The current implementation of make_chosen_node() does not contain any
architecture-specific logic. Therefore, move it from arch-specific
files to common code.

At this stage, there is no need to introduce an arch_make_chosen_node(),
as no architecture-specific customization is required.

This change avoids duplication and simplifies future maintenance for
architectures like RISC-V and ARM.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
 xen/arch/arm/domain_build.c             | 46 -------------------------
 xen/common/device-tree/dom0less-build.c | 46 +++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 46 deletions(-)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index b189a7cfae..9e71cc8cef 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1470,52 +1470,6 @@ int __init make_timer_node(const struct kernel_info *kinfo)
     return res;
 }
 
-/*
- * This function is used as part of the device tree generation for Dom0
- * on ACPI systems, and DomUs started directly from Xen based on device
- * tree information.
- */
-int __init make_chosen_node(const struct kernel_info *kinfo)
-{
-    int res;
-    const char *bootargs = NULL;
-    const struct bootmodule *initrd = kinfo->initrd_bootmodule;
-    void *fdt = kinfo->fdt;
-
-    dt_dprintk("Create chosen node\n");
-    res = fdt_begin_node(fdt, "chosen");
-    if ( res )
-        return res;
-
-    if ( kinfo->cmdline && kinfo->cmdline[0] )
-    {
-        bootargs = &kinfo->cmdline[0];
-        res = fdt_property(fdt, "bootargs", bootargs, strlen(bootargs) + 1);
-        if ( res )
-           return res;
-    }
-
-    /*
-     * If the bootloader provides an initrd, we must create a placeholder
-     * for the initrd properties. The values will be replaced later.
-     */
-    if ( initrd && initrd->size )
-    {
-        u64 a = 0;
-        res = fdt_property(kinfo->fdt, "linux,initrd-start", &a, sizeof(a));
-        if ( res )
-            return res;
-
-        res = fdt_property(kinfo->fdt, "linux,initrd-end", &a, sizeof(a));
-        if ( res )
-            return res;
-    }
-
-    res = fdt_end_node(fdt);
-
-    return res;
-}
-
 static int __init handle_node(struct domain *d, struct kernel_info *kinfo,
                               struct dt_device_node *node,
                               p2m_type_t p2mt)
diff --git a/xen/common/device-tree/dom0less-build.c b/xen/common/device-tree/dom0less-build.c
index f6aabc2093..1265cadf94 100644
--- a/xen/common/device-tree/dom0less-build.c
+++ b/xen/common/device-tree/dom0less-build.c
@@ -434,6 +434,52 @@ static int __init domain_handle_dtb_bootmodule(struct domain *d,
     return res;
 }
 
+/*
+ * This function is used as part of the device tree generation for Dom0
+ * on ACPI systems, and DomUs started directly from Xen based on device
+ * tree information.
+ */
+int __init make_chosen_node(const struct kernel_info *kinfo)
+{
+    int res;
+    const char *bootargs = NULL;
+    const struct bootmodule *initrd = kinfo->initrd_bootmodule;
+    void *fdt = kinfo->fdt;
+
+    dt_dprintk("Create chosen node\n");
+    res = fdt_begin_node(fdt, "chosen");
+    if ( res )
+        return res;
+
+    if ( kinfo->cmdline && kinfo->cmdline[0] )
+    {
+        bootargs = &kinfo->cmdline[0];
+        res = fdt_property(fdt, "bootargs", bootargs, strlen(bootargs) + 1);
+        if ( res )
+           return res;
+    }
+
+    /*
+     * If the bootloader provides an initrd, we must create a placeholder
+     * for the initrd properties. The values will be replaced later.
+     */
+    if ( initrd && initrd->size )
+    {
+        u64 a = 0;
+        res = fdt_property(kinfo->fdt, "linux,initrd-start", &a, sizeof(a));
+        if ( res )
+            return res;
+
+        res = fdt_property(kinfo->fdt, "linux,initrd-end", &a, sizeof(a));
+        if ( res )
+            return res;
+    }
+
+    res = fdt_end_node(fdt);
+
+    return res;
+}
+
 /*
  * The max size for DT is 2MB. However, the generated DT is small (not including
  * domU passthrough DT nodes whose size we account separately), 4KB are enough
-- 
2.49.0

On 13/05/2025 16:29, Oleksii Kurochko wrote:
> The current implementation of make_chosen_node() does not contain any
> architecture-specific logic. Therefore, move it from arch-specific
> files to common code.
> 
> At this stage, there is no need to introduce an arch_make_chosen_node(),
> as no architecture-specific customization is required.
> 
> This change avoids duplication and simplifies future maintenance for
> architectures like RISC-V and ARM.
> 
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>

[snip]

> +/*
> + * This function is used as part of the device tree generation for Dom0
> + * on ACPI systems, and DomUs started directly from Xen based on device
Might be worth adding (on Arm) after 'ACPI systems'. Could be done on commit.

~Michal

Hi Michal,

On 13/05/2025 15:45, Orzel, Michal wrote:
> 
> 
> On 13/05/2025 16:29, Oleksii Kurochko wrote:
>> The current implementation of make_chosen_node() does not contain any
>> architecture-specific logic. Therefore, move it from arch-specific
>> files to common code.
>>
>> At this stage, there is no need to introduce an arch_make_chosen_node(),
>> as no architecture-specific customization is required.
>>
>> This change avoids duplication and simplifies future maintenance for
>> architectures like RISC-V and ARM.
>>
>> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
> Reviewed-by: Michal Orzel <michal.orzel@amd.com>
> 
> [snip]
> 
>> +/*
>> + * This function is used as part of the device tree generation for Dom0
>> + * on ACPI systems, and DomUs started directly from Xen based on device
> Might be worth adding (on Arm) after 'ACPI systems'. Could be done on commit.

Please don't. This will become stale otherwise as soon as RISC-V is 
started to use it. Instead, we should say (on platform where CONFIG_ACPI=y).

Cheers,

-- 
Julien Grall