board/qemu: ensure root is available before mounting it

On my machine, it happens once in a while that the virtualised machine
boots too fast for the rootfs to be available at the time the kernel
tries to mount it.

For example, board/qemu/arm-vexpress/readme.txt suggested changing
"-smp 1" up to "-smp 4". But doing so here causes a kernel panic:

    VFS: Cannot open root device "mmcblk0" or unknown-block(0,0): error -6
    Please append a correct "root=" boot option; here are the available partitions:
    1f00          131072 mtdblock0
     (driver?)
    1f01           32768 mtdblock1
     (driver?)
    Kernel panic - not syncing: VFS: Unable to mount root fs on
    unknown-block(0,0)

So, add the oh-so-useful 'rootwait' option to all kernel command lines
for qemu defconfigs.

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Mark Corbin <mark.corbin@embecosm.com>
Cc: Matt Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

diff --git a/board/qemu/aarch64-virt/readme.txt b/board/qemu/aarch64-virt/readme.txt
index 1ff2fba47d862123a8227606e71f4d6375d72f20..f868905d91926ab1076da45ce0923c4fec73cc21 100644 (file)
--- a/board/qemu/aarch64-virt/readme.txt
+++ b/board/qemu/aarch64-virt/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-  qemu-system-aarch64 -M virt -cpu cortex-a53 -nographic -smp 1 -kernel output/images/Image -append "root=/dev/vda console=ttyAMA0" -netdev user,id=eth0 -device virtio-net-device,netdev=eth0 -drive file=output/images/rootfs.ext4,if=none,format=raw,id=hd0 -device virtio-blk-device,drive=hd0
+  qemu-system-aarch64 -M virt -cpu cortex-a53 -nographic -smp 1 -kernel output/images/Image -append "rootwait root=/dev/vda console=ttyAMA0" -netdev user,id=eth0 -device virtio-net-device,netdev=eth0 -drive file=output/images/rootfs.ext4,if=none,format=raw,id=hd0 -device virtio-blk-device,drive=hd0
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/arm-versatile/readme.txt b/board/qemu/arm-versatile/readme.txt
index 33cdb7b81e5dfa9ce26fd2ae2c58290857e98fe6..f3a9e1ab4760a373555b29695aaee358c695d774 100644 (file)
--- a/board/qemu/arm-versatile/readme.txt
+++ b/board/qemu/arm-versatile/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-  qemu-system-arm -M versatilepb -kernel output/images/zImage -dtb output/images/versatile-pb.dtb -drive file=output/images/rootfs.ext2,if=scsi,format=raw -append "root=/dev/sda console=ttyAMA0,115200" -serial stdio -net nic,model=rtl8139 -net user
+  qemu-system-arm -M versatilepb -kernel output/images/zImage -dtb output/images/versatile-pb.dtb -drive file=output/images/rootfs.ext2,if=scsi,format=raw -append "rootwait root=/dev/sda console=ttyAMA0,115200" -serial stdio -net nic,model=rtl8139 -net user
 
 Or for the noMMU emulation:
 

diff --git a/board/qemu/arm-vexpress/readme.txt b/board/qemu/arm-vexpress/readme.txt
index 35137e050c134132c507be65ea82c33ff4db55bd..7f7b43a3b3bc6c1416e497dc8515e20b85141245 100644 (file)
--- a/board/qemu/arm-vexpress/readme.txt
+++ b/board/qemu/arm-vexpress/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-  qemu-system-arm -M vexpress-a9 -smp 1 -m 256 -kernel output/images/zImage -dtb output/images/vexpress-v2p-ca9.dtb -drive file=output/images/rootfs.ext2,if=sd,format=raw -append "console=ttyAMA0,115200 root=/dev/mmcblk0" -serial stdio -net nic,model=lan9118 -net user
+  qemu-system-arm -M vexpress-a9 -smp 1 -m 256 -kernel output/images/zImage -dtb output/images/vexpress-v2p-ca9.dtb -drive file=output/images/rootfs.ext2,if=sd,format=raw -append "console=ttyAMA0,115200 rootwait root=/dev/mmcblk0" -serial stdio -net nic,model=lan9118 -net user
 
