OvmfPkg: introduce the FD_SIZE_IN_KB macro / build flag

FD_SIZE_xMB defines have existed for flash size selection. They can be
passed as "-D FD_SIZE_xMB" on the command line. Passing multiple of them
at the same time has never been supported; earlier settings on the command
line cannot be overridden.

Introduce the integer valued FD_SIZE_IN_KB macro, which provides the
following improvements:

- several instances of it are permitted on the command line, with the last
  one taking effect,

- conditional statements in the DSC and FDF files need only check a single
  macro, and multiple values can be checked in a single !if with the ||
  operator,

- nested !ifdef / !else ladders can be replaced with flat equality tests,

- in the future, flash sizes can be expressed with a finer than MB
  granularity, if necessary.

For now, we're going to preserve the FD_SIZE_xMB defines as convenience
wrappers for FD_SIZE_IN_KB.

FD_SIZE_IN_KB is being added to the DSC files because this way we can
depend on it in both the DSC and FDF files.

Cc: Gary Ching-Pang Lin <glin@suse.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

OvmfPkg/OvmfPkg.fdf.inc

@@ -15,18 +15,11 @@
 #
 ##
 
-#
-# Default flash size is 2MB.
-#
-# Defining FD_SIZE_1MB on the build command line can override this.
-#
-
 DEFINE BLOCK_SIZE        = 0x1000
 DEFINE VARS_SIZE         = 0x20000
 DEFINE VARS_BLOCKS       = 0x20
 
-!ifdef $(FD_SIZE_1MB)
-
+!if $(FD_SIZE_IN_KB) == 1024
 DEFINE FW_BASE_ADDRESS   = 0xFFF00000
 DEFINE FW_SIZE           = 0x00100000
 DEFINE FW_BLOCKS         = 0x100
@@ -36,9 +29,9 @@ DEFINE CODE_BLOCKS       = 0xE0
 DEFINE FVMAIN_SIZE       = 0x000CC000
 DEFINE SECFV_OFFSET      = 0x000EC000
 DEFINE SECFV_SIZE        = 0x14000
+!endif
 
-!else
-
+!if $(FD_SIZE_IN_KB) == 2048
 DEFINE FW_BASE_ADDRESS   = 0xFFE00000
 DEFINE FW_SIZE           = 0x00200000
 DEFINE FW_BLOCKS         = 0x200
@@ -48,7 +41,6 @@ DEFINE CODE_BLOCKS       = 0x1E0
 DEFINE FVMAIN_SIZE       = 0x001AC000
 DEFINE SECFV_OFFSET      = 0x001CC000
 DEFINE SECFV_SIZE        = 0x34000
-
 !endif
 
 SET gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFdBaseAddress     = $(FW_BASE_ADDRESS)

OvmfPkg/OvmfPkgIa32.dsc

@@ -40,6 +40,21 @@
   DEFINE SMM_REQUIRE             = FALSE
   DEFINE TLS_ENABLE              = FALSE
 
+  #
+  # Flash size selection. Setting FD_SIZE_IN_KB on the command line directly to
+  # one of the supported values, in place of any of the convenience macros, is
+  # permitted.
+  #
+!ifdef $(FD_SIZE_1MB)
+  DEFINE FD_SIZE_IN_KB           = 1024
+!else
+!ifdef $(FD_SIZE_2MB)
+  DEFINE FD_SIZE_IN_KB           = 2048
+!else
+  DEFINE FD_SIZE_IN_KB           = 2048
+!endif
+!endif
+
 [BuildOptions]
   GCC:*_UNIXGCC_*_CC_FLAGS             = -DMDEPKG_NDEBUG
   GCC:RELEASE_*_*_CC_FLAGS             = -DMDEPKG_NDEBUG

OvmfPkg/OvmfPkgIa32X64.dsc

@@ -40,6 +40,21 @@
   DEFINE SMM_REQUIRE             = FALSE
   DEFINE TLS_ENABLE              = FALSE
 
+  #
+  # Flash size selection. Setting FD_SIZE_IN_KB on the command line directly to
+  # one of the supported values, in place of any of the convenience macros, is
+  # permitted.
+  #
+!ifdef $(FD_SIZE_1MB)
+  DEFINE FD_SIZE_IN_KB           = 1024
+!else
+!ifdef $(FD_SIZE_2MB)
+  DEFINE FD_SIZE_IN_KB           = 2048
+!else
+  DEFINE FD_SIZE_IN_KB           = 2048
+!endif
+!endif
+
 [BuildOptions]
   GCC:*_UNIXGCC_*_CC_FLAGS             = -DMDEPKG_NDEBUG
   GCC:RELEASE_*_*_CC_FLAGS             = -DMDEPKG_NDEBUG

OvmfPkg/OvmfPkgX64.dsc

@@ -40,6 +40,21 @@
   DEFINE SMM_REQUIRE             = FALSE
   DEFINE TLS_ENABLE              = FALSE
 
+  #
+  # Flash size selection. Setting FD_SIZE_IN_KB on the command line directly to
+  # one of the supported values, in place of any of the convenience macros, is
+  # permitted.
+  #
+!ifdef $(FD_SIZE_1MB)
+  DEFINE FD_SIZE_IN_KB           = 1024
+!else
+!ifdef $(FD_SIZE_2MB)
+  DEFINE FD_SIZE_IN_KB           = 2048
+!else
+  DEFINE FD_SIZE_IN_KB           = 2048
+!endif
+!endif
+
 [BuildOptions]
   GCC:*_UNIXGCC_*_CC_FLAGS             = -DMDEPKG_NDEBUG
   GCC:RELEASE_*_*_CC_FLAGS             = -DMDEPKG_NDEBUG