[PATCH] Minor - eliminate the SET_GLOBAL macro.

[Kevin O'Connor]

Remove the SET_GLOBAL macro - it is no longer used and since it was
only available in "32bit flat" mode it does not have much use.

Signed-off-by: Kevin O'Connor 
---
 README        | 21 ++++++++++-----------
 src/biosvar.h |  4 ----
 2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/README b/README
index 6844e52..1e61e2f 100644
--- a/README
+++ b/README
@@ -104,23 +104,22 @@ mode instead of a segment/offset pair.

Most BIOS variables are stored in global variables, the "BDA", or
 "EBDA" memory areas.  Because this is common, three sets of helper
-macros (GET/SET_GLOBAL, GET/SET_BDA, and GET/SET_EBDA) are available
-to simplify these accesses.  Also, an area in the 0xc0000-0xf0000
-memory range is made available for internal BIOS run-time variables
-that are marked with the VARLOW attribute.  These variables can then
-be accessed with the GET/SET_LOW macros.
+macros (GET_GLOBAL, GET/SET_BDA, and GET/SET_EBDA) are available to
+simplify these accesses.  Also, an area in the 0xc0000-0xf0000 memory
+range is made available for internal BIOS run-time variables that are
+marked with the VARLOW attribute.  These variables can then be
+accessed with the GET/SET_LOW macros.

Global variables defined in the C code can be read in 16bit mode if
 the variable declaration is marked with VAR16, VARFSEG, or VAR16FIXED.
 The GET_GLOBAL macro will then allow read access to the variable.
 Global variables are stored in the 0xf000 segment.  Because the
 f-segment is marked read-only during run-time, the 16bit code is not
-permitted to change the value of 16bit variables (use of the
-SET_GLOBAL macro from 16bit mode will cause a link error).  Code
-running in 32bit mode can not access variables with VAR16, but can
-access variables marked with VARFSEG, VARLOW, VAR16FIXED, or with no
-marking at all.  The 32bit code can use the GET/SET_GLOBAL macros, but
-they are not required.
+permitted to change the value of 16bit variables.  Code running in
+32bit mode can not access variables with VAR16, but can access
+variables marked with VARFSEG, VARLOW, VAR16FIXED, or with no marking
+at all.  The 32bit code can use the GET_GLOBAL macros, but they are
+not required.

GCC 16 bit stack limitations:
diff --git a/src/biosvar.h b/src/biosvar.h
index 051cd1e..58bcbce 100644
--- a/src/biosvar.h
+++ b/src/biosvar.h
@@ -99,10 +99,6 @@ static inline u16 get_global_seg(void) {
 #define GET_GLOBAL(var)                                                 \
     GET_VAR(GLOBAL_SEGREG, *(typeof(&(var)))((void*)&(var)              \
                                              + get_global_offset()))
-#define SET_GLOBAL(var, val) do {               \
-        ASSERT32FLAT();                         \
-        (var) = (val);                          \
-    } while (0)
 #if MODESEGMENT
 #define GLOBALFLAT2GLOBAL(var) ((typeof(var))((void*)(var) - BUILD_BIOS_ADDR))
 #else