Add support for 64bit LE ABI v1 and v2 support

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>

--

v2: With the parameters changed for go-64, kernel loading from commandline broke
v3: (client-exec) calls start-elf64 directly, fix args

6 files changed, 77 insertions, 18 deletions

diff --git a/board-qemu/slof/OF.fs b/board-qemu/slof/OF.fs
index a4f1064..061df66 100644
--- a/board-qemu/slof/OF.fs
+++ b/board-qemu/slof/OF.fs
@@ -240,14 +240,12 @@ set-default-console
 
 0 VALUE direct-ram-boot-base
 0 VALUE direct-ram-boot-size
-CREATE boot-opd 10 ALLOT
 
 : (boot-ram)
     direct-ram-boot-size 0<> IF
         ." Booting from memory..." cr
-	direct-ram-boot-base boot-opd !
-	0 boot-opd 8 + !
-	s" boot-opd to go-entry" evaluate
+	s" go-args 2@ " evaluate
+	direct-ram-boot-base 0 0
 	s" true state-valid ! " evaluate
 	s" disable-watchdog go-64" evaluate
     THEN
diff --git a/include/libelf.h b/include/libelf.h
index 495d697..ee55375 100644
--- a/include/libelf.h
+++ b/include/libelf.h
@@ -89,6 +89,7 @@ unsigned long elf_load_segments64(void *file_addr, signed long offset,
 long elf_get_base_addr(void *file_addr);
 long elf_get_base_addr32(void *file_addr);
 long elf_get_base_addr64(void *file_addr);
+uint32_t elf_get_eflags_64(void *file_addr);
 
 void elf_relocate64(void *file_addr, signed long offset);
 
diff --git a/lib/libelf/elf.c b/lib/libelf/elf.c
index 1340103..27fd51d 100644
--- a/lib/libelf/elf.c
+++ b/lib/libelf/elf.c
@@ -80,7 +80,9 @@ elf_check_file(unsigned long *file_addr)
  * @param pre_load   handler that is called before copying a segment
  * @param post_load  handler that is called after copying a segment
  * @return           1 for a 32 bit file
- *                   2 for a 64 bit file
+ *                   2 for a 64 bit BE file
+ *                   3 for a 64 bit LE ABIv1 file
+ *                   3 for a 64 bit LE ABIv2 file
  *                   anything else means an error during load
  */
 int
@@ -89,6 +91,7 @@ elf_load_file(void *file_addr, unsigned long *entry,
               void (*post_load)(void*, long))
 {
 	int type = elf_check_file(file_addr);
+	struct ehdr *ehdr = (struct ehdr *) file_addr;
 
 	switch (type) {
 	case 1:
@@ -96,9 +99,15 @@ elf_load_file(void *file_addr, unsigned long *entry,
 		break;
 	case 2:
 		*entry = elf_load_segments64(file_addr, 0, pre_load, post_load);
+		if (ehdr->ei_data != ELFDATA2MSB) {
+			uint32_t flags = elf_get_eflags_64(file_addr);
+			if ((flags & 0x3) == 2)
+				type = 4; /* LE64 ABIv2 */
+			else
+				type = 3; /* LE64 ABIv1 */
+		}
 		break;
 	}
-
 	return type;
 }
 
