svn commit: r368041 - in head: stand/efi/loader sys/amd64/amd64 sys/amd64/include sys/conf

[Maxim Sobolev]

Author: sobomax
Date: Wed Nov 25 23:19:01 2020
New Revision: 368041
URL: https://svnweb.freebsd.org/changeset/base/368041

Log:
  Unobfuscate "KERNLOAD" parameter on amd64. This change lines-up amd64 with the
  i386 and the rest of supported architectures by defining KERNLOAD in the
  vmparam.h and getting rid of magic constant in the linker script, which albeit
  documented via comment but isn't programmatically accessible at a compile time.
  
  Use KERNLOAD to eliminate another (matching) magic constant 100 lines down
  inside unremarkable TU "copy.c" 3 levels deep in the EFI loader tree.
  
  Reviewed by:	markj
  Approved by:	markj
  MFC after:	1 month
  Differential Revision:	https://reviews.freebsd.org/D27355

Modified:
  head/stand/efi/loader/copy.c
  head/sys/amd64/amd64/genassym.c
  head/sys/amd64/amd64/locore.S
  head/sys/amd64/include/vmparam.h
  head/sys/conf/ldscript.amd64

Modified: head/stand/efi/loader/copy.c
==============================================================================
--- head/stand/efi/loader/copy.c	Wed Nov 25 23:17:23 2020	(r368040)
+++ head/stand/efi/loader/copy.c	Wed Nov 25 23:19:01 2020	(r368041)
@@ -42,6 +42,7 @@ __FBSDID("$FreeBSD$");
 #if defined(__i386__) || defined(__amd64__)
 #include <machine/cpufunc.h>
 #include <machine/specialreg.h>
+#include <machine/vmparam.h>
 
 /*
  * The code is excerpted from sys/x86/x86/identcpu.c: identify_cpu(),
@@ -89,8 +90,6 @@ running_on_hyperv(void)
 	return (1);
 }
 
-#define KERNEL_PHYSICAL_BASE (2*1024*1024)
-
 static void
 efi_verify_staging_size(unsigned long *nr_pages)
 {
@@ -134,12 +133,11 @@ efi_verify_staging_size(unsigned long *nr_pages)
 		start = p->PhysicalStart;
 		end = start + p->NumberOfPages * EFI_PAGE_SIZE;
 
-		if (KERNEL_PHYSICAL_BASE < start ||
-		    KERNEL_PHYSICAL_BASE >= end)
+		if (KERNLOAD < start || KERNLOAD >= end)
 			continue;
 
 		available_pages = p->NumberOfPages -
-			((KERNEL_PHYSICAL_BASE - start) >> EFI_PAGE_SHIFT);
+			((KERNLOAD - start) >> EFI_PAGE_SHIFT);
 		break;
 	}
 

Modified: head/sys/amd64/amd64/genassym.c
==============================================================================
--- head/sys/amd64/amd64/genassym.c	Wed Nov 25 23:17:23 2020	(r368040)
+++ head/sys/amd64/amd64/genassym.c	Wed Nov 25 23:19:01 2020	(r368041)
@@ -115,6 +115,7 @@ ASSYM(val_KPML4I, KPML4I);
 ASSYM(val_PML4PML4I, PML4PML4I);
 ASSYM(VM_MAXUSER_ADDRESS, VM_MAXUSER_ADDRESS);
 ASSYM(KERNBASE, KERNBASE);
+ASSYM(KERNLOAD, KERNLOAD);
 ASSYM(DMAP_MIN_ADDRESS, DMAP_MIN_ADDRESS);
 ASSYM(DMAP_MAX_ADDRESS, DMAP_MAX_ADDRESS);
 

Modified: head/sys/amd64/amd64/locore.S
==============================================================================
--- head/sys/amd64/amd64/locore.S	Wed Nov 25 23:17:23 2020	(r368040)
+++ head/sys/amd64/amd64/locore.S	Wed Nov 25 23:19:01 2020	(r368041)
@@ -36,8 +36,9 @@
 /*
  * Compiled KERNBASE location
  */
-	.globl	kernbase, loc_PTmap, loc_PDmap, loc_PDPmap, dmapbase, dmapend
+	.globl	kernbase, kernload, loc_PTmap, loc_PDmap, loc_PDPmap, dmapbase, dmapend
 	.set	kernbase,KERNBASE
+	.set    kernload,KERNLOAD
 	.set	dmapbase,DMAP_MIN_ADDRESS
 	.set	dmapend,DMAP_MAX_ADDRESS
 

Modified: head/sys/amd64/include/vmparam.h
==============================================================================
--- head/sys/amd64/include/vmparam.h	Wed Nov 25 23:17:23 2020	(r368040)
+++ head/sys/amd64/include/vmparam.h	Wed Nov 25 23:19:01 2020	(r368041)
@@ -149,6 +149,14 @@
 #endif
 
 /*
+ * Kernel physical load address. Needs to be aligned at 2MB superpage
+ * boundary.
+ */
+#ifndef KERNLOAD
+#define	KERNLOAD	0x200000
+#endif
+
+/*
  * Virtual addresses of things.  Derived from the page directory and
  * page table indexes from pmap.h for precision.
  *

Modified: head/sys/conf/ldscript.amd64
==============================================================================
--- head/sys/conf/ldscript.amd64	Wed Nov 25 23:17:23 2020	(r368040)
+++ head/sys/conf/ldscript.amd64	Wed Nov 25 23:19:01 2020	(r368041)
@@ -5,8 +5,8 @@ ENTRY(btext)
 SEARCH_DIR("/usr/lib");
 SECTIONS
 {
+  kernphys = kernload;
   /* Read-only sections, merged into text segment: */
-  kernphys = 0x200000; /* 2MB superpage size */
   . = kernbase + kernphys + SIZEOF_HEADERS;
   /*
    * Use the AT keyword in order to set the right LMA that contains