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| author | mario.six@gdsys.cc <mario.six@gdsys.cc> | 2017-01-17 08:33:47 +0100 |
|---|---|---|
| committer | York Sun <york.sun@nxp.com> | 2017-01-31 09:35:06 -0800 |
| commit | e80311a5f09967b2c33a772c26983abfbc821140 (patch) | |
| tree | 31f9b38ead0b52626eacc8e806db76c10686f16a /arch/powerpc | |
| parent | cf4128e53caa4f7b0a6586fc3f10690d5c05db31 (diff) | |
| download | u-boot-e80311a5f09967b2c33a772c26983abfbc821140.zip u-boot-e80311a5f09967b2c33a772c26983abfbc821140.tar.gz u-boot-e80311a5f09967b2c33a772c26983abfbc821140.tar.bz2 | |
powerpc: mpc83xx: Minimize r1 modification
The r1 register is modified several times during the cache-ram setup of
the MPC83xx SoCs.
Since this SP modification confuses debuggers, we use a general purpose
register to compute the new stack pointer value, and only set the SP
once after all computations are done.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Joakim Tjernlund <Joakim.Tjernlund@infinera.com>
Reviewed-by: York Sun <york.sun@nxp.com>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/cpu/mpc83xx/start.S | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/powerpc/cpu/mpc83xx/start.S b/arch/powerpc/cpu/mpc83xx/start.S index 0001687..c366f61 100644 --- a/arch/powerpc/cpu/mpc83xx/start.S +++ b/arch/powerpc/cpu/mpc83xx/start.S @@ -258,14 +258,17 @@ in_flash: #endif /* set up the stack pointer in our newly created - * cache-ram (r1) */ - lis r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@h - ori r1, r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@l + * cache-ram; use r3 to keep the new SP for now to + * avoid overiding the SP it uselessly */ + lis r3, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@h + ori r3, r3, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@l li r0, 0 /* Make room for stack frame header and */ - stwu r0, -4(r1) /* clear final stack frame so that */ - stwu r0, -4(r1) /* stack backtraces terminate cleanly */ + stwu r0, -4(r3) /* clear final stack frame so that */ + stwu r0, -4(r3) /* stack backtraces terminate cleanly */ + /* Finally, actually set SP */ + mr r1, r3 /* let the C-code set up the rest */ /* */ |