 The login prompt will appear in the terminal that started Qemu. The
 graphical window is the framebuffer.

diff --git a/board/qemu/m68k-q800/readme.txt b/board/qemu/m68k-q800/readme.txt
index bead8cdde29c5c9057d26e0c173d42aff542c775..b516bacdff13c04a8f8c4091fca44a3f114b1052 100644 (file)
--- a/board/qemu/m68k-q800/readme.txt
+++ b/board/qemu/m68k-q800/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
- qemu-system-m68k -M q800 -kernel output/images/vmlinux -nographic -drive file=output/images/rootfs.ext2,format=raw -append "root=/dev/sda console=ttyS0"
+ qemu-system-m68k -M q800 -kernel output/images/vmlinux -nographic -drive file=output/images/rootfs.ext2,format=raw -append "rootwait root=/dev/sda console=ttyS0"
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/mips32r2-malta/readme.txt b/board/qemu/mips32r2-malta/readme.txt
index d1bbcc47490c36b4eb4915b1805499172c7663dd..9ff3c4b810510d4021ccfd4f7675a31cf7b1ad05 100644 (file)
--- a/board/qemu/mips32r2-malta/readme.txt
+++ b/board/qemu/mips32r2-malta/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
- qemu-system-mips -M malta -kernel output/images/vmlinux -serial stdio -drive file=output/images/rootfs.ext2,format=raw -append "root=/dev/hda" -net nic,model=pcnet -net user
+ qemu-system-mips -M malta -kernel output/images/vmlinux -serial stdio -drive file=output/images/rootfs.ext2,format=raw -append "rootwait root=/dev/hda" -net nic,model=pcnet -net user
 
 The login prompt will appear in the terminal that started Qemu. The
 graphical window is the framebuffer. No keyboard support has been

diff --git a/board/qemu/mips32r2el-malta/readme.txt b/board/qemu/mips32r2el-malta/readme.txt
index 4f59d34308d0d46dcab36c12f6fb718fbab16300..745bfea608c82300b7b0319c83eb166a2bb88c4a 100644 (file)
--- a/board/qemu/mips32r2el-malta/readme.txt
+++ b/board/qemu/mips32r2el-malta/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
- qemu-system-mipsel -M malta -kernel output/images/vmlinux -serial stdio -drive file=output/images/rootfs.ext2,format=raw -append "root=/dev/hda" -net nic,model=pcnet -net user
+ qemu-system-mipsel -M malta -kernel output/images/vmlinux -serial stdio -drive file=output/images/rootfs.ext2,format=raw -append "rootwait root=/dev/hda" -net nic,model=pcnet -net user
 
 The login prompt will appear in the terminal that started Qemu. The
 graphical window is the framebuffer. No keyboard support has been

