zipl/boot: use C pre-processor for linker script generation

Use C pre-processor for linker script generation and refactor some
constants. This allows the usage of the constants in our "linker
scripts" `*.lds.S` (actually, these are assembler files, so we can
make us of the C pre-processor and its capabilities).

While at it, enforce the described memory layout in the generated
linker script.

Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

include/boot/loaders_layout.h

@@ -14,19 +14,29 @@
 #include "lib/zt_common.h"
 #include "linux_layout.h"
 
+#define STAGE2_DESC			_AC(0x78, UL)
+#define STAGE2_ENTRY			_AC(0x2018, UL)
+#define STAGE2_HEAP_ADDRESS		_AC(0x6000, UL)
+#define STAGE2_HEAP_SIZE		_AC(0x3000, UL)
+#define STAGE2_STACK_ADDRESS		_AC(0xe400, UL)
+#define STAGE2_STACK_SIZE		_AC(0x1c00, UL)
+
 #define STAGE3_ENTRY			_AC(0xa000, UL)
 
 #define STAGE2_LOAD_ADDRESS		_AC(0x2000, UL)
 #define STAGE3_LOAD_ADDRESS		STAGE3_ENTRY
 #define IMAGE_LOAD_ADDRESS		IMAGE_ENTRY
 
+#define STAGE3_MAXIMUM_SIZE		_AC(0x3000, UL)
 #define STAGE3_HEAP_SIZE		_AC(0x4000, UL)
 #define STAGE3_HEAP_ADDRESS		_AC(0x2000, UL)
 #define STAGE3_STACK_SIZE		_AC(0x1000, UL)
 #define STAGE3_STACK_ADDRESS		_AC(0xF000, UL)
 #define STAGE3_PARAMS_ADDRESS		_AC(0x9000, UL)
+#define STAGE3_PARAMS_MAXIMUM_SIZE	_AC(0x1000, UL)
 
 #define COMMAND_LINE_EXTRA		_AC(0xE000, UL)
+#define COMMAND_LINE_EXTRA_SIZE		_AC(0x0400, UL)
 
 #ifndef __ASSEMBLER__
 #endif /* __ASSEMBLER__ */

zipl/boot/.gitignore

@@ -0,0 +1,2 @@
+*.lds
+*.lds.d

zipl/boot/Makefile

@@ -1,8 +1,11 @@
 # Common definitions
 include ../../common.mak
 
-ALL_CFLAGS = $(NO_PIE_CFLAGS) -Os -g -I $(rootdir)/zipl/include \
-	   -I $(rootdir)/include -DS390_TOOLS_RELEASE=$(S390_TOOLS_RELEASE) \
+INCLUDE_PATHS := $(rootdir)/zipl/include $(rootdir)/include
+INCLUDE_PARMS := $(addprefix -I,$(INCLUDE_PATHS))
+
+ALL_CFLAGS = $(NO_PIE_CFLAGS) -Os -g $(INCLUDE_PARMS) \
+	  -DS390_TOOLS_RELEASE=$(S390_TOOLS_RELEASE) \
 	  -fno-builtin -ffreestanding -fno-asynchronous-unwind-tables \
 	  -fno-delete-null-pointer-checks \
 	  -fexec-charset=IBM1047 -m64 -mpacked-stack \
@@ -26,6 +29,17 @@ all: data.o data.h tape0.bin stage3.bin
 %.o:	%.c
 	$(CC) $(ALL_CFLAGS) -c -o $@ $<
 
+# Dependencies for the .lds generation
+sources_lds_S = $(wildcard *.lds.S)
+dependencies_lds_S = $(sources_lds_S:%.lds.S=.%.lds.d)
+# Include all ".lds.d" dependency files for all make targets except for "clean"
+ifneq ($(MAKECMDGOALS),clean)
+-include $(dependencies_lds_S)
+endif
+
+%.lds: %.lds.S
+	$(CPP) -Wp,-MD,.$@.d,-MT,$@ $(INCLUDE_PARMS) -P -C -o $@ $<
+
 eckd2dump_sv.exec: \
 	head.o stage2dump.o cio.o eckd2dump.o eckd2dump_sv.o \
 	libc.o ebcdic.o sclp.o entry.o stage2.lds
@@ -104,6 +118,6 @@ data.h: data.o
 
 clean:
 	rm -f *.o *.exec *.bin $(FILES) data.o data.h tape0.bin *.xxx *.yyy \
-	      stage3.bin
+	      stage3.bin *.lds *.lds.d
 
