summaryrefslogtreecommitdiff
path: root/README
diff options
context:
space:
mode:
authorJeroen Hofstee <jeroen@myspectrum.nl>2013-09-21 14:04:42 +0200
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2013-09-23 18:00:36 +0200
commit12eba1b49380988fd87cc0b3af44014cca8b71c4 (patch)
tree430dd60722cb8f14b1b4fb95196a167f6bb570db /README
parentfe1378a961e508b31b1f29a2bb08ba1dac063155 (diff)
README: update ARM register usage
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>
Diffstat (limited to 'README')
-rw-r--r--README8
1 files changed, 5 insertions, 3 deletions
diff --git a/README b/README
index f27e578e720..2fcad7ff856 100644
--- a/README
+++ b/README
@@ -5587,15 +5587,17 @@ 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