All of lore.kernel.org
 help / color / mirror / Atom feed
From: Janosch Frank <frankja@linux.ibm.com>
To: linux-s390@vger.kernel.org, kvm@vger.kernel.org
Subject: [kvm-unit-tests PATCH v6 03/11] s390x: Make tests bootable from disk
Date: Fri, 18 Jan 2019 11:41:56 +0000	[thread overview]
Message-ID: <20190118114204.147868-4-frankja@linux.ibm.com> (raw)

Currently tests are run with the --kernel option of Qemu, which will
load the ELF file and jump to the start address. When booting from
disk, we need to specify a start address. This is done by setting the
initial short PSW at 0x0.

.text was moved to 0x11000 because the bootloader can write from
0x10480 until 0x11000 if it has a lot to write. 0x10480 to 0x10600 was
not enough safe space.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
---
 s390x/Makefile   |  2 +-
 s390x/cstart64.S |  8 +++++++-
 s390x/flat.lds   | 13 ++++++++++++-
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/s390x/Makefile b/s390x/Makefile
index ede2961..ed6ef0b 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -50,7 +50,7 @@ FLATLIBS = $(libcflat)
 %.elf: %.o $(FLATLIBS) $(SRCDIR)/s390x/flat.lds $(cstart.o)
 	$(CC) $(CFLAGS) -c -o $(@:.elf=.aux.o) \
 		$(SRCDIR)/lib/auxinfo.c -DPROGNAME=\"$@\"
-	$(CC) $(LDFLAGS) -o $@ -T $(SRCDIR)/s390x/flat.lds -Ttext=0x10000 \
+	$(CC) $(LDFLAGS) -o $@ -T $(SRCDIR)/s390x/flat.lds \
 		$(filter %.o, $^) $(FLATLIBS) $(@:.elf=.aux.o)
 	$(RM) $(@:.elf=.aux.o)
 	@chmod a-x $@
diff --git a/s390x/cstart64.S b/s390x/cstart64.S
index dc7ddd6..385915e 100644
--- a/s390x/cstart64.S
+++ b/s390x/cstart64.S
@@ -14,7 +14,13 @@
 
 .section .init
 
-/* entry point - for KVM + TCG we directly start in 64 bit mode */
+/*
+ * Short init between 0x10000 and 0x10480 and then jump to 0x11000.
+ * 0x10480 - 0x11000 are written to by bootloader.
+ *
+ * For KVM and TCG kernel boot we are in 64 bit z/Arch mode.
+ * When booting from disk the initial short psw is in 31 bit mode.
+ */
 	.globl start
 start:
 	/* setup stack */
diff --git a/s390x/flat.lds b/s390x/flat.lds
index b6e2172..977af7c 100644
--- a/s390x/flat.lds
+++ b/s390x/flat.lds
@@ -1,10 +1,21 @@
 SECTIONS
 {
+	/*
+	 * Initial short psw for disk boot, with 31 bit addressing for
+	 * non z/Arch environment compatibility and the instruction
+	 * address 0x10000 (cstart64.S .init).
+	 */
+	.lowcore : {
+		. = 0;
+		 LONG(0x00080000)
+		 LONG(0x80010000)
+	}
+	. = 0x10000;
 	.text : {
 		*(.init)
 		. = 0x480;
 		ipl_args = .;
-		. = 0x600;
+		.  = 0x1000;
 		*(.text)
 		*(.text.*)
 	}
-- 
2.14.3

                 reply	other threads:[~2019-01-18 11:41 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190118114204.147868-4-frankja@linux.ibm.com \
    --to=frankja@linux.ibm.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.