diff --git a/board/qemu/mips32r6-malta/readme.txt b/board/qemu/mips32r6-malta/readme.txt
index 04de7e5c3e6dc1c77bb621d24ee7b8d9094b5208..6a026b21651305c6c7d5893a03fdc0c451c4e082 100644 (file)
--- a/board/qemu/mips32r6-malta/readme.txt
+++ b/board/qemu/mips32r6-malta/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-qemu-system-mips -M malta -cpu mips32r6-generic -kernel output/images/vmlinux -drive file=output/images/rootfs.ext2,format=raw -append "root=/dev/hda" -nographic
+qemu-system-mips -M malta -cpu mips32r6-generic -kernel output/images/vmlinux -drive file=output/images/rootfs.ext2,format=raw -append "rootwait root=/dev/hda" -nographic
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/mips32r6el-malta/readme.txt b/board/qemu/mips32r6el-malta/readme.txt
index 88602de0bbaf05f7a6cc3689de010e8a42e04e3f..f69fd21af1ccb274fe8261c679c726d2c255f465 100644 (file)
--- a/board/qemu/mips32r6el-malta/readme.txt
+++ b/board/qemu/mips32r6el-malta/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-qemu-system-mipsel -M malta -cpu mips32r6-generic -kernel output/images/vmlinux -drive file=output/images/rootfs.ext2,format=raw -append "root=/dev/hda" -net nic,model=pcnet -net user -nographic
+qemu-system-mipsel -M malta -cpu mips32r6-generic -kernel output/images/vmlinux -drive file=output/images/rootfs.ext2,format=raw -append "rootwait root=/dev/hda" -net nic,model=pcnet -net user -nographic
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/mips64-malta/readme.txt b/board/qemu/mips64-malta/readme.txt
index f0e7fef79579cc9ef22d1a0d36ab39c0099ba163..ea3a92541e09aeb333b033e6e22d6d0c30386dda 100644 (file)
--- a/board/qemu/mips64-malta/readme.txt
+++ b/board/qemu/mips64-malta/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
- qemu-system-mips64 -M malta -kernel output/images/vmlinux -serial stdio -drive file=output/images/rootfs.ext2,format=raw -append "root=/dev/hda"
+ qemu-system-mips64 -M malta -kernel output/images/vmlinux -serial stdio -drive file=output/images/rootfs.ext2,format=raw -append "rootwait root=/dev/hda"
 
 The login prompt will appear in the terminal that started Qemu. The
 graphical window is the framebuffer.

diff --git a/board/qemu/mips64el-malta/readme.txt b/board/qemu/mips64el-malta/readme.txt
index 03b149bc8fa12c454b61de1149144f18d994f7de..144da93839f65bbc33cbb559fc0bc9dddd70d261 100644 (file)
--- a/board/qemu/mips64el-malta/readme.txt
+++ b/board/qemu/mips64el-malta/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
- qemu-system-mips64el -M malta -kernel output/images/vmlinux -serial stdio -drive file=output/images/rootfs.ext2,format=raw -append "root=/dev/hda"
+ qemu-system-mips64el -M malta -kernel output/images/vmlinux -serial stdio -drive file=output/images/rootfs.ext2,format=raw -append "rootwait root=/dev/hda"
 
 The login prompt will appear in the terminal that started Qemu. The
 graphical window is the framebuffer.

diff --git a/board/qemu/mips64r6-malta/readme.txt b/board/qemu/mips64r6-malta/readme.txt
index bf5b517a3204cd68cc02cfda6f9ca9293e3d3378..cfa16fd8638a37ee52bcb32d8e182ab921f48bf6 100644 (file)
--- a/board/qemu/mips64r6-malta/readme.txt
+++ b/board/qemu/mips64r6-malta/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
- qemu-system-mips64 -M malta -cpu I6400 -kernel output/images/vmlinux -drive file=output/images/rootfs.ext2,format=raw -append "root=/dev/hda" -nographic
+ qemu-system-mips64 -M malta -cpu I6400 -kernel output/images/vmlinux -drive file=output/images/rootfs.ext2,format=raw -append "rootwait root=/dev/hda" -nographic
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/mips64r6el-malta/readme.txt b/board/qemu/mips64r6el-malta/readme.txt
index d51bffd08a5d9ffe1dc324f7f464236edbf3cf79..61a6ceb5f40a65249686a14183005885d91a0594 100644 (file)
--- a/board/qemu/mips64r6el-malta/readme.txt
+++ b/board/qemu/mips64r6el-malta/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
- qemu-system-mips64el -M malta -cpu I6400 -kernel output/images/vmlinux -drive file=output/images/rootfs.ext2,format=raw -append "root=/dev/hda" -nographic
+ qemu-system-mips64el -M malta -cpu I6400 -kernel output/images/vmlinux -drive file=output/images/rootfs.ext2,format=raw -append "rootwait root=/dev/hda" -nographic
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/ppc-g3beige/readme.txt b/board/qemu/ppc-g3beige/readme.txt
index 1c3b5153969dca4e6bcb36da0f14f9f0a87d70bf..608814ee3b1ae72847f57fb2431ec4d844702002 100644 (file)
--- a/board/qemu/ppc-g3beige/readme.txt
+++ b/board/qemu/ppc-g3beige/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-  qemu-system-ppc -M g3beige -kernel output/images/vmlinux -drive file=output/images/rootfs.ext2,format=raw -append "console=ttyS0 root=/dev/hda" -serial stdio -net nic,model=rtl8139 -net user
+  qemu-system-ppc -M g3beige -kernel output/images/vmlinux -drive file=output/images/rootfs.ext2,format=raw -append "console=ttyS0 rootwait root=/dev/hda" -serial stdio -net nic,model=rtl8139 -net user
 
