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Merge GRUB cmdline instead of overwriting it (closes #19) - #30
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tune_kernel replaced GRUB_CMDLINE_LINUX_DEFAULT wholesale, dropping any other kernel parameters the user/distro had set (a boot-safety risk). Add a pure grub_merge_cmdline helper that preserves every existing param and replaces only the HugePage/MSR params we manage (hugepagesz/hugepages/default_hugepagesz/ msr.allow_writes), and use it in tune_kernel. Idempotent: re-runs strip the old managed params and re-add the current ones, so a stable config detects "already configured" and makes no change. Tests: unit tests for grub_merge_cmdline (preserve/replace/idempotent) and an E2E assertion that "quiet splash" survives the HugePage configuration. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Problem (#19 — boot-safety)
tune_kernelconfigured persistent HugePages by replacing the whole line:sed -i 's|^GRUB_CMDLINE_LINUX_DEFAULT=.*|GRUB_CMDLINE_LINUX_DEFAULT="$NEW_PARAMS"|'$NEW_PARAMSisproposed-grub.sh's full string (quiet splash <hugepages/msr params>), so any other kernel parameters the user or distro had set were silently dropped — e.g.nomodeset,intel_iommu=on,amd_iommu=on,console=, root-fs flags. On the wrong box that's a failed/headless boot.Fix
A pure, testable
grub_merge_cmdlinehelper merges in only the params we own and preserves everything else:hugepagesz=*,hugepages=*,default_hugepagesz=*,msr.allow_writes=*).bak)tune_kernelnow reads the current cmdline, computes the merge, and only rewrites when it actually changes (still backing up to.bakfirst).Tests
grub_merge_cmdlinepreservesquiet/customnomodeset, adds the HugePage/MSR params, is idempotent, and replaces (not accumulates) stale managed params.quiet splashis still present in/etc/default/grubafter HugePage configuration (native Linux + Docker).No Pithead/XMRig surface (host-local boot config).
make testgreen; closes #19.🤖 Generated with Claude Code