Real-time kernels such as RTEMS or Zephyr may use a static device tree
built into the kernel image. Do not require to use the -dtb option if
-kernel is used for the microchip-icicle-kit machine. Issue a warning
if no device tree is provided by the user since the machine does not
generate one.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
---
hw/riscv/microchip_pfsoc.c | 56 +++++++++++++++++++-------------------
1 file changed, 28 insertions(+), 28 deletions(-)
diff --git a/hw/riscv/microchip_pfsoc.c b/hw/riscv/microchip_pfsoc.c
index f477d2791e..844dc0545c 100644
--- a/hw/riscv/microchip_pfsoc.c
+++ b/hw/riscv/microchip_pfsoc.c
@@ -516,7 +516,6 @@ static void microchip_icicle_kit_machine_init(MachineState *machine)
uint64_t mem_low_size, mem_high_size;
hwaddr firmware_load_addr;
const char *firmware_name;
- bool kernel_as_payload = false;
target_ulong firmware_end_addr, kernel_start_addr;
uint64_t kernel_entry;
uint64_t fdt_load_addr;
@@ -589,25 +588,12 @@ static void microchip_icicle_kit_machine_init(MachineState *machine)
*
* This ensures backwards compatibility with how we used to expose -bios
* to users but allows them to run through direct kernel booting as well.
- *
- * When -kernel is used for direct boot, -dtb must be present to provide
- * a valid device tree for the board, as we don't generate device tree.
*/
- if (machine->kernel_filename && machine->dtb) {
- int fdt_size;
- machine->fdt = load_device_tree(machine->dtb, &fdt_size);
- if (!machine->fdt) {
- error_report("load_device_tree() failed");
- exit(1);
- }
-
+ if (machine->kernel_filename) {
firmware_name = RISCV64_BIOS_BIN;
firmware_load_addr = memmap[MICROCHIP_PFSOC_DRAM_LO].base;
- kernel_as_payload = true;
- }
-
- if (!kernel_as_payload) {
+ } else {
firmware_name = BIOS_FILENAME;
firmware_load_addr = RESET_VECTOR;
}
@@ -617,7 +603,7 @@ static void microchip_icicle_kit_machine_init(MachineState *machine)
&firmware_load_addr, NULL);
riscv_boot_info_init(&boot_info, &s->soc.u_cpus);
- if (kernel_as_payload) {
+ if (machine->kernel_filename) {
kernel_start_addr = riscv_calc_kernel_start_addr(&boot_info,
firmware_end_addr);
@@ -625,19 +611,33 @@ static void microchip_icicle_kit_machine_init(MachineState *machine)
true, NULL);
kernel_entry = boot_info.image_low_addr;
- /* Compute the fdt load address in dram */
- hwaddr kernel_ram_base = memmap[MICROCHIP_PFSOC_DRAM_LO].base;
- hwaddr kernel_ram_size = memmap[MICROCHIP_PFSOC_DRAM_LO].size;
-
- if (kernel_entry - kernel_ram_base >= kernel_ram_size) {
- kernel_ram_base = memmap[MICROCHIP_PFSOC_DRAM_HI].base;
- kernel_ram_size = mem_high_size;
+ if (machine->dtb) {
+ int fdt_size;
+ machine->fdt = load_device_tree(machine->dtb, &fdt_size);
+ if (!machine->fdt) {
+ error_report("load_device_tree() failed");
+ exit(1);
+ }
+
+ /* Compute the FDT load address in DRAM */
+ hwaddr kernel_ram_base = memmap[MICROCHIP_PFSOC_DRAM_LO].base;
+ hwaddr kernel_ram_size = memmap[MICROCHIP_PFSOC_DRAM_LO].size;
+
+ if (kernel_entry - kernel_ram_base >= kernel_ram_size) {
+ kernel_ram_base = memmap[MICROCHIP_PFSOC_DRAM_HI].base;
+ kernel_ram_size = mem_high_size;
+ }
+
+ fdt_load_addr = riscv_compute_fdt_addr(kernel_ram_base, kernel_ram_size,
+ machine, &boot_info);
+ riscv_load_fdt(fdt_load_addr, machine->fdt);
+ } else {
+ warn_report_once("The QEMU microchip-icicle-kit machine does not "
+ "generate a device tree, so no device tree is "
+ "being provided to the guest.");
+ fdt_load_addr = 0;
}
- fdt_load_addr = riscv_compute_fdt_addr(kernel_ram_base, kernel_ram_size,
- machine, &boot_info);
- riscv_load_fdt(fdt_load_addr, machine->fdt);
-
/* Load the reset vector */
riscv_setup_rom_reset_vec(machine, &s->soc.u_cpus, firmware_load_addr,
memmap[MICROCHIP_PFSOC_ENVM_DATA].base,
--