 .PHONY: all clean

zipl/boot/stage2.c

@@ -15,6 +15,7 @@
 #include "libc.h"
 #include "menu.h"
 #include "boot/s390.h"
+#include "boot/loaders_layout.h"
 #include "stage2.h"
 
 static int is_null_descriptor(disk_blockptr_t *address)

zipl/boot/stage2.h

@@ -16,9 +16,6 @@
 
 #define DESCR_PER_BLOCK         _AC(16, U)
 
-/* ADRESS */
-#define STAGE2_DESC		_AC(0x78, UL)
-
 
 #ifndef __ASSEMBLER__
 

zipl/boot/stage2.lds.S

@@ -25,15 +25,19 @@
  * 0x5000-0x51ff	eckd2dump_mv parameter block (426 bytes)
  */
 
+#include "boot/loaders_layout.h"
+
 SECTIONS
 {
-  . = 0x78;
+  . = STAGE2_DESC;
   __stage2_desc = .;
 
-  . = 0x2000;
+  . = STAGE2_LOAD_ADDRESS;
   .stage2.head : { *(.stage2.head) }
-  . = 0x2018;
-  .text.start : { *(.text.start) }
+  . = STAGE2_ENTRY;
+  .text.start : {
+    *(.text.start)
+  }
   .text : { *(.text) }
   __ex_table_start = .;
   .ex_table : { *(.ex_table) }
@@ -52,12 +56,38 @@ SECTIONS
   .bss : { *(.bss) }
   __bss_stop = .;
 
-  . = 0x6000;
+  . = STAGE2_HEAP_ADDRESS;
   __heap_start = .;
-  . = 0x9000;
+  .heap : {
+    . += STAGE2_HEAP_SIZE;
+    ASSERT(__heap_stop - __heap_start == STAGE2_HEAP_SIZE,
+           "Heap section doesn't conform to the described memory layout");
+  }
   __heap_stop = .;
 
-  . = 0xf000;
+  /* Memory reserved for stage3. Use a dummy section to check if changes
+   * in stage3 memory layout work with stage2 and vice versa.
+   */
+  . = STAGE3_PARAMS_ADDRESS;
+  .stage3 : {
+    . += STAGE3_PARAMS_MAXIMUM_SIZE;
+
+    . = STAGE3_LOAD_ADDRESS - STAGE3_PARAMS_ADDRESS;
+    . += STAGE3_MAXIMUM_SIZE;
+
+    . = COMMAND_LINE_EXTRA - STAGE3_PARAMS_ADDRESS;
+    . += COMMAND_LINE_EXTRA_SIZE;
+  }
+
+  . = STAGE2_STACK_ADDRESS;
+  __stack_start = .;
+  .stack : {
+    . += STAGE2_STACK_SIZE;
+    ASSERT(__stack_end - __stack_start == STAGE2_STACK_SIZE,
+           "Stack section doesn't conform to the described memory layout");
+  }
+  __stack_end = .;
+
   .eh_frame : { *(.eh_frame) }
   .note.gnu.build-id : { *(.note.gnu.build-id) }
 }

zipl/boot/stage3.lds.S

@@ -13,21 +13,26 @@
  * 0xf000-0xffff        Stack
  */
 
+#include "boot/loaders_layout.h"
+
 SECTIONS
 {
   . = 0x0;
 
-  . = 0x2000;
+  . = STAGE3_HEAP_ADDRESS;
   __heap_start = .;
-  . = 0x6000;
+  .heap : {
+    . += STAGE3_HEAP_SIZE;
+    ASSERT(__heap_stop - __heap_start == STAGE3_HEAP_SIZE,
+           "Heap section doesn't conform to the described memory layout");
+  }
   __heap_stop = .;
 
-
   /* stage 3 parameter */
-  . = 0x9000;
+  . = STAGE3_PARAMS_ADDRESS;
   _stage3_parms = .;
 
-  . = 0xa000;
+  . = STAGE3_ENTRY;
   .text.start : { *(.text.start) }
   .text : { *(.text) }
   __ex_table_start = .;
@@ -40,4 +45,18 @@ SECTIONS
   __bss_stop = .;
   .rodata : {*(.rodata) }
   .data : { *(.data) }
+
+  . = COMMAND_LINE_EXTRA;
+  .cmdline_extra : {
+    . += COMMAND_LINE_EXTRA_SIZE;
+  }
+
+  . = STAGE3_STACK_ADDRESS;
+  __stack_start = .;
+  .stack : {
+    . += STAGE3_STACK_SIZE;
+    ASSERT(__stack_end - __stack_start == STAGE3_STACK_SIZE,
+           "Stack section doesn't conform to the described memory layout");
+  }
+  __stack_end = .;
 }