From 771d631f798c2d029335d5b19ec3e3bc960d1f1f Mon Sep 17 00:00:00 2001
From: NicJA <NicJA@fb15a70f-31f2-0310-bbcc-cdcc74a49acc>
Date: Sun, 8 Jan 2017 20:31:04 +0000
Subject: [PATCH] update comment about first memmap. make sure the stack isn't
 within our regions before registering it as a rom block. Allow sysbase in
 either of the fastmem blocks after a reset.

git-svn-id: https://svn.aros.org/svn/aros/trunk/AROS@53186 fb15a70f-31f2-0310-bbcc-cdcc74a49acc
---
 arch/all-unix/kernel/kernel_startup.c | 52 +++++++++++++++++++++++++----------
 1 file changed, 38 insertions(+), 14 deletions(-)

diff --git a/arch/all-unix/kernel/kernel_startup.c b/arch/all-unix/kernel/kernel_startup.c
index d2973f0464..fe0a46ccef 100644
--- a/arch/all-unix/kernel/kernel_startup.c
+++ b/arch/all-unix/kernel/kernel_startup.c
@@ -50,7 +50,8 @@ struct HostInterface *HostIFace;
 THIS_PROGRAM_HANDLES_SYMBOLSET(STARTUP)
 DEFINESET(STARTUP);
 
-#define CHIPMEMSIZE    (16 * 1024 * 1024)
+#define CHIPMEMSIZE                     (16 * 1024 * 1024)
+#define STACKINRANGE(ptr, start, length)     (((IPTR)ptr > start) && ((IPTR)ptr <= (start + length)))
 
 /*
  * Kickstart entry point. Note that our code area is already made read-only by the bootstrap.
@@ -70,7 +71,7 @@ int __startup startup(struct TagItem *msg, ULONG magic)
     struct HostInterface *hif = NULL;
     struct mb_mmap *mmap = NULL;
     unsigned long mmap_len = 0;
-    BOOL mem_tlsf = FALSE;
+    BOOL mem_tlsf = FALSE, host_stack = TRUE, sysb_safe = FALSE;
 
     UWORD *ranges[] = {NULL, NULL, (UWORD *)-1};
 
@@ -176,24 +177,36 @@ int __startup startup(struct TagItem *msg, ULONG magic)
     	return -1;
     }
 
-    /* We know that memory map has only one memory range */
+    /*
+     * The first memory map entry represents low 
+     * (32bit) memory, so we allocate the "chip"
+     * memory from it.
+    */
     chipmh = (struct MemHeader *)(IPTR)mmap->addr;
     memsize = mmap->len > CHIPMEMSIZE ? CHIPMEMSIZE : mmap->len;
 
-    /* Prepare the simulated mem headers */
-    /* NOTE: two mem headers are created to cover more cases of memory system */
+    if (STACKINRANGE(_stack, mmap->addr, mmap->len))
+        host_stack = FALSE;
+    if (((IPTR)SysBase > mmap->addr) && ((IPTR)SysBase + sizeof(struct ExecBase) < mmap->addr + mmap->len))
+        sysb_safe = TRUE;
+
+    /* Prepare the chip memory's header... */
     krnCreateMemHeader("CHIP RAM", -5, chipmh, memsize, MEMF_CHIP|MEMF_PUBLIC|MEMF_LOCAL|MEMF_KICK|ARCH_31BIT);
     if (mem_tlsf)
         chipmh = krnConvertMemHeaderToTLSF(chipmh);
     bootmh = chipmh;
 
-    if (mmap->len > memsize)
+    /* If there is sufficient space left after the chip mem block, register it as fast ram... */
+    if (mmap->len > (memsize + sizeof(struct MemHeader)))
     {
         fastmh = (struct MemHeader *)(mmap->addr + memsize);
         memsize = mmap->len - memsize;
+
         krnCreateMemHeader("Fast RAM", 0, fastmh , memsize, MEMF_FAST|MEMF_PUBLIC|MEMF_LOCAL|MEMF_KICK|ARCH_31BIT);
         if (mem_tlsf)
             fastmh = krnConvertMemHeaderToTLSF(fastmh);
+
+        /* if its larger than 1MB, use it for the boot mem */
         if (memsize > (1024 * 1024))
             bootmh = fastmh;
     }
@@ -203,12 +216,19 @@ int __startup startup(struct TagItem *msg, ULONG magic)
     if (mmap_len > sizeof(struct mb_mmap))
     {
         struct mb_mmap *mmapnxt = &mmap[1];
-
         highmh = (void *)mmapnxt->addr;
 
+        if (STACKINRANGE(_stack, mmapnxt->addr, mmapnxt->len))
+            host_stack = FALSE;
+        if (((IPTR)SysBase > mmapnxt->addr) && ((IPTR)SysBase + sizeof(struct ExecBase) < mmapnxt->addr + mmapnxt->len))
+            sysb_safe = TRUE;
+
         krnCreateMemHeader("Fast RAM", 0, highmh, mmapnxt->len, MEMF_FAST|MEMF_PUBLIC|MEMF_LOCAL|MEMF_KICK);
         if (mem_tlsf)
             highmh = krnConvertMemHeaderToTLSF(highmh);
+
+        if ((bootmh == chipmh) && (mmapnxt->len > (1024 * 1024)))
+            bootmh = highmh;
     }
 #endif
 
@@ -216,7 +236,7 @@ int __startup startup(struct TagItem *msg, ULONG magic)
      * SysBase pre-validation after a warm restart.
      * This makes sure that it points to a valid accessible memory region.
      */
-    if (((IPTR)SysBase < mmap->addr) || ((IPTR)SysBase + sizeof(struct ExecBase) > mmap->addr + mmap->len))
+    if (!sysb_safe)
     	SysBase = NULL;
 
     /* Create SysBase. After this we can use basic exec services, like memory allocation, lists, etc */
@@ -248,12 +268,16 @@ int __startup startup(struct TagItem *msg, ULONG magic)
      */
     krnCreateROMHeader("Kickstart ROM", ranges[0], ranges[1]);
 
-    /*
-     * Stack memory header. This special memory header covers a little part of the programs
-     * stack so that TypeOfMem() will not return 0 for addresses pointing into the stack
-     * during initialization.
-     */
-    krnCreateROMHeader("Boot stack", _stack - AROS_STACKSIZE, _stack);
+    if (host_stack)
+    {
+        nbug("[KRN] Protecting host process stack (0x%p - 0x%p)\n", _stack - AROS_STACKSIZE, _stack);
+        /*
+         * Stack memory header. This special memory header covers a little part of the programs
+         * stack so that TypeOfMem() will not return 0 for addresses pointing into the stack
+         * during initialization.
+         */
+        krnCreateROMHeader("Boot stack", _stack - AROS_STACKSIZE, _stack);
+    }
 
     /* The following is a typical AROS bootup sequence */
     InitCode(RTF_SINGLETASK, 0);	/* Initialize early modules. This includes hostlib.resource. */
-- 
2.11.4.GIT