Re: [PATCH V3 3/3] hw/riscv: virt: Enable booting S-mode firmware from pflash

[Andrew Jones]

On Tue, Sep 06, 2022 at 09:54:51AM +0530, Sunil V L wrote:
> To boot S-mode firmware payload like EDK2 from persistent
> flash storage, qemu needs to pass the flash address as the
> next_addr in fw_dynamic_info to the opensbi.
> 
> When both -kernel and -pflash options are provided in command line,
> the kernel (and initrd if -initrd) will be copied to fw_cfg table.
> The S-mode FW will load the kernel/initrd from fw_cfg table.
> 
> If only pflash is given but not -kernel, then it is the job of
> of the S-mode firmware to locate and load the kernel.
> 
> In either case, update the kernel_entry with the flash address
> so that the opensbi can jump to the entry point of the S-mode
> firmware.
> 
> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> ---
>  hw/riscv/boot.c         | 28 ++++++++++++++++++++++++++++
>  hw/riscv/virt.c         | 17 ++++++++++++++++-
>  include/hw/riscv/boot.h |  1 +
>  3 files changed, 45 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
> index 1ae7596873..39436b8d56 100644
> --- a/hw/riscv/boot.c
> +++ b/hw/riscv/boot.c
> @@ -338,3 +338,31 @@ void riscv_setup_direct_kernel(hwaddr kernel_addr, 
> hwaddr fdt_addr)
>          riscv_cpu->env.fdt_addr = fdt_addr;
>      }
>  }
> +
> +void riscv_setup_firmware_boot(MachineState *machine)
> +{
> +    if (machine->kernel_filename) {
> +        FWCfgState *fw_cfg;
> +        fw_cfg = fw_cfg_find();
> +
> +        assert(fw_cfg);
> +        /*
> +         * Expose the kernel, the command line, and the initrd in fw_cfg.
> +         * We don't process them here at all, it's all left to the
> +         * firmware.
> +         */
> +        load_image_to_fw_cfg(fw_cfg,
> +                             FW_CFG_KERNEL_SIZE, FW_CFG_KERNEL_DATA,
> +                             machine->kernel_filename,
> +                             true);
> +        load_image_to_fw_cfg(fw_cfg,
> +                             FW_CFG_INITRD_SIZE, FW_CFG_INITRD_DATA,
> +                             machine->initrd_filename, false);

blank line

> +        if (machine->kernel_cmdline) {
> +            fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE,
> +                           strlen(machine->kernel_cmdline) + 1);
> +            fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA,
> +                              machine->kernel_cmdline);
> +        }
> +    }
> +}
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index b6bbf03f61..b985df9b16 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -1258,7 +1258,22 @@ static void virt_machine_done(Notifier *notifier, void 
> *data)
>      s->fw_cfg = create_fw_cfg(machine);
>      rom_set_fw(s->fw_cfg);
>  
> -    if (machine->kernel_filename) {
> +    if (drive_get(IF_PFLASH, 0, 1)) {
> +        /*
> +         * S-mode FW like EDk2 will be kept in second plash (unit 1). When

edk2 or EDK2

> +         * both -kernel and -pflash options are provided in command line,
                                                              ^ the
> +         * the kernel, initrd will be copied to fw_cfg table and opensbi
                        ^                         ^ the
                        ^ replace, with ' and'
                       
> +         * will jump to flash address which is the entry point of S-mode FW.
                          ^ the
> +         * It is the job of the S-mode FW to load the kernel/initrd and 
> launch.
> +         *
> +         * If only pflash is given but not -kernel, then it is the job of
> +         * of the S-mode firmware to locate and load the kernel.
> +         * In either case, the next_addr for opensbi will be the flash 
> address.
> +         */
> +        riscv_setup_firmware_boot(machine);
> +        kernel_entry = virt_memmap[VIRT_FLASH].base +
> +                         virt_memmap[VIRT_FLASH].size / 2;
                          ^
                          Please line up the lower virt_memmap[] with the upper

> +    } else if (machine->kernel_filename) {
>          kernel_start_addr = riscv_calc_kernel_start_addr(&s->soc[0],
>                                                           firmware_end_addr);
>  
> diff --git a/include/hw/riscv/boot.h b/include/hw/riscv/boot.h
> index a36f7618f5..93e5f8760d 100644
> --- a/include/hw/riscv/boot.h
> +++ b/include/hw/riscv/boot.h
> @@ -57,5 +57,6 @@ void riscv_rom_copy_firmware_info(MachineState *machine, 
> hwaddr rom_base,
>                                    uint32_t reset_vec_size,
>                                    uint64_t kernel_entry);
>  void riscv_setup_direct_kernel(hwaddr kernel_addr, hwaddr fdt_addr);
> +void riscv_setup_firmware_boot(MachineState *machine);
>  
>  #endif /* RISCV_BOOT_H */
> -- 
> 2.25.1
> 

Besides the whitespace and comment edits

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>

Thanks,
drew