[U-Boot] [PATCH v3 3/3] README: update ARM register usage

Jeroen Hofstee
2013-09-21T12:04:42Z

Besides the change of this patchset it also updates the
README to reflect that GOT-generated relocations are no
longer supported on ARM.

cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
README | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/README b/README
index ccd47fa..ec3e60b 100644
--- a/README
+++ b/README
@@ -5588,15 +5588,17 @@ On ARM, the following registers are used:

R0: function argument word/integer result
R1-R3: function argument word
- R9: GOT pointer
- R10: stack limit (used only if stack checking if enabled)
+ R9: platform specific
+ R10: stack limit (used only if stack checking is enabled)
R11: argument (frame) pointer
R12: temporary workspace
R13: stack pointer
R14: link register
R15: program counter

- ==> U-Boot will use R8 to hold a pointer to the global data
+ ==> U-Boot will use R9 to hold a pointer to the global data
+
+ Note: on ARM, only R_ARM_RELATIVE relocations are supported.

On Nios II, the ABI is documented here:
http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
--
1.8.1.2