Re: [U-Boot] [PATCH v2 28/29] riscv: qemu: detect and boot the kernel passed by QEMU

Hi Bin,

On Sun, 2018-11-04 at 22:39 +0800, Bin Meng wrote:

Hi Lukas,

On Tue, Oct 30, 2018 at 8:57 PM Lukas Auer lukas.auer@aisec.fraunhofer.de wrote:

...

QEMU embeds the location of the kernel image in the device tree. Store this address in the environment as variable kernel_start and use it in CONFIG_BOOTCOMMAND to boot the kernel. Use the device tree passed by the prior boot stage to boot Linux.

Signed-off-by: Lukas Auer lukas.auer@aisec.fraunhofer.de

Changes in v2:

• Rebase onto u-boot-dm/next
• Boot Linux with the device tree provided by the prior boot stage

board/emulation/qemu-riscv/Kconfig | 1 + board/emulation/qemu-riscv/qemu-riscv.c | 29 +++++++++++++++++++++++++ configs/qemu-riscv32_defconfig | 1 + configs/qemu-riscv64_defconfig | 1 + include/configs/qemu-riscv.h | 10 ++++++++- 5 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/board/emulation/qemu-riscv/Kconfig b/board/emulation/qemu-riscv/Kconfig index 37a80db6a9..be5839b7db 100644 --- a/board/emulation/qemu-riscv/Kconfig +++ b/board/emulation/qemu-riscv/Kconfig @@ -29,5 +29,6 @@ config BOARD_SPECIFIC_OPTIONS # dummy imply CMD_EXT2 imply CMD_EXT4 imply CMD_FAT

•   imply BOARD_LATE_INIT
  
  

endif diff --git a/board/emulation/qemu-riscv/qemu-riscv.c b/board/emulation/qemu-riscv/qemu-riscv.c index 2ce093e19a..ee20983095 100644 --- a/board/emulation/qemu-riscv/qemu-riscv.c +++ b/board/emulation/qemu-riscv/qemu-riscv.c @@ -19,3 +19,32 @@ int board_init(void)

    return 0;

}

+int board_late_init(void) +{

•   ulong kernel_start;
  

•   ofnode chosen_node;
  

•   int ret;
  

•   chosen_node = ofnode_path("/chosen");
  

•   if (!ofnode_valid(chosen_node)) {
  

•           printf("No chosen node found\n");
  

•           return 0;
  

•   }
  

+#ifdef CONFIG_ARCH_RV64I

•   ret = ofnode_read_u64(chosen_node, "riscv,kernel-start",
  

•                         (u64 *)&kernel_start);
  

+#else

•   ret = ofnode_read_u32(chosen_node, "riscv,kernel-start",
  

•                         (u32 *)&kernel_start);
  

+#endif

•   if (ret) {
  

•           printf("Can't find kernel start address in device
  

tree\n");

I think we need use 'debug' instead of 'printf' here, for situation that kernel is not passed to QEMU.

Yes, you are right. What is the current best-practice here? Should I use one of the pr_* functions or just debug?

Looking at the function, I am also not sure how useful the printf above is (no chosen node found). I could replace it with the same text as in the last printf. What do you think?

Thanks, Lukas

...

•           return 0;
  

•   }
  

•   env_set_hex("kernel_start", kernel_start);
  

•   return 0;
  

+}

[snip]

Regards, Bin