2.43.0Hi, On Wed, Mar 19, 2025 at 07:13:35AM +0100, Sebastian Huber wrote: > Real-time kernels such as RTEMS or Zephyr may use a static device tree > built into the kernel image. Do not require to use the -dtb option if > -kernel is used for the microchip-icicle-kit machine. Issue a warning > if no device tree is provided by the user since the machine does not > generate one. > > Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de> > Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Starting with qemu v10.1.0, the command line is no longer passed to the kernel when booting Linux on the Icicle machine. Looking into the patch, the reason is quite obvious: The /chosen property is set in riscv_load_kernel(), which is now called before the devicetree is loaded. I was unable to find a clean solution other than reverting this and the next patch of the series, so this is just to let people know about the problem. Guenter
Hello Guenter, thanks for the report. Do you have a Linux image and a Qemu command line so that I can test this? -- embedded brains GmbH & Co. KG Herr Sebastian HUBER Dornierstr. 4 82178 Puchheim Germany email: sebastian.huber@embedded-brains.de phone: +49-89-18 94 741 - 16 fax: +49-89-18 94 741 - 08 Registergericht: Amtsgericht München Registernummer: HRB 157899 Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler Unsere Datenschutzerklärung finden Sie hier: https://embedded-brains.de/datenschutzerklaerung/
On 10/5/25 22:14, Sebastian Huber wrote: > Hello Guenter, > > thanks for the report. Do you have a Linux image and a Qemu command line so that I can test this? > See http://server.roeck-us.net/qemu/riscv64/ run.sh executed with qemu 10.1 or later should trigger the problem (the command line is not passed to the kernel). Guenter
On Tue, Oct 7, 2025 at 6:34 AM Guenter Roeck <linux@roeck-us.net> wrote: > > On 10/5/25 22:14, Sebastian Huber wrote: > > Hello Guenter, > > > > thanks for the report. Do you have a Linux image and a Qemu command line so that I can test this? > > > See http://server.roeck-us.net/qemu/riscv64/ > > run.sh executed with qemu 10.1 or later should trigger the problem > (the command line is not passed to the kernel). Any updates here? Alistair > > Guenter > >
----- Am 31. Okt 2025 um 3:56 schrieb Alistair Francis alistair23@gmail.com: > On Tue, Oct 7, 2025 at 6:34 AM Guenter Roeck <linux@roeck-us.net> wrote: >> >> On 10/5/25 22:14, Sebastian Huber wrote: >> > Hello Guenter, >> > >> > thanks for the report. Do you have a Linux image and a Qemu command line so that >> > I can test this? >> > >> See http://server.roeck-us.net/qemu/riscv64/ >> >> run.sh executed with qemu 10.1 or later should trigger the problem >> (the command line is not passed to the kernel). > > Any updates here? Sorry, I didn't forget it, but I have a huge backlog of work. -- embedded brains GmbH & Co. KG Herr Sebastian HUBER Dornierstr. 4 82178 Puchheim Germany email: sebastian.huber@embedded-brains.de phone: +49-89-18 94 741 - 16 fax: +49-89-18 94 741 - 08 Registergericht: Amtsgericht München Registernummer: HRB 157899 Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler Unsere Datenschutzerklärung finden Sie hier: https://embedded-brains.de/datenschutzerklaerung/
On 10/31/25 00:58, Sebastian Huber wrote: > ----- Am 31. Okt 2025 um 3:56 schrieb Alistair Francis alistair23@gmail.com: > >> On Tue, Oct 7, 2025 at 6:34 AM Guenter Roeck <linux@roeck-us.net> wrote: >>> >>> On 10/5/25 22:14, Sebastian Huber wrote: >>>> Hello Guenter, >>>> >>>> thanks for the report. Do you have a Linux image and a Qemu command line so that >>>> I can test this? >>>> >>> See http://server.roeck-us.net/qemu/riscv64/ >>> >>> run.sh executed with qemu 10.1 or later should trigger the problem >>> (the command line is not passed to the kernel). >> >> Any updates here? > > Sorry, I didn't forget it, but I have a huge backlog of work. > Has anyone else reported the problem ? If not, maybe everyone else is happy with the current behavior. If so, maybe documenting it is sufficient. No need to change for me, I can just carry the revert locally. Thanks, Guenter
On Wed, Mar 19, 2025 at 4:13 PM Sebastian Huber
<sebastian.huber@embedded-brains.de> wrote:
>
> Real-time kernels such as RTEMS or Zephyr may use a static device tree
> built into the kernel image. Do not require to use the -dtb option if
> -kernel is used for the microchip-icicle-kit machine. Issue a warning
> if no device tree is provided by the user since the machine does not
> generate one.
