bootm: vxworks: Support Linux compatible standard DTB for ARM and PPC
Enhance do_bootm_vxworks() to support Linux compatible standard DTB
for ARM and PPC, when the least significant bit of flags in VxWorks
bootargs is set. Otherwise it falls back to the existing bootm flow
which is now legacy.
Signed-off-by: Lihua Zhao <lihua.zhao@windriver.com>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/doc/README.vxworks b/doc/README.vxworks
index 3e08711..12a0d74 100644
--- a/doc/README.vxworks
+++ b/doc/README.vxworks
@@ -2,6 +2,7 @@
#
# Copyright (C) 2013, Miao Yan <miao.yan@windriver.com>
# Copyright (C) 2015-2018, Bin Meng <bmeng.cn@gmail.com>
+# Copyright (C) 2019, Lihua Zhao <lihua.zhao@windriver.com>
VxWorks Support
===============
@@ -24,6 +25,15 @@
mechanism (for PowerPC and ARM), thus requiring boot interface changes.
This section will describe the new interface.
+Since VxWorks 7 SR0640 release, VxWorks starts using Linux compatible standard
+DTB for some boards. With that, the exact same bootm flow as used by Linux is
+used, which includes board-specific DTB fix up. To keep backward compatibility,
+only when the least significant bit of flags in bootargs is set, the standard
+DTB will be used. Otherwise it falls back to the legacy bootm flow.
+
+For legacy bootm flow, make sure the least significant bit of flags in bootargs
+is cleared. The calling convention is described below:
+
For PowerPC, the calling convention of the new VxWorks entry point conforms to
the ePAPR standard, which is shown below (see ePAPR for more details):
@@ -33,6 +43,9 @@
void (*kernel_entry)(void *fdt_addr)
+When using the Linux compatible standard DTB, the calling convention of VxWorks
+entry point is exactly the same as the Linux kernel.
+
When booting a VxWorks 7 kernel (uImage format), the parameters passed to bootm
is like below: