diff mbox series

[3/3] sparc32: advertise relocatable kernel with HdrS 0x0300

Message ID 20260814105723.3454511-4-linmag7@gmail.com
State New
Headers show
Series sparc32: allow a kernel loaded away from the start of RAM | expand

Commit Message

Magnus Lindholm Aug. 14, 2026, 10:52 a.m. UTC 
HdrS version 0x0300 tells the boot loader that the kernel supports being
located somewhere other than physical 0x4000, which is where SILO places
the image on the traditional path. Anything older is copied back down
there, and refused outright when it no longer fits.

sparc32 could not make that claim before, because setup_arch() took
phys_base from the lowest memory bank rather than from what PAGE_OFFSET
maps to. It can now, so say so.

Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
---
 arch/sparc/kernel/head_32.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Sam Ravnborg Aug. 14, 2026, 8:48 p.m. UTC | #1 
Hi Magnus.

On Fri, Aug 14, 2026 at 12:52:34PM +0200, Magnus Lindholm wrote:
> HdrS version 0x0300 tells the boot loader that the kernel supports being
> located somewhere other than physical 0x4000, which is where SILO places
> the image on the traditional path. Anything older is copied back down
> there, and refused outright when it no longer fits.
OK, if I knew this it was paged out a long time ago.

> 
> sparc32 could not make that claim before, because setup_arch() took
> phys_base from the lowest memory bank rather than from what PAGE_OFFSET
> maps to. It can now, so say so.
> 
> Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
diff mbox series

Patch

diff --git a/arch/sparc/kernel/head_32.S b/arch/sparc/kernel/head_32.S
index 8c320fa25a67..11a1746829a4 100644
--- a/arch/sparc/kernel/head_32.S
+++ b/arch/sparc/kernel/head_32.S
@@ -69,7 +69,7 @@  sun4e_notsup:
  */
 	.ascii	"HdrS"
 	.word	LINUX_VERSION_CODE
-	.half	0x0203		/* HdrS version */
+	.half	0x0300		/* HdrS version */
 root_flags:
 	.half	1
 root_dev: