Re: [PATCH 1/2] board_f: fix use of GD_FLG_SKIP_RELOC

Re: [PATCH 1/2] board_f: fix use of GD_FLG_SKIP_RELOC

[Marek Vasut]

On 10/13/21 11:54 AM, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> When dtb is padded in the end of U-Boot binary, dtb should always be
> relocated whether GD_FLG_SKIP_RELOC set or not, otherwise dtb
> maybe corrupted.
> 
> Need copy old gd contents to new_gd area, this may not needed on x86 or
> arc, but needed for ARM64, because crt0_64.S points x18 to new_gd,
> considering gd is a small area, and common/board_f.c also use new_gd,
> so let's always copy it.

Have a look at these patches:

https://patchwork.ozlabs.org/project/uboot/patch/20211010215209.872181-1-marek.vasut@gmail.com/
https://patchwork.ozlabs.org/project/uboot/patch/20211010215209.872181-2-marek.vasut@gmail.com/
https://patchwork.ozlabs.org/project/uboot/patch/20211010214410.870766-1-marek.vasut+renesas@gmail.com/

[PATCH 1/2] board_f: fix use of GD_FLG_SKIP_RELOC

[Peng Fan (OSS)]

From: Peng Fan <peng.fan@nxp.com>

When dtb is padded in the end of U-Boot binary, dtb should always be
relocated whether GD_FLG_SKIP_RELOC set or not, otherwise dtb
maybe corrupted.

Need copy old gd contents to new_gd area, this may not needed on x86 or
arc, but needed for ARM64, because crt0_64.S points x18 to new_gd,
considering gd is a small area, and common/board_f.c also use new_gd,
so let's always copy it.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 common/board_f.c                  | 8 ++++----
 include/asm-generic/global_data.h | 4 ++++
 lib/asm-offsets.c                 | 2 ++
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/common/board_f.c b/common/board_f.c
index 3dc0eaa59c..54a306df7d 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -621,13 +621,13 @@ static int init_post(void)
 static int reloc_fdt(void)
 {
 	if (!IS_ENABLED(CONFIG_OF_EMBED)) {
-		if (gd->flags & GD_FLG_SKIP_RELOC)
-			return 0;
 		if (gd->new_fdt) {
 			memcpy(gd->new_fdt, gd->fdt_blob,
 			       fdt_totalsize(gd->fdt_blob));
 			gd->fdt_blob = gd->new_fdt;
 		}
+		if (gd->flags & GD_FLG_SKIP_RELOC)
+			return 0;
 	}
 
 	return 0;
@@ -673,6 +673,8 @@ static int reloc_bloblist(void)
 
 static int setup_reloc(void)
 {
+	memcpy(gd->new_gd, (char *)gd, sizeof(gd_t));
+
 	if (gd->flags & GD_FLG_SKIP_RELOC) {
 		debug("Skipping relocation due to flag\n");
 		return 0;
@@ -691,8 +693,6 @@ static int setup_reloc(void)
 	gd->reloc_off = gd->relocaddr - CONFIG_SYS_TEXT_BASE;
 #endif
 #endif
-	memcpy(gd->new_gd, (char *)gd, sizeof(gd_t));
-
 	debug("Relocation Offset is: %08lx\n", gd->reloc_off);
 	debug("Relocating to %08lx, new gd at %08lx, sp at %08lx\n",
 	      gd->relocaddr, (ulong)map_to_sysmem(gd->new_gd),
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 16fd305a65..4a3f8be047 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -600,6 +600,10 @@ enum gd_flags {
 	GD_FLG_SMP_READY = 0x80000,
 };
 
+#else
+
+#define GD_FLG_SKIP_RELOC	0x00800
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __ASM_GENERIC_GBL_DATA_H */
diff --git a/lib/asm-offsets.c b/lib/asm-offsets.c
index c691066332..de130574cd 100644
--- a/lib/asm-offsets.c
+++ b/lib/asm-offsets.c
@@ -43,5 +43,7 @@ int main(void)
 
 	DEFINE(GD_ENV_ADDR, offsetof(struct global_data, env_addr));
 
+	DEFINE(GD_FLAGS, offsetof(struct global_data, flags));
+
 	return 0;
 }
-- 
2.30.0

[PATCH 2/2] arm: crt0_64: support skip u-boot relocation

[Peng Fan (OSS)]

From: Peng Fan <peng.fan@nxp.com>

U-Boot binary is quite large with more options enabled, it not hurt
on real silicon with high performance. But on simulation platform,
it is quite slow to relocate the U-Boot binary to new address,
so let's support skipping relocation.

