mirror of
https://github.com/riscv-software-src/opensbi.git
synced 2026-05-23 14:21:32 +01:00
Zhang RunMin
3d8f1f3864
When using GDB for debugging, if FW_TEXT_START is not set to 0x80000000
during compilation, the following error occurs:
Reading symbols from build/platform/generic/firmware/fw_payload.elf...
Remote debugging using localhost:1234
mips_warm_boot ()
at /home/zrmin/opensbi/platform/generic/mips/mips_warm_boot.S:11
11 j _start_warm
(gdb) b _start
Breakpoint 1 at 0x0: file /home/zrmin/opensbi/firmware/fw_base.S, line 50.
(gdb) c
Continuing.
Remote connection closed
(gdb)
With FW_TEXT_START=0x80000000, debugging works correctly:
Reading symbols from build/platform/generic/firmware/fw_payload.elf...
Remote debugging using localhost:1234
0x0000000000001000 in ?? ()
(gdb) b _start
Breakpoint 1 at 0x80000000: file /home/zrmin/opensbi/firmware/fw_base.S, line 50.
(gdb) c
Continuing.
Breakpoint 1, _start () at /home/zrmin/opensbi/firmware/fw_base.S:50
50 MOV_3R s0, a0, s1, a1, s2, a2
(gdb)
This is because QEMU loads OpenSBI at address 0x80000000. When
FW_TEXT_START does not match this address, the debug symbols are
incorrectly offset, causing GDB to fail to set breakpoints properly.
Signed-off-by: Zhang RunMin <runmin.zhang@ingenic.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260319125641.480161-1-runmin.zhang@ingenic.com
Signed-off-by: Anup Patel <anup@brainfault.org>
184 lines
4.4 KiB
Markdown
184 lines
4.4 KiB
Markdown
QEMU RISC-V Virt Machine Platform
|
|
=================================
|
|
|
|
The **QEMU RISC-V Virt Machine** is a virtual platform created for RISC-V
|
|
software development and testing. It is also referred to as
|
|
*QEMU RISC-V VirtIO machine* because it uses VirtIO devices for network,
|
|
storage, and other types of IO.
|
|
|
|
To build the platform-specific library and firmware images, provide the
|
|
*PLATFORM=generic* parameter to the top level `make` command.
|
|
|
|
Platform Options
|
|
----------------
|
|
|
|
The *QEMU RISC-V Virt Machine* platform does not have any platform-specific
|
|
options.
|
|
|
|
Execution on QEMU RISC-V 64-bit
|
|
-------------------------------
|
|
|
|
**No Payload Case**
|
|
|
|
Build:
|
|
```
|
|
make PLATFORM=generic
|
|
```
|
|
|
|
Run:
|
|
```
|
|
qemu-system-riscv64 -M virt -m 256M -nographic \
|
|
-bios build/platform/generic/firmware/fw_payload.bin
|
|
```
|
|
|
|
**U-Boot Payload**
|
|
|
|
Note: the command line examples here assume that U-Boot was compiled using
|
|
the `qemu-riscv64_smode_defconfig` configuration.
|
|
|
|
Build:
|
|
```
|
|
make PLATFORM=generic FW_PAYLOAD_PATH=<uboot_build_directory>/u-boot.bin
|
|
```
|
|
|
|
Run:
|
|
```
|
|
qemu-system-riscv64 -M virt -m 256M -nographic \
|
|
-bios build/platform/generic/firmware/fw_payload.elf
|
|
```
|
|
or
|
|
```
|
|
qemu-system-riscv64 -M virt -m 256M -nographic \
|
|
-bios build/platform/generic/firmware/fw_jump.bin \
|
|
-kernel <uboot_build_directory>/u-boot.bin
|
|
```
|
|
|
|
**Linux Kernel Payload**
|
|
|
|
Note: We assume that the Linux kernel is compiled using
|
|
*arch/riscv/configs/defconfig*. The kernel must be a flattened image (a file
|
|
called `Image`) rather than an ELF (`vmlinux`).
