diff options
| author | Heinrich Schuchardt <xypron.glpk@gmx.de> | 2020-10-15 07:40:57 +0200 |
|---|---|---|
| committer | Heinrich Schuchardt <xypron.glpk@gmx.de> | 2020-12-15 09:31:26 +0100 |
| commit | b2107a4b77458424d60dda05e778319eadcde0ed (patch) | |
| tree | 6347be31ebbe1fc6dfc07eed61ac097f85081d01 /doc | |
| parent | c2067021556a623a56b931cf3975f0fe1e195cb7 (diff) | |
doc: global data pointer on x86, x86_64
On x86 the global data pointer is stored in register fs.
On x86_64 no register is used for the global data pointer.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/develop/global_data.rst | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/doc/develop/global_data.rst b/doc/develop/global_data.rst index 9e7c8a24da..230ebcd860 100644 --- a/doc/develop/global_data.rst +++ b/doc/develop/global_data.rst @@ -33,8 +33,10 @@ On most architectures the global data pointer is stored in a register. +------------+----------+ | SuperH | r13 | +------------+----------+ +| x86 32bit | fs | ++------------+----------+ -The sandbox, x86, and Xtensa are notable exceptions. +The sandbox, x86_64, and Xtensa are notable exceptions. Clang for ARM does not support assigning a global register. When using Clang gd is defined as an inline function using assembly code. This adds a few bytes |