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ClangBuiltLinux / boot-utils

Collection of files for booting Linux kernels
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boot-qemu.sh: Use different CPU for arm64 with new QEMU + old kernel #61

Closed nathanchance closed 2 years ago

nathanchance commented 2 years ago

After FEAT_LPA was implemented in QEMU's TCG, kernels older than 4.19, namely 4.9 and 4.14, fail to boot. We already have a workaround for FEAT_LPA2 not working with kernels older than 5.12, which is known. Reporting this to QEMU upstream resulted in the recommendation to use one of the ARMv8.0 CPUs for these older kernels. Use 'cortex-a72' for booting anything older than 4.19 with QEMU 6.2.50 (master) and newer.

Link: https://gitlab.com/qemu-project/qemu/-/issues/964

nickdesaulniers commented 2 years ago

From that thread, it sounds like there's perhaps a missing backport we should take into stable instead? https://gitlab.com/qemu-project/qemu/-/issues/964#note_903279226

nathanchance commented 2 years ago

Maybe, I'll see.

nathanchance commented 2 years ago

I've updated the kernel check and commit message based on my analysis at https://gitlab.com/qemu-project/qemu/-/issues/964#note_903403849.

nathanchance commented 2 years ago

Thanks for double checking my analysis as always!