2023-12-05 09:55:55

by Yoshinori Sato

Subject: [DO NOT MERGE v5 06/37] sh: kernel/setup Update DT support.

Fix extrnal fdt initialize and bootargs.

Signed-off-by: Yoshinori Sato <[email protected]>
---
arch/sh/kernel/setup.c | 51 ++++++++++++++++++++++++++++--------------
1 file changed, 34 insertions(+), 17 deletions(-)

diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index 3d80515298d2..b299abff68e0 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -30,6 +30,7 @@
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
#include <linux/uaccess.h>
#include <uapi/linux/mount.h>
#include <asm/io.h>
@@ -74,7 +75,13 @@ extern int root_mountflags;
#define RAMDISK_PROMPT_FLAG 0x8000
#define RAMDISK_LOAD_FLAG 0x4000

+#if defined(CONFIG_OF) && !defined(CONFIG_USE_BUILTIN_DTB)
+#define CHOSEN_BOOTARGS
+#endif
+
+#ifndef CHOSEN_BOOTARGS
static char __initdata command_line[COMMAND_LINE_SIZE] = { 0, };
+#endif

static struct resource code_resource = {
.name = "Kernel code",
@@ -244,18 +251,18 @@ void __init __weak plat_early_device_setup(void)
void __ref sh_fdt_init(phys_addr_t dt_phys)
{
static int done = 0;
- void *dt_virt;
+ void *fdt;

/* Avoid calling an __init function on secondary cpus. */
if (done) return;

#ifdef CONFIG_USE_BUILTIN_DTB
- dt_virt = __dtb_start;
+ fdt = __dtb_start;
#else
- dt_virt = phys_to_virt(dt_phys);
+ fdt = phys_to_virt(dt_phys);
#endif

- if (!dt_virt || !early_init_dt_scan(dt_virt)) {
+ if (!fdt || !early_init_dt_scan(fdt)) {
pr_crit("Error: invalid device tree blob"
" at physical address %p\n", (void *)dt_phys);

@@ -269,8 +276,20 @@ void __ref sh_fdt_init(phys_addr_t dt_phys)

void __init setup_arch(char **cmdline_p)
{
+#ifdef CONFIG_OF_EARLY_FLATTREE
+ if (IS_ENABLED(CONFIG_USE_BUILTIN_DTB)) {
+ /* Relocate Embedded DTB */
+ unflatten_and_copy_device_tree();
+ } else if (initial_boot_params) {
+ /* Reserve external DTB area */
+ memblock_reserve(__pa(initial_boot_params),
+ fdt_totalsize(initial_boot_params));
+ unflatten_device_tree();
+ }
+#endif
enable_mmu();

+#ifndef CONFIG_OF
ROOT_DEV = old_decode_dev(ORIG_ROOT_DEV);

printk(KERN_NOTICE "Boot params:\n"
@@ -299,19 +318,25 @@ void __init setup_arch(char **cmdline_p)
bss_resource.start = virt_to_phys(__bss_start);
bss_resource.end = virt_to_phys(__bss_stop)-1;

-#ifdef CONFIG_CMDLINE_OVERWRITE
- strscpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
-#else
+#endif
+
+#ifndef CHOSEN_BOOTARGS
+#ifndef CONFIG_CMDLINE_OVERWRITE
strscpy(command_line, COMMAND_LINE, sizeof(command_line));
#ifdef CONFIG_CMDLINE_EXTEND
strlcat(command_line, " ", sizeof(command_line));
strlcat(command_line, CONFIG_CMDLINE, sizeof(command_line));
#endif
-#endif
-
+#else /* !CONFIG_CMDLINE_OVERWRITE*/
+ strscpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
+#endif /* CONFIG_CMDLINE_OVERWRITE */
/* Save unparsed command line copy for /proc/cmdline */
memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
+#else /* CHOSEN_BOOTARGS */
+ /* Use "/chosen/bootargs" specified in devicetree. */
+ *cmdline_p = boot_command_line;
+#endif

parse_early_param();

@@ -322,14 +347,6 @@ void __init setup_arch(char **cmdline_p)
/* Let earlyprintk output early console messages */
sh_early_platform_driver_probe("earlyprintk", 1, 1);

-#ifdef CONFIG_OF_EARLY_FLATTREE
-#ifdef CONFIG_USE_BUILTIN_DTB
- unflatten_and_copy_device_tree();
-#else
- unflatten_device_tree();
-#endif
-#endif
-
paging_init();

/* Perform the machine specific initialisation */
--
2.39.2

2023-12-06 08:40:30

by Arnd Bergmann

Subject: Re: [DO NOT MERGE v5 06/37] sh: kernel/setup Update DT support.

On Tue, Dec 5, 2023, at 10:45, Yoshinori Sato wrote:
> Fix extrnal fdt initialize and bootargs.
>
> Signed-off-by: Yoshinori Sato <[email protected]>
> ---
> arch/sh/kernel/setup.c | 51 ++++++++++++++++++++++++++++--------------
> 1 file changed, 34 insertions(+), 17 deletions(-)
>
> diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
> index 3d80515298d2..b299abff68e0 100644
> --- a/arch/sh/kernel/setup.c
> +++ b/arch/sh/kernel/setup.c
> @@ -30,6 +30,7 @@
> #include <linux/memblock.h>
> #include <linux/of.h>
> #include <linux/of_fdt.h>
> +#include <linux/libfdt.h>
> #include <linux/uaccess.h>
> #include <uapi/linux/mount.h>
> #include <asm/io.h>
> @@ -74,7 +75,13 @@ extern int root_mountflags;
> #define RAMDISK_PROMPT_FLAG 0x8000
> #define RAMDISK_LOAD_FLAG 0x4000
>
> +#if defined(CONFIG_OF) && !defined(CONFIG_USE_BUILTIN_DTB)
> +#define CHOSEN_BOOTARGS
> +#endif
> +
> +#ifndef CHOSEN_BOOTARGS
> static char __initdata command_line[COMMAND_LINE_SIZE] = { 0, };
> +#endif

I think an appended DTB is generally better than a built-in
one, as that allows you to still have a single kernel
image across machines and just pick the dtb when installing it.

With everything else being equal, I would suggest not
actually making this an option for new platforms.

Arnd