TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'hs58', ' -mcpu=hs5x', '', d)}" | ||
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| TUNEVALID[hs68] = "Enable ARCv3 64-bit core" | ||
| TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'hs68', ' -mcpu=hs6x', '', d)}" |
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Similar goes here: hs68 is hs6x + -msimd + -m128.
| TUNEVALID[ll128] = "Enable 128-bit load/store operations" | ||
| TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'll128', ' -m128', ' -mno-128', d)}" | ||
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| TUNEVALID[div_rem] = "Enable simple divider" |
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Not sure really if we want to deal with so powerful new processors w/o HW division - it will compromise their purpose as a high-performance application processors then, no? :)
Summary
This PR implements the following updates for Synopsys Yocto layer:
ARCv3 changes
Here are the lists of ARCv3 specific changes required for OE layers.
openembedded-core
ARCv3 support is implemented in patch. This patch has not yet been upstreamed.
meta-synopsys
This PR includes the following ARCv3 specific changes:
Status
HS6x
Build commands for HS6x machine using snps-arc64-minimal distro:
Successful build and boot using nSIM.
HS5x
Build command for HS5x machine using snps-arc64-minimal distro:
Currently build fails on libffi which lacks support for ARCv3 32-bit processors. However libffi is not actually needed for minimal boot image. So quick non-functional libffi fix (replace pop_s/push_s by pop/push instructions) allows build to successfully complete. The resulting image boots fine using nSIM.
Notes
This PR will remain in WIP state until ARCv3 triplets are finalized.