Currently, the UART early address is set indirectly with the --vmm option and there are only two possible values: if the VMM is qemu (the default), then the UART address is set to 0x09000000; if the VMM is kvmtool, then the UART address is set to 0x3f8.
There several efforts under way to change the kvmtool UART address, and kvm-unit-tests so far hasn't had mechanism to let the user set a specific address, which means that the early UART won't be available. This situation will only become worse as kvm-unit-tests gains support to run as an EFI app, as each platform will have their own UART type and address. To address both issues, a new configure option is added, --earlycon. The syntax and semantics are identical to the kernel parameter with the same name. Specifying this option will overwrite the UART address set by --vmm. At the moment, the UART type and register width parameters are ignored since both qemu's and kvmtool's UART emulation use the same offset for the TX register and no other registers are used by kvm-unit-tests, but the parameters will become relevant once EFI support is added. Signed-off-by: Alexandru Elisei <[email protected]> --- The kvmtool patches I was referring to are the patches to unify ioport and MMIO emulation [1] and to allow the user to specify a custom memory layout for the VM [2] (these patches are very old, but I plan to revive them after the ioport and MMIO unification series are merged). [1] https://lore.kernel.org/kvm/[email protected]/T/#t [2] https://lore.kernel.org/kvm/[email protected]/ configure | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/configure b/configure index cdcd34e94030..d94b92255088 100755 --- a/configure +++ b/configure @@ -26,6 +26,7 @@ errata_force=0 erratatxt="$srcdir/errata.txt" host_key_document= page_size= +earlycon= usage() { cat <<-EOF @@ -54,6 +55,17 @@ usage() { --page-size=PAGE_SIZE Specify the page size (translation granule) (4k, 16k or 64k, default is 64k, arm64 only) + --earlycon=EARLYCON + Specify the UART name, type and address (optional, arm and + arm64 only). The specified address will overwrite the UART + address set by the --vmm option. EARLYCON can be on of (case + sensitive): + uart[8250],mmio,ADDR + Specify an 8250 compatible UART at address ADDR. Supported + register stride is 8 bit only. + pl011,mmio,ADDR + Specify a PL011 compatible UART at address ADDR. Supported + register stride is 8 bit only. EOF exit 1 } @@ -112,6 +124,9 @@ while [[ "$1" = -* ]]; do --page-size) page_size="$arg" ;; + --earlycon) + earlycon="$arg" + ;; --help) usage ;; @@ -170,6 +185,26 @@ elif [ "$arch" = "arm" ] || [ "$arch" = "arm64" ]; then echo '--vmm must be one of "qemu" or "kvmtool"!' usage fi + + if [ "$earlycon" ]; then + name=$(echo $earlycon|cut -d',' -f1) + if [ "$name" != "uart" ] && [ "$name" != "uart8250" ] && + [ "$name" != "pl011" ]; then + echo "unknown earlycon name: $name" + usage + fi + type=$(echo $earlycon|cut -d',' -f2) + if [ "$type" != "mmio" ]; then + echo "unknown earlycon type: $type" + usage + fi + addr=$(echo $earlycon|cut -d',' -f3) + if [ -z "$addr" ]; then + echo "missing earlycon address" + usage + fi + arm_uart_early_addr=$addr + fi elif [ "$arch" = "ppc64" ]; then testdir=powerpc firmware="$testdir/boot_rom.bin" -- 2.30.1 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
