Multicore is also supported by QEMU via '-smp n' where n is the number of cores
to instantiate. Note, the maximum supported CPU number in QEMU is 255.
+U-Boot uses 'distro_bootcmd' by default when booting on x86 QEMU. This tries to
+load a boot script, kernel, and ramdisk from several different interfaces. For
+the default boot order, see 'qemu-x86.h'. For more information, see
+'README.distro'. Most Linux distros can be booted by writing a uboot script.
+For example, Debian (stretch) can be booted by creating a script file named
+'boot.txt' with the contents::
+
+ setenv bootargs root=/dev/sda1 ro
+ load ${devtype} ${devnum}:${distro_bootpart} ${kernel_addr_r} /vmlinuz
+ load ${devtype} ${devnum}:${distro_bootpart} ${ramdisk_addr_r} /initrd.img
+ zboot ${kernel_addr_r} - ${ramdisk_addr_r} ${filesize}
+
+Then compile and install it with::
+
+ $ apt install u-boot-tools && \
+ mkimage -T script -C none -n "Boot script" -d boot.txt /boot/boot.scr
+
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, which saves the time of loading them
#ifndef __CONFIG_H
#define __CONFIG_H
+#include <linux/sizes.h>
+
+#define BOOT_TARGET_DEVICES(func) \
+ func(USB, usb, 0) \
+ func(SCSI, scsi, 0) \
+ func(VIRTIO, virtio, 0) \
+ func(IDE, ide, 0) \
+ func(DHCP, dhcp, na)
+
+#include <config_distro_bootcmd.h>
#include <configs/x86-common.h>
+#undef CONFIG_ENV_SIZE
+#define CONFIG_ENV_SIZE SZ_256K
+
+#define CONFIG_PREBOOT "pci enum"
+
+#undef CONFIG_EXTRA_ENV_SETTINGS
+#define CONFIG_EXTRA_ENV_SETTINGS \
+ CONFIG_STD_DEVICES_SETTINGS \
+ "scriptaddr=0x7000000\0" \
+ "kernel_addr_r=0x1000000\0" \
+ "ramdisk_addr_r=0x4000000\0" \
+ "consoledev=ttyS0\0" \
+ CONFIG_OTHBOOTARGS \
+ BOOTENV
+
#define CONFIG_SYS_MONITOR_LEN (1 << 20)
#define CONFIG_STD_DEVICES_SETTINGS "stdin=serial,i8042-kbd\0" \