diff --git a/lib/libelf/elf64.c b/lib/libelf/elf64.c
index faddbfb..62ac885 100644
--- a/lib/libelf/elf64.c
+++ b/lib/libelf/elf64.c
@@ -462,3 +462,10 @@ elf_byteswap_header64(void *file_addr)
 		phdr = (struct phdr64 *)(((uint8_t *)phdr) + ehdr->e_phentsize);
 	}
 }
+
+uint32_t elf_get_eflags_64(void *file_addr)
+{
+	struct ehdr64 *ehdr = (struct ehdr64 *) file_addr;
+
+	return ehdr->e_flags;
+}
diff --git a/slof/fs/boot.fs b/slof/fs/boot.fs
index c9cc3b1..97eca1e 100644
--- a/slof/fs/boot.fs
+++ b/slof/fs/boot.fs
@@ -70,13 +70,51 @@ defer go ( -- )
    THEN
    -6d boot-exception-handler ABORT
 ;
-: go-64 ( -- )
-   state-valid @ IF
-      0 ciregs >r3 ! 0 ciregs >r4 !
-      go-args 2@ go-entry start-elf64 client-data
-      claim-list elf-release 0 to claim-list
-   THEN
-   -6d boot-exception-handler ABORT
+
+: go-64 ( args len entry r2 r12 -- )
+    0 ciregs >r3 ! 0 ciregs >r4 !
+    start-elf64 client-data
+    claim-list elf-release 0 to claim-list
+;
+
+: go-64-be ( -- )
+    state-valid @ IF
+	go-args 2@
+	go-entry @
+	go-entry 8 + @
+	0 go-64
+    THEN
+    -6d boot-exception-handler ABORT
+;
+
+\ FIXME : how to do this correctly, currently this hangs.
+: set-le ( -- )
+    ." Changing endianness "
+    msr@ 1 or msr!
+    ."  done "
+    msr@ . cr
+;
+
+: go-64-lev1
+    state-valid @ IF
+	go-args 2@
+	go-entry @ xbflip
+	go-entry 8 + @ xbflip
+	0
+	\ set-le
+	go-64
+    THEN
+    -6d boot-exception-handler ABORT
+;
+
+: go-64-lev2
+    state-valid @ IF
+	go-args 2@
+	go-entry 0 go-entry
+	\ set-le
+	go-64
+    THEN
+    -6d boot-exception-handler ABORT
 ;
 
 : load-elf-init ( arg len file-addr -- success )
@@ -91,7 +129,9 @@ defer go ( -- )
    ( arg len true claim-list entry elftype )
    CASE
       1  OF ['] go-32 ENDOF           ( arg len true claim-list entry go )
-      2  OF ['] go-64 ENDOF           ( arg len true claim-list entry go )
+      2  OF ['] go-64-be   ENDOF           ( arg len true claim-list entry go )
+      3  OF ['] go-64-lev1 ENDOF           ( arg len true claim-list entry go )
+      4  OF ['] go-64-lev2 ENDOF           ( arg len true claim-list entry go )
       dup OF ['] no-go to go
          2drop 3drop false EXIT   ENDOF                   ( false )
    ENDCASE
diff --git a/slof/fs/loaders.fs b/slof/fs/loaders.fs
index 97545b7..3603dd4 100644
--- a/slof/fs/loaders.fs
+++ b/slof/fs/loaders.fs
@@ -19,9 +19,11 @@ CREATE load-list 2 cells allot load-list 2 cells erase
    msr@ 7fffffffffffffff and 2000 or ciregs >srr1 ! call-client
 ;
 
-: start-elf64 ( arg len entry -- )
-   msr@ 2000 or ciregs >srr1 !
-   dup 8 + @ ciregs >r2 ! @ call-client \ entry point is pointer to .opd
+: start-elf64 ( arg len entry r2 r12 -- )
+    msr@ 2000 or ciregs >srr1 !
+    ciregs >r12 !
+    ciregs >r2  !
+    call-client \ entry point is pointer to .opd
 ;
 
 : set-bootpath
@@ -47,7 +49,9 @@ CREATE load-list 2 cells allot load-list 2 cells erase
    s" snk" romfs-lookup 0<> IF
       \ Load SNK client 15 MiB after Paflof... FIXME: Hard-coded offset is ugly!
       paflof-start f00000 +
-      elf-load-file-to-addr drop start-elf64 client-data
+      elf-load-file-to-addr drop \ FIXME - check this for LE, currently its BE only
+      dup @ swap 8 + @ 0         \ populate entry r2 r12
+      start-elf64 client-data
    ELSE
       2drop false
    THEN