U-Boot can start and boot an OS in both qemu-x86 and qemu-x86_64 but it is not perfect.
With both builds, executing the VESA ROM causes an intermittent hang, at least on some AMD CPUs. With qemu-x86_64 kvm cannot be used since the move to long mode (64-bit) is done in a way that works on real hardware but not with QEMU. This means that performance is 4-5x slower than it could be, at least on my CPU. We can work around the first problem by using Bochs, which is anyway a better choice than VESA for QEMU. The second can be addressed by using the same descriptor across the jump to long mode. With an MTRR fix this allows booting into Ubuntu on qemu-x86_64 Changes in v2: - Redo commit message - Add new patch to rename the _D dirty flag - Add new patch to support CPU functions in long mode - Add new patch to tidy up address size in MTRR calculations - Add new patch with a 64-bit version of is_power_of_2() - Add new patch to set an MTRR for the RAM in QEMU - Add new patch with a helper to send characters - Add new patch to allow tests to be filtered by role - Add more patches to support booting with kvm - Add new patch with a test for booting Ubuntu 24.04 Simon Glass (28): x86: Expand x86_64 early memory x86: qemu: Switch to bochs display x86: qemu: Enable dhrystone x86: qemu: Avoid accessing BSS too early x86: Drop mpspec from the SPL build x86: Add some log categories x86: Drop use of CONFIG_REALMODE_DEBUG x86: Avoid clearing the VESA display x86: Add 64-bit entries to the GDT x86: Use defines for the cache flags x86: spl: Drop duplicate CPU init x86: Drop the message about features missing in 64-bit x86: Include stdbool.h in interrupt header x86: Tidy up the GDT size in start/16.S x86: Disable paging before changing to long mode x86: Use the same GDT when jumping to long mode x86: Use a simple jump into long mode x86: Rename the _D dirty flag x86: Support CPU functions in long mode x86: Tidy up address size in MTRR calculations Add a 64-bit version of is_power_of_2() x86: Support MTRRs of 4GB on 32-bit machines x86: emulation: Set an MTRR for the RAM scripts: Expand a few options test/py: Add a helper to send characters test/py: Allow tests to be filtered by role RFC: test/py: Deal with timeouts test: Add a test for booting Ubuntu 24.04 .gitlab-ci.yml | 5 +++ arch/x86/cpu/cpu.c | 24 +++++++++++++++ arch/x86/cpu/i386/call64.S | 35 +++++++++------------ arch/x86/cpu/i386/cpu.c | 41 +++++++++--------------- arch/x86/cpu/mtrr.c | 12 +++++--- arch/x86/cpu/qemu/dram.c | 15 +++++++++ arch/x86/cpu/qemu/qemu.c | 20 ++++++++---- arch/x86/cpu/start.S | 4 ++- arch/x86/cpu/start16.S | 3 +- arch/x86/cpu/x86_64/cpu.c | 5 --- arch/x86/include/asm/cpu.h | 35 ++++++++++++++++++--- arch/x86/include/asm/interrupt.h | 1 + arch/x86/include/asm/processor.h | 5 ++- arch/x86/lib/Makefile | 2 ++ arch/x86/lib/bios.c | 27 +++++++++------- arch/x86/lib/bios_interrupts.c | 8 ++--- arch/x86/lib/i8259.c | 2 ++ arch/x86/lib/spl.c | 4 +-- configs/qemu-x86_64_defconfig | 10 +++--- configs/qemu-x86_defconfig | 6 ++-- include/linux/log2.h | 6 ++++ scripts/build-qemu.sh | 4 +-- test/py/conftest.py | 22 +++++++++++++ test/py/console_base.py | 33 ++++++++++++-------- test/py/pytest.ini | 1 + test/py/tests/test_distro.py | 53 ++++++++++++++++++++++++++++++++ test/py/tests/test_sleep.py | 1 + 27 files changed, 273 insertions(+), 111 deletions(-) create mode 100644 test/py/tests/test_distro.py -- 2.43.0
