<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:dt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=KO link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Hello all,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>To make a minimal kernel size (with almost no driver), I copied a .config that was used for building kernel for sparc machine using linux 3.3 several years ago to current linux 5.4.21 version build tree.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>(That .config was for kernel with interrupt controller, timer and uart so a very basic scheduling and shell is possible.)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Then I ran <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Yes “” | make ARCH=arm64 CROSS_COMPILE=aarch64-none-elf- oldconfig<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>This copies the configs and sets all the new config settings with default values. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>(see https://serverfault.com/questions/116299/automatically-answer-defaults-when-doing-make-oldconfig-on-a-kernel-tree)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Now I can see the start_kernel function runs to the end and it’s running inside the cpu_idle function. but I don’t see the first scrolling message below that I normally should see.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>[ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd083]<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>I tried adding several CONFIG variables using menuconfig but it’s still the same.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> (CONFIG_SERIAL_AMBA_PL010, CONFIG_SERIAL_AMBA_PL010_CONSOLE, CONFIG_SERIAL_CORE, CONFIG_SERIAL_CORE_CONSOLE were already automatically set. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>And later I tried adding CONFIG_CPU_IDLE, CONFIG_CPU_IDLE_GOV_LADDR, CONFIG_ACPI and other ACPI related things, CONFIG_PCI_ECAM, CONFIG_PNP, CONFIG_PNP_DEBUG_MESSAGES, .. )<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>And the qemu command is like this.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>${QEMU_DIR}/qemu-system-aarch64 -M ${QMACHINE} -cpu cortex-a72 -kernel ${LINUX_DIR}/arch/arm64/boot/Image -initrd ${BUSYBOX_DIR}/initramfs.cpio.gz --append "root=/dev/ram init=/init nokaslr earlycon ip=dhcp" -m 2048M -nographic -netdev user,id=n1 -device e1000,netdev=n1<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Has anyone any idea what I can add in the config or try? (with original .config, the kernel boots ok to the bash in initramfs)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Any suggestion will be appreciated.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Thank you,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Kind regards,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Chan Kim<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></body></html>