|
|
|
|
Example of building a Linux kernel:
|
|
```
|
|
make ARCH=riscv CROSS_COMPILE=riscv64-linux- defconfig
|
|
make ARCH=riscv CROSS_COMPILE=riscv64-linux- Image
|
|
```
|
|
|
|
Build:
|
|
```
|
|
make PLATFORM=generic FW_PAYLOAD_PATH=<linux_build_directory>/arch/riscv/boot/Image
|
|
```
|
|
|
|
Run:
|
|
```
|
|
qemu-system-riscv64 -M virt -m 256M -nographic \
|
|
-bios build/platform/generic/firmware/fw_payload.elf \
|
|
-drive file=<path_to_linux_rootfs>,format=raw,id=hd0 \
|
|
-device virtio-blk-device,drive=hd0 \
|
|
-append "root=/dev/vda rw console=ttyS0"
|
|
```
|
|
or
|
|
```
|
|
qemu-system-riscv64 -M virt -m 256M -nographic \
|
|
-bios build/platform/generic/firmware/fw_jump.bin \
|
|
-kernel <linux_build_directory>/arch/riscv/boot/Image \
|
|
-drive file=<path_to_linux_rootfs>,format=raw,id=hd0 \
|
|
-device virtio-blk-device,drive=hd0 \
|
|
-append "root=/dev/vda rw console=ttyS0"
|
|
```
|
|
|
|
|
|
Execution on QEMU RISC-V 32-bit
|
|
-------------------------------
|
|
|
|
**No Payload Case**
|
|
|
|
Build:
|
|
```
|
|
make PLATFORM=generic PLATFORM_RISCV_XLEN=32
|
|
```
|
|
|
|
Run:
|
|
```
|
|
qemu-system-riscv32 -M virt -m 256M -nographic \
|
|
-bios build/platform/generic/firmware/fw_payload.bin
|
|
```
|
|
|
|
**U-Boot Payload**
|
|
|
|
Note: the command line examples here assume that U-Boot was compiled using
|
|
the `qemu-riscv32_smode_defconfig` configuration.
|
|
|
|
Build:
|
|
```
|
|
make PLATFORM=generic PLATFORM_RISCV_XLEN=32 FW_PAYLOAD_PATH=<uboot_build_directory>/u-boot.bin
|
|
```
|
|
|
|
Run:
|
|
```
|
|
qemu-system-riscv32 -M virt -m 256M -nographic \
|
|
-bios build/platform/generic/firmware/fw_payload.elf
|
|
```
|
|
or
|
|
```
|
|
qemu-system-riscv32 -M virt -m 256M -nographic \
|
|
-bios build/platform/generic/firmware/fw_jump.bin \
|
|
-kernel <uboot_build_directory>/u-boot.bin
|
|
```
|
|
|
|
**Linux Kernel Payload**
|
|
|
|
Note: We assume that the Linux kernel is compiled using
|
|
*arch/riscv/configs/rv32_defconfig*.
|
|
|
|
Build:
|
|
```
|
|
make PLATFORM=generic PLATFORM_RISCV_XLEN=32 FW_PAYLOAD_PATH=<linux_build_directory>/arch/riscv/boot/Image
|
|
```
|
|
|
|
Run:
|
|
```
|
|
qemu-system-riscv32 -M virt -m 256M -nographic \
|
|
-bios build/platform/generic/firmware/fw_payload.elf \
|
|
-drive file=<path_to_linux_rootfs>,format=raw,id=hd0 \
|
|
-device virtio-blk-device,drive=hd0 \
|
|
-append "root=/dev/vda rw console=ttyS0"
|
|
```
|
|
or
|
|
```
|
|
qemu-system-riscv32 -M virt -m 256M -nographic \
|
|
-bios build/platform/generic/firmware/fw_jump.bin \
|
|
-kernel <linux_build_directory>/arch/riscv/boot/Image \
|
|
-drive file=<path_to_linux_rootfs>,format=raw,id=hd0 \
|
|
-device virtio-blk-device,drive=hd0 \
|
|
-append "root=/dev/vda rw console=ttyS0"
|
|
```
|
|
|
|
Debugging with GDB
|
|
------------------
|
|
|
|
Note: the command line examples here assume that OpenSBI was compiled using
|
|
the `DEBUG=1 FW_TEXT_START=0x80000000` configuration.
|
|
|
|
In a first console start OpenSBI with QEMU:
|
|
|
|
```
|
|
qemu-system-riscv64 -M virt -m 256M -nographic \
|
|
-bios build/platform/generic/firmware/fw_payload.bin \
|
|
-gdb tcp::1234 \
|
|
-S
|
|
|
|
```
|
|
|
|
Parameter *-gdb tcp::1234* specifies 1234 as the debug port.
|
|
Parameter *-S* lets QEMU wait at the first instruction.
|
|
|
|
In a second console start GDB:
|
|
|
|
```
|
|
gdb build/platform/generic/firmware/fw_payload.elf \
|
|
-ex 'target remote localhost:1234'
|
|
|
|
```
|