[U-Boot] [PATCH v3] qemu-x86: Use config_distro_bootcmd

Joshua Watt
2019-07-03T17:45:32Z

Converts qemu x86 machines to boot using distro_config. The intent is to
allow u-boot in qemu to be maximally compatible with many boot methods
without having to change the config. Previously, u-boot would only boot
in a very limited set of circumstances where there was a /boot/vmlinuz
on scsi 0:3 with no ramdisk.

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
---
configs/qemu-x86_64_defconfig | 1 +
configs/qemu-x86_defconfig | 1 +
doc/README.x86 | 17 +++++++++++++++++
include/configs/qemu-x86.h | 25 +++++++++++++++++++++++++
4 files changed, 44 insertions(+)

diff --git a/configs/qemu-x86_64_defconfig b/configs/qemu-x86_64_defconfig
index d89cd44144..89118cc3dc 100644
--- a/configs/qemu-x86_64_defconfig
+++ b/configs/qemu-x86_64_defconfig
@@ -12,6 +12,7 @@ CONFIG_SMP=y
CONFIG_GENERATE_PIRQ_TABLE=y
CONFIG_GENERATE_MP_TABLE=y
CONFIG_GENERATE_ACPI_TABLE=y
+CONFIG_DISTRO_DEFAULTS=y
CONFIG_BUILD_ROM=y
CONFIG_FIT=y
CONFIG_SPL_LOAD_FIT=y
diff --git a/configs/qemu-x86_defconfig b/configs/qemu-x86_defconfig
index 898d656ac3..a50285beec 100644
--- a/configs/qemu-x86_defconfig
+++ b/configs/qemu-x86_defconfig
@@ -6,6 +6,7 @@ CONFIG_SMP=y
CONFIG_GENERATE_PIRQ_TABLE=y
CONFIG_GENERATE_MP_TABLE=y
CONFIG_GENERATE_ACPI_TABLE=y
+CONFIG_DISTRO_DEFAULTS=y
CONFIG_BUILD_ROM=y
CONFIG_FIT=y
CONFIG_BOOTSTAGE=y
diff --git a/doc/README.x86 b/doc/README.x86
index 8e0a3f36ed..a00ae69acc 100644
--- a/doc/README.x86
+++ b/doc/README.x86
@@ -466,6 +466,23 @@ 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. 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
diff --git a/include/configs/qemu-x86.h b/include/configs/qemu-x86.h
index 64e7a60b8a..097ed414f8 100644
--- a/include/configs/qemu-x86.h
+++ b/include/configs/qemu-x86.h
@@ -10,8 +10,33 @@
#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" \
--
2.21.0