 The login prompt will appear in the terminal that started Qemu. The
 graphical window is the framebuffer.

diff --git a/board/qemu/ppc64-e5500/readme.txt b/board/qemu/ppc64-e5500/readme.txt
index cfc563974d20a45ee794776b111d87115459ab6a..8080766984ba3ba49871c118e175847ec7f2cab1 100644 (file)
--- a/board/qemu/ppc64-e5500/readme.txt
+++ b/board/qemu/ppc64-e5500/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
- qemu-system-ppc64 -M ppce500 -cpu e5500 -m 256 -kernel output/images/uImage -drive file=output/images/rootfs.ext2,if=virtio,format=raw -append "console=ttyS0 root=/dev/vda" -serial mon:stdio -nographic
+ qemu-system-ppc64 -M ppce500 -cpu e5500 -m 256 -kernel output/images/uImage -drive file=output/images/rootfs.ext2,if=virtio,format=raw -append "console=ttyS0 rootwait root=/dev/vda" -serial mon:stdio -nographic
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/ppc64-pseries/readme.txt b/board/qemu/ppc64-pseries/readme.txt
index 5069df9e5bc9cc7a13a3697b09e31498054d51e9..6a3e96a2e5dc1288ffc81f837e584f7bc4669e51 100644 (file)
--- a/board/qemu/ppc64-pseries/readme.txt
+++ b/board/qemu/ppc64-pseries/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
- qemu-system-ppc64 -M pseries -cpu POWER7 -m 256 -kernel output/images/vmlinux -append "console=hvc0 root=/dev/sda" -drive file=output/images/rootfs.ext2,if=scsi,index=0,format=raw -serial stdio -display curses
+ qemu-system-ppc64 -M pseries -cpu POWER7 -m 256 -kernel output/images/vmlinux -append "console=hvc0 rootwait root=/dev/sda" -drive file=output/images/rootfs.ext2,if=scsi,index=0,format=raw -serial stdio -display curses
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/ppc64le-pseries/readme.txt b/board/qemu/ppc64le-pseries/readme.txt
index c23da70df002d075ead286dae0f9d19b5d4b08ad..2728675df2ac11e41f88bdc2448cbd50e8e60195 100644 (file)
--- a/board/qemu/ppc64le-pseries/readme.txt
+++ b/board/qemu/ppc64le-pseries/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-qemu-system-ppc64 -M pseries -cpu POWER8 -m 256 -kernel output/images/vmlinux -append "console=hvc0 root=/dev/sda" -drive file=output/images/rootfs.ext2,if=scsi,index=0,format=raw -serial stdio -display curses
+qemu-system-ppc64 -M pseries -cpu POWER8 -m 256 -kernel output/images/vmlinux -append "console=hvc0 rootwait root=/dev/sda" -drive file=output/images/rootfs.ext2,if=scsi,index=0,format=raw -serial stdio -display curses
 
 The login prompt will appear in the terminal window.
 

