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| author | Robin Getz <robin.getz@analog.com> | 2009-08-17 15:23:02 +0000 |
|---|---|---|
| committer | Mike Frysinger <vapier@gentoo.org> | 2009-09-02 05:14:02 -0400 |
| commit | c4db335c2e0805e1ce4c33d278b77492c0812353 (patch) | |
| tree | f34ad8f1791e0a76255706929cf7b7bb534c2513 /doc | |
| parent | 574b70df03fba0ea635e2fe71fbd7b97d19b706a (diff) | |
| download | blackbird-obmc-uboot-c4db335c2e0805e1ce4c33d278b77492c0812353.tar.gz blackbird-obmc-uboot-c4db335c2e0805e1ce4c33d278b77492c0812353.zip | |
Blackfin: change global data register from P5 to P3
Since the Blackfin ABI favors higher scratch registers by default, use the
last scratch register (P3) for global data rather than the first (P5).
This allows the compiler's register allocator to use higher number scratch
P registers, which in turn better matches the Blackfin instruction set,
which reduces the size of U-Boot by more than 1024 bytes...
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.standalone | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/doc/README.standalone b/doc/README.standalone index 81b949a0aa..885c92fb3a 100644 --- a/doc/README.standalone +++ b/doc/README.standalone @@ -21,7 +21,7 @@ Design Notes on Exporting U-Boot Functions to Standalone Applications: 2. The pointer to the jump table is passed to the application in a machine-dependent way. PowerPC, ARM, MIPS and Blackfin architectures use a dedicated register to hold the pointer to the 'global_data' - structure: r2 on PowerPC, r8 on ARM, k0 on MIPS, and P5 on Blackfin. + structure: r2 on PowerPC, r8 on ARM, k0 on MIPS, and P3 on Blackfin. The x86 architecture does not use such a register; instead, the pointer to the 'global_data' structure is passed as 'argv[-1]' pointer. |
