Document the usage of 'qfw' command
Signed-off-by: Miao Yan yanmiaobest@gmail.com Reviewed-by: Simon Glass sjg@chromium.org Reviewed-by: Bin Meng bmeng.cn@gmail.com --- Changes in v5: - maximum supported is 255 now which is imposed by QEMU - 'fw' to 'qfw'
doc/README.x86 | 34 +++++++++++++++++++++++++++++++--- 1 file changed, 31 insertions(+), 3 deletions(-)
diff --git a/doc/README.x86 b/doc/README.x86 index 1271e5e..36aaef0 100644 --- a/doc/README.x86 +++ b/doc/README.x86 @@ -295,9 +295,37 @@ show QEMU's VGA console window. Note this will disable QEMU's serial output. If you want to check both consoles, use '-serial stdio'.
Multicore is also supported by QEMU via '-smp n' where n is the number of cores -to instantiate. Currently the default U-Boot built for QEMU supports 2 cores. -In order to support more cores, you need add additional cpu nodes in the device -tree and change CONFIG_MAX_CPUS accordingly. +to instantiate. Note, the maximum supported CPU number in QEMU is 255. + +The fw_cfg interface in QEMU also provides information about kernel data, initrd, +command-line arguments and more. U-Boot supports directly accessing these informtion +from fw_cfg interface, this saves the time of loading them from hard disk or +network again, through emulated devices. To use it , simply providing them in +QEMU command line: + +$ qemu-system-i386 -nographic -bios path/to/u-boot.rom -m 1024 -kernel /path/to/bzImage + -append 'root=/dev/ram console=ttyS0' -initrd /path/to/initrd -smp 8 + +Note: -initrd and -smp are both optional + +Then start QEMU, in U-Boot command line use the following U-Boot command to setup kernel: + + => qfw +qfw - QEMU firmware interface + +Usage: +qfw <command> + - list : print firmware(s) currently loaded + - cpus : print online cpu number + - load <kernel addr> <initrd addr> : load kernel and initrd (if any) and setup for zboot + +=> qfw load +loading kernel to address 01000000 size 5d9d30 initrd 04000000 size 1b1ab50 + +Here the kernel (bzImage) is loaded to 01000000 and initrd is to 04000000. Then, 'zboot' +can be used to boot the kernel: + +=> zboot 02000000 - 04000000 1b1ab50
CPU Microcode -------------