diff --git a/board/qemu/riscv32-virt/readme.txt b/board/qemu/riscv32-virt/readme.txt
index b984e47105e3a11d997e5c34eddc4b4620d9b5f9..5d7c1988d29b178e8e5f8a554e3f15d88638ea3a 100644 (file)
--- a/board/qemu/riscv32-virt/readme.txt
+++ b/board/qemu/riscv32-virt/readme.txt
@@ -1,6 +1,6 @@
 Run Linux in emulation with:
 
-  qemu-system-riscv32 -M virt -kernel output/images/fw_jump.elf -device loader,file=output/images/Image,addr=0x80400000 -append "root=/dev/vda ro" -drive file=output/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -netdev user,id=net0 -device virtio-net-device,netdev=net0 -nographic
+  qemu-system-riscv32 -M virt -kernel output/images/fw_jump.elf -device loader,file=output/images/Image,addr=0x80400000 -append "rootwait root=/dev/vda ro" -drive file=output/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -netdev user,id=net0 -device virtio-net-device,netdev=net0 -nographic
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/riscv64-virt/readme.txt b/board/qemu/riscv64-virt/readme.txt
index 84c7ab3221fd56fef8b9af8c744c0ca9dba4bb3b..c075cc464d73217640fad5967389acf3263c76bb 100644 (file)
--- a/board/qemu/riscv64-virt/readme.txt
+++ b/board/qemu/riscv64-virt/readme.txt
@@ -1,6 +1,6 @@
 Run Linux in emulation with:
 
-  qemu-system-riscv64 -M virt -kernel output/images/fw_jump.elf -device loader,file=output/images/Image,addr=0x80200000 -append "root=/dev/vda ro" -drive file=output/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -netdev user,id=net0 -device virtio-net-device,netdev=net0 -nographic
+  qemu-system-riscv64 -M virt -kernel output/images/fw_jump.elf -device loader,file=output/images/Image,addr=0x80200000 -append "rootwait root=/dev/vda ro" -drive file=output/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -netdev user,id=net0 -device virtio-net-device,netdev=net0 -nographic
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/sh4-r2d/readme.txt b/board/qemu/sh4-r2d/readme.txt
index d22af73ae359dce4aab79302cfcedb34ea5af0c3..dd80953b971487d0773c95086b9f86089f14aa58 100644 (file)
--- a/board/qemu/sh4-r2d/readme.txt
+++ b/board/qemu/sh4-r2d/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-  qemu-system-sh4 -M r2d -kernel output/images/zImage -drive file=output/images/rootfs.ext2,if=ide,format=raw -append "root=/dev/sda console=ttySC1,115200 noiotrap" -serial null -serial stdio -net nic,model=rtl8139 -net user
+  qemu-system-sh4 -M r2d -kernel output/images/zImage -drive file=output/images/rootfs.ext2,if=ide,format=raw -append "rootwait root=/dev/sda console=ttySC1,115200 noiotrap" -serial null -serial stdio -net nic,model=rtl8139 -net user
 
 The login prompt will appear in the terminal that started Qemu.
 The graphical window is the framebuffer.

diff --git a/board/qemu/sh4eb-r2d/readme.txt b/board/qemu/sh4eb-r2d/readme.txt
index daf515ab2b135fa2cf5d55119dcc495bdbe01f0d..e71a9bce90eb90873f94445acb39fa7baca1daef 100644 (file)
--- a/board/qemu/sh4eb-r2d/readme.txt
+++ b/board/qemu/sh4eb-r2d/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-  qemu-system-sh4eb -M r2d -kernel output/images/zImage -drive file=output/images/rootfs.ext2,if=ide,format=raw -append "root=/dev/sda console=ttySC1,115200 noiotrap" -serial null -serial stdio -net nic,model=rtl8139 -net user
+  qemu-system-sh4eb -M r2d -kernel output/images/zImage -drive file=output/images/rootfs.ext2,if=ide,format=raw -append "rootwait root=/dev/sda console=ttySC1,115200 noiotrap" -serial null -serial stdio -net nic,model=rtl8139 -net user
 
