15451 2024-03-21 08:52:18 +0000 llvm: objcopy error when using llvm to build kernel 2025-11-14 14:24:39 +0000 1 1 7 Build System, Metadata & Runtime OE-Core kernel 4.0.20 x86 Multiple RESOLVED FIXED Medium enhancement 4.0.32 1 lxy204899 unassigned hemanth.250302 lxy204899 randy.macleod steve sundeep.kokkonda --- --- No (bug/feature does not impact docs) oldest_to_newest 98547 0 lxy204899 2024-03-21 08:52:18 +0000 When using the llvm to compile kernel by meta-clang, the strip tool from gcc is used always. It is advisable to use ${HOST_PREFIX}llvm-objcopy instead of ${HOST_PREFIX}objcopy in kernel-module-split.bbclass if llvm condition. ``` ### kernel-module-split.bbclass line 65 cmd = "%sobjcopy -j .modinfo -O binary %s %s" % (d.getVar("HOST_PREFIX") or "", tmpkofile, tmpfile) else: cmd = "%sobjcopy -j .modinfo -O binary %s %s" % (d.getVar("HOST_PREFIX") or "", file, tmpfile) subprocess.check_call(cmd, shell=True) ``` 98561 1 randy.macleod 2024-03-21 14:51:34 +0000 Can you send a patch to change the recipe to use the OBJCOPY variable defined in bitbake.conf. 98576 2 5034 lxy204899 2024-03-22 02:31:20 +0000 Created attachment 5034 enhance objcopy command call for kernel compilation with llvm 98577 3 lxy204899 2024-03-22 02:33:01 +0000 Okay, it's a good idea. I have submitted a patch. 98675 4 lxy204899 2024-03-29 07:03:26 +0000 Recently I discovered many similar issues without using the 'llvm' prefix. I would like to ask, how has the community's support for llvm been recently? 98676 5 lxy204899 2024-03-29 07:08:37 +0000 When searching for `${HOST_PREFIX}` and `${HOST_PREFIX}`, you will find a lot of similar calls. 100073 6 randy.macleod 2024-10-31 15:06:25 +0000 move to unassigned. feel free to take back if you have time. 103184 7 randy.macleod 2025-11-04 19:58:39 +0000 Sundeep, Can we have someone test this on master ONLY? With the changes that happened in moving clang to oe-core, perhaps the problem has been fixed. We (YP) have no plan to backport a fix for 4.0.xx since we don't really even now support building the kernel with clang IIRC. 103296 8 hemanth.250302 2025-11-14 06:30:35 +0000 Hi Randy, This issue is no longer seen in poky-master, as the patch/fix for kernel-module-split.bbclass is already present. The kernel build now correctly uses ${KERNEL_OBJCOPY} / ${OBJCOPY}, which resolve to llvm-objcopy when building with Clang, instead of the hard-coded objcopy. 103300 9 randy.macleod 2025-11-14 14:22:52 +0000 Resolved as per Hemanth's explanation. Thanks everyone. 103301 10 randy.macleod 2025-11-14 14:24:39 +0000 This was reported against 4.0 but I think a backport is out of scope since so much has changed with the merge of clang to oe-core. Sorry. 5034 2024-03-22 02:31:20 +0000 2024-03-22 02:31:20 +0000 enhance objcopy command call for kernel compilation with llvm 0001-kernel-module-split.bbclass-enhance-objcopy-command-.patch text/plain 1798 lxy204899 RnJvbSA4MzA2YmRhM2M4Yjk3MGQwZmI4N2RiZDNiNTMwM2MyZDBkMWY3MzRiIE1vbiBTZXAgMTcg MDA6MDA6MDAgMjAwMQpGcm9tOiBsaXhpYW95b25nIDxsaXhpYW95b25nMTlAaHVhd2VpLmNvbT4K RGF0ZTogRnJpLCAyMiBNYXIgMjAyNCAwOTo1NzoxNSArMDgwMApTdWJqZWN0OiBbUEFUQ0hdIGtl cm5lbC1tb2R1bGUtc3BsaXQuYmJjbGFzczogZW5oYW5jZSBvYmpjb3B5IGNvbW1hbmQgY2FsbCBm b3IKIGtlcm5lbCBjb21waWxhdGlvbiB3aXRoIGxsdm0KClVzaW5nIG1ldGEtY2xhbmcgZm9yIGxs dm0ga2VybmVsIGNvbXBpbGF0aW9uIHByZXZpb3VzbHkgZGVmYXVsdGVkIHRvIHRoZSBnY2Mgb2Jq Y29weSB0b29sLgpUbyBpbXByb3ZlIGZsZXhpYmlsaXR5IGFuZCBjb21wYXRpYmlsaXR5LCAkT0JK Q09QWSBpcyBwcmVmZXJyZWQgb3ZlciAkSE9TVF9QUkVGSVhvYmpjb3B5CmluIHRoZSBrZXJuZWwt bW9kdWxlLXNwbGl0LmJiY2xhc3MuCgpXaXRoICRPQkpDT1BZIGFscmVhZHkgZGVmaW5lZCBpbiBi aXRiYWtlLmNvbmYsIHRoZSBlbXB0eSBjb25kaXRpb24gaGFzIGJlZW4gcmVtb3ZlZCwKc2ltcGxp ZnlpbmcgdGhlIGludm9jYXRpb24gcHJvY2Vzcy4KClNpZ25lZC1vZmYtYnk6IGxpeGlhb3lvbmcg PGxpeGlhb3lvbmcxOUBodWF3ZWkuY29tPgotLS0KIG1ldGEvY2xhc3Nlcy9rZXJuZWwtbW9kdWxl LXNwbGl0LmJiY2xhc3MgfCA0ICsrLS0KIDEgZmlsZSBjaGFuZ2VkLCAyIGluc2VydGlvbnMoKyks IDIgZGVsZXRpb25zKC0pCgpkaWZmIC0tZ2l0IGEvbWV0YS9jbGFzc2VzL2tlcm5lbC1tb2R1bGUt c3BsaXQuYmJjbGFzcyBiL21ldGEvY2xhc3Nlcy9rZXJuZWwtbW9kdWxlLXNwbGl0LmJiY2xhc3MK aW5kZXggYTI5YzI5NDgxMC4uMjgzNDliYWY3OCAxMDA2NDQKLS0tIGEvbWV0YS9jbGFzc2VzL2tl cm5lbC1tb2R1bGUtc3BsaXQuYmJjbGFzcworKysgYi9tZXRhL2NsYXNzZXMva2VybmVsLW1vZHVs ZS1zcGxpdC5iYmNsYXNzCkBAIC02Miw5ICs2Miw5IEBAIHB5dGhvbiBzcGxpdF9rZXJuZWxfbW9k dWxlX3BhY2thZ2VzICgpIHsKICAgICAgICAgICAgIGVsc2U6CiAgICAgICAgICAgICAgICAgbXNn ID0gIkNhbm5vdCBkZWNvbXByZXNzICclcyciICUgZmlsZQogICAgICAgICAgICAgICAgIHJhaXNl IG1zZwotICAgICAgICAgICAgY21kID0gIiVzb2JqY29weSAtaiAubW9kaW5mbyAtTyBiaW5hcnkg JXMgJXMiICUgKGQuZ2V0VmFyKCJIT1NUX1BSRUZJWCIpIG9yICIiLCB0bXBrb2ZpbGUsIHRtcGZp bGUpCisgICAgICAgICAgICBjbWQgPSAiJXMgLWogLm1vZGluZm8gLU8gYmluYXJ5ICVzICVzIiAl IChkLmdldFZhcigiT0JKQ09QWSIpLCB0bXBrb2ZpbGUsIHRtcGZpbGUpCiAgICAgICAgIGVsc2U6 Ci0gICAgICAgICAgICBjbWQgPSAiJXNvYmpjb3B5IC1qIC5tb2RpbmZvIC1PIGJpbmFyeSAlcyAl cyIgJSAoZC5nZXRWYXIoIkhPU1RfUFJFRklYIikgb3IgIiIsIGZpbGUsIHRtcGZpbGUpCisgICAg ICAgICAgICBjbWQgPSAiJXMgLWogLm1vZGluZm8gLU8gYmluYXJ5ICVzICVzIiAlIChkLmdldFZh cigiT0JKQ09QWSIpLCBmaWxlLCB0bXBmaWxlKQogICAgICAgICBzdWJwcm9jZXNzLmNoZWNrX2Nh bGwoY21kLCBzaGVsbD1UcnVlKQogICAgICAgICAjIGVycm9ycz0ncmVwbGFjZSc6IFNvbWUgb2xk IGtlcm5lbCB2ZXJzaW9ucyBjb250YWluIGludmFsaWQgdXRmLTggY2hhcmFjdGVycyBpbiBtb2Qg ZGVzY3JpcHRpb25zIChsaWtlIDB4ZjYsICfDticpCiAgICAgICAgIGYgPSBvcGVuKHRtcGZpbGUs IGVycm9ycz0ncmVwbGFjZScpCi0tIAoyLjMyLjAKCg==