seabios: make mttr UC area setup dynamic

Set up the UC area of mtrr dynamically based on mtrr_base. This allows
the bios to work for other chipsets that might want to set the mtrr.
Since BUILD_MAX_HIGHMEM is no longer used we can remove the config parameter.

This change reverses the order of pci_setup() and smm_init() with
mtrr_setup().

Signed-off-by: Jason Baron <jbaron@redhat.com>
diff --git a/src/config.h b/src/config.h
index 0d4066d..71c0b7e 100644
--- a/src/config.h
+++ b/src/config.h
@@ -44,7 +44,6 @@
 #define BUILD_SMM_INIT_ADDR       0x38000
 #define BUILD_SMM_ADDR            0xa8000
 #define BUILD_SMM_SIZE            0x8000
-#define BUILD_MAX_HIGHMEM         0xe0000000
 
 #define BUILD_PCIMEM_START        0xe0000000
 #define BUILD_PCIMEM_END          0xfec00000    /* IOAPIC is mapped at */
diff --git a/src/mtrr.c b/src/mtrr.c
index 0957834..2cbf234 100644
--- a/src/mtrr.c
+++ b/src/mtrr.c
@@ -7,6 +7,7 @@
 #include "util.h" // dprintf
 #include "config.h" // CONFIG_*
 #include "xen.h" // usingXen
+#include "pci.h" // pcimem_start
 
 #define MSR_MTRRcap                    0x000000fe
 #define MSR_MTRRfix64K_00000           0x00000250
@@ -94,9 +95,9 @@
         wrmsr_smp(MTRRphysMask_MSR(i), 0);
     }
     /* Mark 3.5-4GB as UC, anything not specified defaults to WB */
-    wrmsr_smp(MTRRphysBase_MSR(0), BUILD_MAX_HIGHMEM | MTRR_MEMTYPE_UC);
+    wrmsr_smp(MTRRphysBase_MSR(0), pcimem_start | MTRR_MEMTYPE_UC);
     wrmsr_smp(MTRRphysMask_MSR(0)
-              , (-((1ull<<32)-BUILD_MAX_HIGHMEM) & phys_mask) | 0x800);
+              , (-((1ull<<32)-pcimem_start) & phys_mask) | 0x800);
 
     // Enable fixed and variable MTRRs; set default type.
     wrmsr_smp(MSR_MTRRdefType, 0xc00 | MTRR_MEMTYPE_WB);
diff --git a/src/post.c b/src/post.c
index 9a6dd3f..3705c3b 100644
--- a/src/post.c
+++ b/src/post.c
@@ -230,13 +230,13 @@
     timer_setup();
     mathcp_setup();
 
-    // Initialize mtrr
-    mtrr_setup();
-
     // Initialize pci
     pci_setup();
     smm_init();
 
+    // Initialize mtrr
+    mtrr_setup();
+
     // Setup Xen hypercalls
     xen_init_hypercalls();