 The login prompt will appear in the terminal that started Qemu.
 The graphical window is the framebuffer.

diff --git a/board/qemu/sparc-ss10/readme.txt b/board/qemu/sparc-ss10/readme.txt
index df6a75a3fbcfafa16ea6560cef39ca9ff020cd06..33833c2d33d8d269caa74d791a80ad5cce37d583 100644 (file)
--- a/board/qemu/sparc-ss10/readme.txt
+++ b/board/qemu/sparc-ss10/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-  qemu-system-sparc -M SS-10 -kernel output/images/zImage -drive file=output/images/rootfs.ext2,format=raw -append "root=/dev/sda console=ttyS0,115200" -serial stdio -net nic,model=lance -net user
+  qemu-system-sparc -M SS-10 -kernel output/images/zImage -drive file=output/images/rootfs.ext2,format=raw -append "rootwait root=/dev/sda console=ttyS0,115200" -serial stdio -net nic,model=lance -net user
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/sparc64-sun4u/readme.txt b/board/qemu/sparc64-sun4u/readme.txt
index 24d5bbaffe908565ee200a78f8b6e128bd316271..f2e6e81a86408a9de466978a53c9029d32e97057 100644 (file)
--- a/board/qemu/sparc64-sun4u/readme.txt
+++ b/board/qemu/sparc64-sun4u/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-  qemu-system-sparc64 -M sun4u -kernel output/images/vmlinux -append "root=/dev/sda console=ttyS0,115200" -serial stdio -drive file=output/images/rootfs.ext2,format=raw -net nic,model=e1000 -net user
+  qemu-system-sparc64 -M sun4u -kernel output/images/vmlinux -append "rootwait root=/dev/sda console=ttyS0,115200" -serial stdio -drive file=output/images/rootfs.ext2,format=raw -net nic,model=e1000 -net user
 
 The login prompt will appear in the terminal that started Qemu.
 

diff --git a/board/qemu/x86/readme.txt b/board/qemu/x86/readme.txt
index c5e687734c5eae8dd1791a1e0b5657369994d8b5..42fc2439da3fb2a3ac72ec7a7855fefe220154c7 100644 (file)
--- a/board/qemu/x86/readme.txt
+++ b/board/qemu/x86/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-  qemu-system-i386 -M pc -kernel output/images/bzImage -drive file=output/images/rootfs.ext2,if=virtio,format=raw -append "root=/dev/vda" -net nic,model=virtio -net user
+  qemu-system-i386 -M pc -kernel output/images/bzImage -drive file=output/images/rootfs.ext2,if=virtio,format=raw -append "rootwait root=/dev/vda" -net nic,model=virtio -net user
 
 Optionally add -smp N to emulate a SMP system with N CPUs.
 

diff --git a/board/qemu/x86_64/readme.txt b/board/qemu/x86_64/readme.txt
index 425e34b12ce888adfc7fd452f4ce2aff3a2ed88c..4a1c0c0ff57c542c6871fffd7df2fed98df8a0a3 100644 (file)
--- a/board/qemu/x86_64/readme.txt
+++ b/board/qemu/x86_64/readme.txt
@@ -1,6 +1,6 @@
 Run the emulation with:
 
-  qemu-system-x86_64 -M pc -kernel output/images/bzImage -drive file=output/images/rootfs.ext2,if=virtio,format=raw -append "root=/dev/vda" -net nic,model=virtio -net user
+  qemu-system-x86_64 -M pc -kernel output/images/bzImage -drive file=output/images/rootfs.ext2,if=virtio,format=raw -append "rootwait root=/dev/vda" -net nic,model=virtio -net user
 
 Optionally add -smp N to emulate a SMP system with N CPUs.