From: Bin Meng <bmeng.cn@gmail.com>
To: Alistair Francis <alistair.francis@wdc.com>,
qemu-devel@nongnu.org, qemu-riscv@nongnu.org
Cc: Bin Meng <bin.meng@windriver.com>
Subject: [PATCH v2 6/8] docs/system/riscv: sifive_u: Document '-dtb' usage
Date: Fri, 30 Apr 2021 15:13:00 +0800 [thread overview]
Message-ID: <20210430071302.1489082-6-bmeng.cn@gmail.com> (raw)
In-Reply-To: <20210430071302.1489082-1-bmeng.cn@gmail.com>
From: Bin Meng <bin.meng@windriver.com>
Update the 'sifive_u' machine documentation to mention the '-dtb'
option that can be used to pass a custom DTB to QEMU.
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
(no changes since v1)
docs/system/riscv/sifive_u.rst | 47 +++++++++++++++++++++++++++++-----
1 file changed, 41 insertions(+), 6 deletions(-)
diff --git a/docs/system/riscv/sifive_u.rst b/docs/system/riscv/sifive_u.rst
index dcdfbda931..32d0a1b85d 100644
--- a/docs/system/riscv/sifive_u.rst
+++ b/docs/system/riscv/sifive_u.rst
@@ -36,12 +36,21 @@ Hardware configuration information
----------------------------------
The ``sifive_u`` machine automatically generates a device tree blob ("dtb")
-which it passes to the guest. This provides information about the addresses,
-interrupt lines and other configuration of the various devices in the system.
-Guest software should discover the devices that are present in the generated
-DTB instead of using a DTB for the real hardware, as some of the devices are
-not modeled by QEMU and trying to access these devices may cause unexpected
-behavior.
+which it passes to the guest, if there is no ``-dtb`` option. This provides
+information about the addresses, interrupt lines and other configuration of
+the various devices in the system. Guest software should discover the devices
+that are present in the generated DTB instead of using a DTB for the real
+hardware, as some of the devices are not modeled by QEMU and trying to access
+these devices may cause unexpected behavior.
+
+If users want to provide their own DTB, they can use the ``-dtb`` option.
+These DTBs should have the following requirements:
+
+* The /cpus node should contain at least one subnode for E51 and the number
+ of subnodes should match QEMU's ``-smp`` option
+* The /memory reg size should match QEMU’s selected ram_size via ``-m``
+* Should contain a node for the CLINT device with a compatible string
+ "riscv,clint0" if using with OpenSBI BIOS images
Boot options
------------
@@ -122,6 +131,32 @@ To boot the newly built Linux kernel in QEMU with the ``sifive_u`` machine:
-initrd /path/to/rootfs.ext4 \
-append "root=/dev/ram"
+Alternatively, we can use a custom DTB to boot the machine by inserting a CLINT
+node in fu540-c000.dtsi in the Linux kernel,
+
+.. code-block:: none
+
+ clint: clint@2000000 {
+ compatible = "riscv,clint0";
+ interrupts-extended = <&cpu0_intc 3 &cpu0_intc 7
+ &cpu1_intc 3 &cpu1_intc 7
+ &cpu2_intc 3 &cpu2_intc 7
+ &cpu3_intc 3 &cpu3_intc 7
+ &cpu4_intc 3 &cpu4_intc 7>;
+ reg = <0x00 0x2000000 0x00 0x10000>;
+ };
+
+with the following command line options:
+
+.. code-block:: bash
+
+ $ qemu-system-riscv64 -M sifive_u -smp 5 -m 8G \
+ -display none -serial stdio \
+ -kernel arch/riscv/boot/Image \
+ -dtb arch/riscv/boot/dts/sifive/hifive-unleashed-a00.dtb \
+ -initrd /path/to/rootfs.ext4 \
+ -append "root=/dev/ram"
+
To build a Linux mainline kernel that can be booted by the ``sifive_u`` machine
in 32-bit mode, use the rv32_defconfig configuration. A patch is required to
fix the 32-bit boot issue for Linux kernel v5.10.
--
2.25.1
next prev parent reply other threads:[~2021-04-30 7:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-30 7:12 [PATCH v2 1/8] hw/riscv: sifive_u: Switch to use qemu_fdt_setprop_string_array() helper Bin Meng
2021-04-30 7:12 ` [PATCH v2 2/8] hw/riscv: virt: " Bin Meng
2021-04-30 7:12 ` [PATCH v2 3/8] hw/riscv: Support the official CLINT DT bindings Bin Meng
2021-04-30 7:12 ` [PATCH v2 4/8] hw/riscv: Support the official PLIC " Bin Meng
2021-04-30 7:12 ` [PATCH v2 5/8] docs/system/riscv: Correct the indentation level of supported devices Bin Meng
2021-05-03 3:00 ` Alistair Francis
2021-04-30 7:13 ` Bin Meng [this message]
2021-04-30 7:13 ` [PATCH v2 7/8] hw/riscv: Use macros for BIOS image names Bin Meng
2021-04-30 7:13 ` [PATCH v2 8/8] hw/riscv: microchip_pfsoc: Support direct kernel boot Bin Meng
2021-05-31 2:33 ` [PATCH v2 1/8] hw/riscv: sifive_u: Switch to use qemu_fdt_setprop_string_array() helper Bin Meng
2021-06-01 6:41 ` Alistair Francis
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