>
> Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Alistair
> ---
> hw/riscv/microchip_pfsoc.c | 56 +++++++++++++++++++-------------------
> 1 file changed, 28 insertions(+), 28 deletions(-)
>
> diff --git a/hw/riscv/microchip_pfsoc.c b/hw/riscv/microchip_pfsoc.c
> index f477d2791e..844dc0545c 100644
> --- a/hw/riscv/microchip_pfsoc.c
> +++ b/hw/riscv/microchip_pfsoc.c
> @@ -516,7 +516,6 @@ static void microchip_icicle_kit_machine_init(MachineState *machine)
> uint64_t mem_low_size, mem_high_size;
> hwaddr firmware_load_addr;
> const char *firmware_name;
> - bool kernel_as_payload = false;
> target_ulong firmware_end_addr, kernel_start_addr;
> uint64_t kernel_entry;
> uint64_t fdt_load_addr;
> @@ -589,25 +588,12 @@ static void microchip_icicle_kit_machine_init(MachineState *machine)
> *
> * This ensures backwards compatibility with how we used to expose -bios
> * to users but allows them to run through direct kernel booting as well.
> - *
> - * When -kernel is used for direct boot, -dtb must be present to provide
> - * a valid device tree for the board, as we don't generate device tree.
> */
>
> - if (machine->kernel_filename && machine->dtb) {
> - int fdt_size;
> - machine->fdt = load_device_tree(machine->dtb, &fdt_size);
> - if (!machine->fdt) {
> - error_report("load_device_tree() failed");
> - exit(1);
> - }
> -
> + if (machine->kernel_filename) {
> firmware_name = RISCV64_BIOS_BIN;
> firmware_load_addr = memmap[MICROCHIP_PFSOC_DRAM_LO].base;
> - kernel_as_payload = true;
> - }
> -
> - if (!kernel_as_payload) {
> + } else {
> firmware_name = BIOS_FILENAME;
> firmware_load_addr = RESET_VECTOR;
> }
> @@ -617,7 +603,7 @@ static void microchip_icicle_kit_machine_init(MachineState *machine)
> &firmware_load_addr, NULL);
>
> riscv_boot_info_init(&boot_info, &s->soc.u_cpus);
> - if (kernel_as_payload) {
> + if (machine->kernel_filename) {
> kernel_start_addr = riscv_calc_kernel_start_addr(&boot_info,
> firmware_end_addr);
>
> @@ -625,19 +611,33 @@ static void microchip_icicle_kit_machine_init(MachineState *machine)
> true, NULL);
> kernel_entry = boot_info.image_low_addr;
>
> - /* Compute the fdt load address in dram */
> - hwaddr kernel_ram_base = memmap[MICROCHIP_PFSOC_DRAM_LO].base;
> - hwaddr kernel_ram_size = memmap[MICROCHIP_PFSOC_DRAM_LO].size;
> -
> - if (kernel_entry - kernel_ram_base >= kernel_ram_size) {
> - kernel_ram_base = memmap[MICROCHIP_PFSOC_DRAM_HI].base;
> - kernel_ram_size = mem_high_size;
> + if (machine->dtb) {
> + int fdt_size;
> + machine->fdt = load_device_tree(machine->dtb, &fdt_size);
> + if (!machine->fdt) {
> + error_report("load_device_tree() failed");
> + exit(1);
> + }
> +
> + /* Compute the FDT load address in DRAM */
> + hwaddr kernel_ram_base = memmap[MICROCHIP_PFSOC_DRAM_LO].base;
> + hwaddr kernel_ram_size = memmap[MICROCHIP_PFSOC_DRAM_LO].size;
> +
> + if (kernel_entry - kernel_ram_base >= kernel_ram_size) {
> + kernel_ram_base = memmap[MICROCHIP_PFSOC_DRAM_HI].base;
> + kernel_ram_size = mem_high_size;
> + }
> +
> + fdt_load_addr = riscv_compute_fdt_addr(kernel_ram_base, kernel_ram_size,
> + machine, &boot_info);
> + riscv_load_fdt(fdt_load_addr, machine->fdt);
> + } else {
> + warn_report_once("The QEMU microchip-icicle-kit machine does not "
> + "generate a device tree, so no device tree is "
> + "being provided to the guest.");
> + fdt_load_addr = 0;
> }
>
> - fdt_load_addr = riscv_compute_fdt_addr(kernel_ram_base, kernel_ram_size,
> - machine, &boot_info);
> - riscv_load_fdt(fdt_load_addr, machine->fdt);
> -
> /* Load the reset vector */
> riscv_setup_rom_reset_vec(machine, &s->soc.u_cpus, firmware_load_addr,
> memmap[MICROCHIP_PFSOC_ENVM_DATA].base,
> --
> 2.43.0
>
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