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authorLihua Zhao <lihua.zhao@windriver.com>2019-11-15 00:21:17 -0800
committerTom Rini <trini@konsulko.com>2019-12-03 08:43:23 -0500
commit1e26f648885719cb6a105ae3562e8d840e75a6b8 (patch)
treeda6eb468bce859e1fe827858172f134f5089005b /doc
parent9a94a8994aa9f3722a832cd5c84af24c5eaab5e8 (diff)
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>
Diffstat (limited to 'doc')
-rw-r--r--doc/README.vxworks13
1 files changed, 13 insertions, 0 deletions
diff --git a/doc/README.vxworks b/doc/README.vxworks
index 3e08711207..12a0d744d8 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 @@ From VxWorks 7, VxWorks starts adopting device tree as its hardware description
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 @@ For ARM, the calling convention is shown below:
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: