[RFC PATCH] semihosting/arm-compat: remove heuristic softmmu SYS_HEAPINFO

[Alex Bennée]

The previous numbers were a guess at best. While we could extract the
information from a loaded ELF file via -kernel we could still get
tripped up by self decompressing or relocating code. Besides sane
library code has access to the same symbols in run time to make a
determination of the location of the heap.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Andrew <astrauss11@gmail.com>
---
 semihosting/arm-compat-semi.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c
index 1c29146dcf..041b4f6c04 100644
--- a/semihosting/arm-compat-semi.c
+++ b/semihosting/arm-compat-semi.c
@@ -1165,12 +1165,10 @@ target_ulong do_common_semihosting(CPUState *cs)
     case TARGET_SYS_HEAPINFO:
         {
             target_ulong retvals[4];
-            target_ulong limit;
             int i;
 #ifdef CONFIG_USER_ONLY
+            target_ulong limit;
             TaskState *ts = cs->opaque;
-#else
-            target_ulong rambase = common_semi_rambase(cs);
 #endif
 
             GET_ARG(0);
@@ -1201,12 +1199,15 @@ target_ulong do_common_semihosting(CPUState *cs)
             retvals[2] = ts->stack_base;
             retvals[3] = 0; /* Stack limit.  */
 #else
-            limit = current_machine->ram_size;
-            /* TODO: Make this use the limit of the loaded application.  */
-            retvals[0] = rambase + limit / 2;
-            retvals[1] = rambase + limit;
-            retvals[2] = rambase + limit; /* Stack base */
-            retvals[3] = rambase; /* Stack limit.  */
+            /*
+             * Reporting 0 indicates we couldn't calculate the real
+             * values which should force most software to fall back to
+             * using information it has.
+             */
+            retvals[0] = 0; /* Heap Base */
+            retvals[1] = 0; /* Heap Limit */
+            retvals[2] = 0; /* Stack base */
+            retvals[3] = 0; /* Stack limit.  */
 #endif
 
             for (i = 0; i < ARRAY_SIZE(retvals); i++) {
-- 
2.20.1