summaryrefslogtreecommitdiff
path: root/examples
diff options
context:
space:
mode:
authorLukas Auer <lukas.auer@aisec.fraunhofer.de>2019-01-04 01:37:32 +0100
committerAndes <uboot@andestech.com>2019-01-15 09:36:31 +0800
commitcbb860f2c89c05c4c1d571f61bb76650db489d7d (patch)
tree419f667093fc4c6e353fc4ce06e27a69693dd6fb /examples
parent3c37278ff18577b711b14a1c2fcec37daa959f0a (diff)
riscv: replace use of callee-saved register in standalone
Register x19 (s3) is a callee-saved register. It must not be used to load and jump to exported functions without saving it beforehand. Replace it with t0, a temporary and caller-saved register. Change the code comment to reflect this and fix it to correctly list gp as the register with the pointer to global data. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
Diffstat (limited to 'examples')
-rw-r--r--examples/standalone/stubs.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/examples/standalone/stubs.c b/examples/standalone/stubs.c
index fadde669fa..f37d209da6 100644
--- a/examples/standalone/stubs.c
+++ b/examples/standalone/stubs.c
@@ -174,16 +174,16 @@ gd_t *global_data;
: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "$r16");
#elif defined(CONFIG_RISCV)
/*
- * t7 holds the pointer to the global_data. gp is call clobbered.
+ * gp holds the pointer to the global_data. t0 is call clobbered.
*/
#define EXPORT_FUNC(f, a, x, ...) \
asm volatile ( \
" .globl " #x "\n" \
#x ":\n" \
-" lw x19, %0(gp)\n" \
-" lw x19, %1(x19)\n" \
-" jr x19\n" \
- : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "x19");
+" lw t0, %0(gp)\n" \
+" lw t0, %1(t0)\n" \
+" jr t0\n" \
+ : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t0");
#elif defined(CONFIG_ARC)
/*
* r25 holds the pointer to the global_data. r10 is call clobbered.