2015-12-28 18:05 GMT+08:00 Saket Sinha <saket.sinh...@gmail.com>: > Hi Miao, > > Thanks for the patches. > > I made an initial attempt to support the fw_cfg in U-boot for QEMU to > get acpi tables by fw_cfg for qemu-x86 targets. > > The idea was if we find acpi tables in fw_cfg try loading them, > otherwise fallback to the builtin acpi tables. > > The patch was dropped mainly because ACPI tables loaded by fw_cfg had > some issues which I could not figure out. > The patches were discussed(me, Simon and Bin) offline(off the mailing > list), so I am forwarding it to you and the community. > > If we can collaborate the patches in the sense that we are able to > load ACPI tables(and other tables) successfully, it would be great.
The main purpose of my patch is: + directly loads kernel from qemu + eliminate the cpu number limits in smp boot I am not familiar with the acpi part, but if you have a basic configuration to reproduce the error, maybe I can have a try. Thanks, Miao > > > Regards, > Saket Sinha > > > On Mon, Dec 28, 2015 at 2:48 PM, Miao Yan <yanmiaob...@gmail.com> wrote: >> The fw_cfg interface provided by QEMU allow guests to retrieve various >> information >> about the system, e.g. cpu number, variaous firmware data, kernel setup, >> etc. The >> fw_cfg interface can be accessed through 3 IO ports (on x86), using x86 >> in/out >> instructions. >> >> - 0x510: select configuration items to access >> - 0x511: reading this port will return data selected in 0x510 >> - 0x514: this can be used to detect if DMA interface is available >> >> If fw_cfg DMA interface is available, it can be used to accelerate >> accesses. >> >> This patchset adds the following supports for qemu-x86 targets: >> >> + the fw_cfg driver itself >> >> + add a U-Boot command 'fw' to support direct accessing kernel informtion >> from fw_cfg interface, this saves the time of loading them from hard >> disk or >> network again, through emulated devices. >> >> + use fw_cfg to get cpu number at runtime, so smp boot no longer relies on >> the cpu node hard-coded in dts files. >> >> Miao Yan (7): >> x86: qemu: add fw_cfg support >> x86: qemu: add a cpu uclass driver for qemu target >> x86: fix a typo in function name >> x86: qemu: use actual CPU number for allocating memory >> x86: qemu: add qemu_fwcfg_fdt_fixup() >> x86: qemu: fixup cpu node in device tree >> qemu-x86: add documentaion for the fw_cfg interface >> >> arch/x86/cpu/mp_init.c | 12 +- >> arch/x86/cpu/qemu/Makefile | 2 +- >> arch/x86/cpu/qemu/cpu.c | 58 ++++++++ >> arch/x86/cpu/qemu/fw_cfg.c | 281 >> +++++++++++++++++++++++++++++++++++++++ >> arch/x86/cpu/qemu/fw_cfg.h | 85 ++++++++++++ >> arch/x86/cpu/qemu/qemu.c | 7 + >> arch/x86/dts/qemu-x86_i440fx.dts | 18 +-- >> arch/x86/dts/qemu-x86_q35.dts | 19 +-- >> doc/README.x86 | 36 ++++- >> 9 files changed, 473 insertions(+), 45 deletions(-) >> create mode 100644 arch/x86/cpu/qemu/cpu.c >> create mode 100644 arch/x86/cpu/qemu/fw_cfg.c >> create mode 100644 arch/x86/cpu/qemu/fw_cfg.h >> >> -- >> 1.9.1 >> >> _______________________________________________ >> U-Boot mailing list >> U-Boot@lists.denx.de >> http://lists.denx.de/mailman/listinfo/u-boot _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot