Hi Heinrich, On Thu, Oct 11, 2018 at 11:32 PM Heinrich Schuchardt <xypron.g...@gmx.de> wrote: > > On 10/11/2018 05:27 PM, Bin Meng wrote: > > Hi Heinrich, > > > > On Thu, Oct 11, 2018 at 11:15 PM Heinrich Schuchardt <xypron.g...@gmx.de> > > wrote: > >> > >> On 10/11/2018 03:53 AM, Bin Meng wrote: > >>> Currently only 32-bit U-Boot for QEMU x86 is documented. Mention > >>> the 64-bit support. > >>> > >>> Signed-off-by: Bin Meng <bmeng...@gmail.com> > >>> --- > >>> > >>> doc/README.x86 | 8 ++++++-- > >>> 1 file changed, 6 insertions(+), 2 deletions(-) > >>> > >>> diff --git a/doc/README.x86 b/doc/README.x86 > >>> index 8cc4672..ab48466 100644 > >>> --- a/doc/README.x86 > >>> +++ b/doc/README.x86 > >>> @@ -32,7 +32,7 @@ are supported: > >>> - Link (Chromebook Pixel) > >>> - Minnowboard MAX > >>> - Samus (Chromebook Pixel 2015) > >>> - - QEMU x86 > >>> + - QEMU x86 (32-bit & 64-bit) > >>> > >>> As for loading an OS, U-Boot supports directly booting a 32-bit or 64-bit > >>> Linux kernel as part of a FIT image. It also supports a compressed > >>> zImage. > >>> @@ -376,7 +376,9 @@ QEMU x86 target instructions for bare mode: > >>> > >>> To build u-boot.rom for QEMU x86 targets, just simply run > >>> > >>> -$ make qemu-x86_defconfig > >>> +$ make qemu-x86_defconfig (for 32-bit) > >>> +or > >>> +$ make qemu-x86_64_defconfig (for 64-bit) > >>> $ make all > >> > >> If your patch series creates a U-Boot usable with QEMU depends on the > >> chosen CPU: > >> > >> This one seems to work: > >> qemu-system-x86_64 -bios u-boot.rom -nographic -cpu core2duo > >> > >> This one fails (as expected): > >> qemu-system-x86_64 -bios u-boot.rom --nographic -cpu pentium > > > > Pentium does not support 64-bit, so it is expected. In my testing I > > always omit the '-cpu' so this is not a problem. But I can document > > this. > > > >> > >> I could not get the emulation running without -nographic. Do you know why? > >> > > > > This is due to currently the VGA support is missing in the 64-bit U-Boot. > > > >> The documentation above is insufficient. Please, provide a minimum QEMU > >> command line which includes a CPU specification. > >> > >> I would prefer if you could specify two lines per bitness - one with kvm > >> and one without, e.g. > > > > I doubt -enable-kvm works with U-Boot. > > Why? It is just an instruction how QEMU should emulate the CPU. KVM does > not require anything on the target software side. > > I have had no problem with KVM on the i386 target.
I suspect some drivers may have issues when working with KVM, eg: some memory barriers might be needed due to guest (U-Boot) and host (x86 machine) are speaking the same language. But I have never fully test this configuration. Regards, Bin _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
