From: Alan Cox <alan@linux.intel.com>
Date: Sat, 24 Jan 2015 21:22:19 +0000 (+0000)
Subject: exec: introduce MAPBASE as distinguished from PROGBASE
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=a7ccb63c1e17cb218428469449429ad1065666a4;p=FUZIX.git

exec: introduce MAPBASE as distinguished from PROGBASE

PROGBASE is where the code starts
MAPBASE is where the memory mapping begins

This is needed for systems with a low mapped common
---

diff --git a/Kernel/include/kernel.h b/Kernel/include/kernel.h
index 86c3b5f0..054cf7e3 100644
--- a/Kernel/include/kernel.h
+++ b/Kernel/include/kernel.h
@@ -39,6 +39,10 @@ From UZI by Doug Braun and UZI280 by Stefan Nitschke.
 #define PTABSIZE 15      /* Process table size. */
 #endif
 
+#ifndef MAPBASE		/* Usually the start of program and map match */
+#define MAPBASE PROGBASE
+#endif
+
 #define MAXTICKS     10   /* Max ticks before switching out (time slice)
                             default process time slice */
 // #define MAXBACK      3   /* Process time slice for tasks not connected
diff --git a/Kernel/syscall_exec.c b/Kernel/syscall_exec.c
index 79683866..3b325725 100644
--- a/Kernel/syscall_exec.c
+++ b/Kernel/syscall_exec.c
@@ -158,7 +158,7 @@ int16_t _execve(void)
 		goto nogood3;	/* SN */
 
 	/* This must be the last test as it makes changes if it works */
-	if (pagemap_realloc(top - PROGBASE))
+	if (pagemap_realloc(top - MAPBASE))
 		goto nogood3;
 
 	/* From this point on we are commmited to the exec() completing */