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authorThomas Chou <thomas@wytron.com.tw>2010-08-16 10:49:44 +0800
committerScott McNutt <smcnutt@psyent.com>2010-08-19 22:15:49 -0400
commit7a6a7d10e6b96ab4a5c0d8852802ec52be2b582e (patch)
treef8aad9ce824371f69022db5aedacd0f11477345d /arch/nios2
parent62a05573822fc253a1ad5037482511347d6abaa5 (diff)
downloadu-boot-linaro-stable-7a6a7d10e6b96ab4a5c0d8852802ec52be2b582e.tar.gz
nios2: fix out of reach case for do_reset
There is a limitation (or bug?) of nios2 toolchain. The nios2 gcc didn't generate correct code when the reset vector is passed as a constant. It just generated a direct "call", which was wrong when the reset vector was not located in the same 256MB span as u-boot. The "Nios II Processor Reference Handbook" said, "call can transfer execution anywhere within the 256 MByte range determined by PC31..28. The Nios II GNU linker does not automatically handle cases in which the address is out of this range." So we have to use registered "callr" instruction to do the job. Signed-off-by: Thomas Chou <thomas@wytron.com.tw> Signed-off-by: Scott McNutt <smcnutt@psyent.com>
Diffstat (limited to 'arch/nios2')
-rw-r--r--arch/nios2/cpu/cpu.c11
-rw-r--r--arch/nios2/include/asm/system.h5
2 files changed, 10 insertions, 6 deletions
diff --git a/arch/nios2/cpu/cpu.c b/arch/nios2/cpu/cpu.c
index 6379534a0..d9c654477 100644
--- a/arch/nios2/cpu/cpu.c
+++ b/arch/nios2/cpu/cpu.c
@@ -40,11 +40,10 @@ int checkcpu (void)
return (0);
}
-
-int do_reset (void)
+int do_reset(void)
{
- void (*rst)(void) = (void(*)(void))CONFIG_SYS_RESET_ADDR;
- disable_interrupts ();
- rst();
- return(0);
+ disable_interrupts();
+ /* indirect call to go beyond 256MB limitation of toolchain */
+ nios2_callr(CONFIG_SYS_RESET_ADDR);
+ return 0;
}
diff --git a/arch/nios2/include/asm/system.h b/arch/nios2/include/asm/system.h
index bb03ca531..086d92bb0 100644
--- a/arch/nios2/include/asm/system.h
+++ b/arch/nios2/include/asm/system.h
@@ -56,4 +56,9 @@
((flags & NIOS2_STATUS_PIE_MSK) == 0x0); \
})
+/* indirect call to go beyond 256MB limitation of toolchain */
+#define nios2_callr(addr) __asm__ __volatile__ ( \
+ "callr %0" \
+ : : "r" (addr))
+
#endif /* __ASM_NIOS2_SYSTEM_H */