[PATCH v5 3/5] semihosting/arm-compat-semi: don't use SET_ARG to report SYS_HEAPINFO

[Alex Bennée]

As per the spec:

  the PARAMETER REGISTER contains the address of a pointer to a
  four-field data block.

So we need to follow arg0 and place the results of SYS_HEAPINFO there.

Fixes: 3c37cfe0b1 ("semihosting: Change internal common-semi interfaces to use 
CPUState *")
Bug: https://bugs.launchpad.net/bugs/1915925
Cc: Bug 1915925 <1915925@bugs.launchpad.net>
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

---
v3
  - just revert the old behaviour
---
 semihosting/arm-compat-semi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c
index 0f0e129a7c..fe079ca93a 100644
--- a/semihosting/arm-compat-semi.c
+++ b/semihosting/arm-compat-semi.c
@@ -1214,7 +1214,11 @@ target_ulong do_common_semihosting(CPUState *cs)
             for (i = 0; i < ARRAY_SIZE(retvals); i++) {
                 bool fail;
 
-                fail = SET_ARG(i, retvals[i]);
+                if (is_64bit_semihosting(env)) {
+                    fail = put_user_u64(retvals[i], arg0 + i * 8);
+                } else {
+                    fail = put_user_u32(retvals[i], arg0 + i * 4);
+                }
 
                 if (fail) {
                     /* Couldn't write back to argument block */
-- 
2.20.1