| Message ID | 20181230182746.23448-5-lukas.auer@aisec.fraunhofer.de |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Small fixes for RISC-V | expand |
On Mon, Dec 31, 2018 at 2:30 AM Lukas Auer <lukas.auer@aisec.fraunhofer.de> wrote: > > 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> > --- > > examples/standalone/stubs.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
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.
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> --- examples/standalone/stubs.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)