Users could use 'gd->flags |= GD_FLG_SKIP_RELOC;' in board_early_init_f
or other place that early than relocate_code.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 arch/arm/lib/crt0_64.S | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/lib/crt0_64.S b/arch/arm/lib/crt0_64.S
index 680e674fa3..d57ca84ee4 100644
--- a/arch/arm/lib/crt0_64.S
+++ b/arch/arm/lib/crt0_64.S
@@ -12,6 +12,7 @@
 #include <config.h>
 #include <asm-offsets.h>
 #include <asm/macro.h>
+#include <asm-generic/global_data.h>
 #include <linux/linkage.h>
 
 /*
@@ -95,6 +96,7 @@ ENTRY(_main)
 	bl	board_init_f
 
 #if !defined(CONFIG_SPL_BUILD)
+	ldr	x1, [x18, #GD_FLAGS]
 /*
  * Set up intermediate environment (new sp and gd) and call
  * relocate_code(addr_moni). Trick here is that we'll return
@@ -122,6 +124,10 @@ ENTRY(_main)
 	ldr	x9, [x18, #GD_RELOC_OFF]	/* x9 <- gd->reloc_off */
 	add	lr, lr, x9	/* new return address after relocation */
 	ldr	x0, [x18, #GD_RELOCADDR]	/* x0 <- gd->relocaddr */
+
+	tst	x1, #GD_FLG_SKIP_RELOC
+	bne	relocation_return
+
 	b	relocate_code
 
 relocation_return:
-- 
2.30.0

Re: [PATCH 2/2] arm: crt0_64: support skip u-boot relocation

[Simon Glass]

Hi Peng,

On Wed, 13 Oct 2021 at 03:18, Peng Fan (OSS) <peng.fan@oss.nxp.com> wrote:
>
> From: Peng Fan <peng.fan@nxp.com>
>
> U-Boot binary is quite large with more options enabled, it not hurt
> on real silicon with high performance. But on simulation platform,
> it is quite slow to relocate the U-Boot binary to new address,
> so let's support skipping relocation.
>
> Users could use 'gd->flags |= GD_FLG_SKIP_RELOC;' in board_early_init_f
> or other place that early than relocate_code.
>
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  arch/arm/lib/crt0_64.S | 6 ++++++
>  1 file changed, 6 insertions(+)

Reviewed-by: Simon Glass <sjg@chromium.org>

>
> diff --git a/arch/arm/lib/crt0_64.S b/arch/arm/lib/crt0_64.S
> index 680e674fa3..d57ca84ee4 100644
> --- a/arch/arm/lib/crt0_64.S
> +++ b/arch/arm/lib/crt0_64.S
> @@ -12,6 +12,7 @@
>  #include <config.h>
>  #include <asm-offsets.h>
>  #include <asm/macro.h>
> +#include <asm-generic/global_data.h>
>  #include <linux/linkage.h>
>
>  /*
> @@ -95,6 +96,7 @@ ENTRY(_main)
>         bl      board_init_f
>
>  #if !defined(CONFIG_SPL_BUILD)
> +       ldr     x1, [x18, #GD_FLAGS]
>  /*
>   * Set up intermediate environment (new sp and gd) and call
>   * relocate_code(addr_moni). Trick here is that we'll return
> @@ -122,6 +124,10 @@ ENTRY(_main)
>         ldr     x9, [x18, #GD_RELOC_OFF]        /* x9 <- gd->reloc_off */
>         add     lr, lr, x9      /* new return address after relocation */
>         ldr     x0, [x18, #GD_RELOCADDR]        /* x0 <- gd->relocaddr */
> +
> +       tst     x1, #GD_FLG_SKIP_RELOC
> +       bne     relocation_return

Could we document this feature somewhere, or add a comment here as to
why this is useful?

> +
>         b       relocate_code
>
>  relocation_return:
> --
> 2.30.0
>

Regards,
SImon

RE: [PATCH 1/2] board_f: fix use of GD_FLG_SKIP_RELOC

[Peng Fan (OSS)]

> Subject: Re: [PATCH 1/2] board_f: fix use of GD_FLG_SKIP_RELOC
> 
> On 10/13/21 11:54 AM, Peng Fan (OSS) wrote:
> > From: Peng Fan <peng.fan@nxp.com>
> >
> > When dtb is padded in the end of U-Boot binary, dtb should always be
> > relocated whether GD_FLG_SKIP_RELOC set or not, otherwise dtb maybe
> > corrupted.
> >
> > Need copy old gd contents to new_gd area, this may not needed on x86
> > or arc, but needed for ARM64, because crt0_64.S points x18 to new_gd,
> > considering gd is a small area, and common/board_f.c also use new_gd,
> > so let's always copy it.
> 
> Have a look at these patches:
> 
> https://patchwork.ozlabs.org/project/uboot/patch/20211010215209.872181
> -1-marek.vasut@gmail.com/
> https://patchwork.ozlabs.org/project/uboot/patch/20211010215209.872181
> -2-marek.vasut@gmail.com/
> https://patchwork.ozlabs.org/project/uboot/patch/20211010214410.870766
> -1-marek.vasut+renesas@gmail.com/

Oh, I should check mails before I work on this. Will look at your patches.

Thanks,
Peng.