zipl: consolidate stage3_params structs and stage3 flags

Introduce a struct definition for the stage3 parameters used by
stage3.c. This makes it easier to maintain the stage3 linker script
and it allows us to consolidate the stage3_params structs defined in
`stage3.h` and `include/boot.h` as well as the stage3 flag macros.

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

zipl/boot/kdump3.c

@@ -100,9 +100,9 @@ void kdump_stage3(void)
 {
 	unsigned long crash_base, crash_size;
 
-	if (!(stage3_flags & STAGE3_FLAG_KDUMP))
+	if (!(_stage3_parms.flags & STAGE3_FLAG_KDUMP))
 		return;
-	if (!(stage3_flags & STAGE3_FLAG_SCSI))
+	if (!(_stage3_parms.flags & STAGE3_FLAG_SCSI))
 		kdump_stage3_dasd(&crash_base, &crash_size);
 	else
 		kdump_stage3_scsi(&crash_base, &crash_size);

zipl/boot/stage3.c

@@ -147,19 +147,19 @@ void start(void)
 	 * verified component. If it is not IPL is aborted.
 	 */
 	if (secure_boot_enabled()) {
-		if (_image_addr != IMAGE_LOAD_ADDRESS ||
-		    _load_psw != DEFAULT_PSW_LOAD)
+		if (_stage3_parms.image_addr != IMAGE_LOAD_ADDRESS ||
+		    _stage3_parms.load_psw != DEFAULT_PSW_LOAD)
 			panic(ESECUREBOOT, "%s", msg_sipl_inval);
 
-		if (!is_verified_address(_load_psw & PSW_ADDR_MASK))
+		if (!is_verified_address(_stage3_parms.load_psw & PSW_ADDR_MASK))
 			panic(ESECUREBOOT, "%s", msg_sipl_unverified);
 	}
 	/*
 	 * cut the kernel header
 	 */
-	memmove((void *)_image_addr,
-		(void *)_image_addr + IMAGE_LOAD_ADDRESS,
-		_image_len - IMAGE_LOAD_ADDRESS);
+	memmove((void *)_stage3_parms.image_addr,
+		(void *)_stage3_parms.image_addr + IMAGE_LOAD_ADDRESS,
+		_stage3_parms.image_len - IMAGE_LOAD_ADDRESS);
 
 	/* store subchannel ID into low core and into new kernel space */
 	subchannel_id = S390_lowcore.subchannel_id;
@@ -167,15 +167,16 @@ void start(void)
 	*(unsigned long long *)IPL_DEVICE = subchannel_id;
 
 	/* if valid command line is given, copy it into new kernel space */
-	if (_parm_addr != UNSPECIFIED_ADDRESS) {
+	if (_stage3_parms.parm_addr != UNSPECIFIED_ADDRESS) {
 		memcpy((void *)COMMAND_LINE,
-		       (void *)(unsigned long *)_parm_addr, COMMAND_LINE_SIZE);
+		       (void *)(unsigned long *)_stage3_parms.parm_addr,
+		       COMMAND_LINE_SIZE);
 		/* terminate \0 */
 		*(char *)(COMMAND_LINE + COMMAND_LINE_SIZE - 1) = 0;
 	}
 
 	/* convert extra parameter to ascii */
-	if (!_extra_parm || !*cextra)
+	if (!_stage3_parms.extra_parm || !*cextra)
 		goto noextra;
 
 	/* Handle extra kernel parameters specified in DASD boot menu. */
@@ -216,11 +217,11 @@ void start(void)
 
 noextra:
 	/* copy initrd start address and size intop new kernle space */
-	*(unsigned long long *)INITRD_START = _initrd_addr;
-	*(unsigned long long *)INITRD_SIZE = _initrd_len;
+	*(unsigned long long *)INITRD_START = _stage3_parms.initrd_addr;
+	*(unsigned long long *)INITRD_SIZE = _stage3_parms.initrd_len;
 
 	/* store address of new kernel to 0 to be able to start it */
-	*(unsigned long long *)0 = _load_psw;
+	*(unsigned long long *)0 = _stage3_parms.load_psw;
 
 	kdump_stage3();
 

zipl/boot/stage3.h

@@ -12,6 +12,7 @@
 #ifndef STAGE3_H
 #define STAGE3_H
 
+#include "lib/zt_common.h"
 #include "boot/s390.h"
 #include "boot/ipl.h"
 #include "boot/linux_layout.h"
@@ -27,15 +28,21 @@
 
 #define UNSPECIFIED_ADDRESS		-1UL
 
+/* Stage 3 bootloader parameter structure */
+/* Structure must not have any padding */
+struct stage3_parms {
+	unsigned long long parm_addr;   /* address of parmline */
+	unsigned long long initrd_addr; /* address of initrd */
+	unsigned long long initrd_len;  /* length of initrd */
+	unsigned long long load_psw;    /*  load psw of kernel */
+	unsigned long long extra_parm;  /* use extra parm line mechanism? */
+	unsigned long long flags;       /* flags (e.g. STAGE3_FLAG_KDUMP) */
+	unsigned long long image_len;   /* length of kernel */
+	unsigned long long image_addr;  /* target address of kernel */
+};
+STATIC_ASSERT(sizeof(struct stage3_parms) == 8 * 8)
 
-extern unsigned long long _parm_addr;   /* address of parmline */
-extern unsigned long long _initrd_addr; /* address of initrd */
-extern unsigned long long _initrd_len;  /* length of initrd */
-extern unsigned long long _load_psw;    /*  load psw of kernel */
-extern unsigned long long _extra_parm;  /* use extra parm line mechanism? */
-extern unsigned long long stage3_flags; /*  flags (e.g. STAGE3_FLAG_KDUMP) */
-extern unsigned long long _image_len;   /* length of kernel */
-extern unsigned long long _image_addr;  /* target address of kernel */
+extern struct stage3_parms _stage3_parms;
 extern void kdump_stage3();
 
 #endif /* STAGE3_H */

zipl/boot/stage3.lds

@@ -25,21 +25,7 @@ SECTIONS
 
   /* stage 3 parameter */
   . = 0x9000;
-  _parm_addr = .;
-  . = 0x9008;
-  _initrd_addr = .;
-  . = 0x9010;
-  _initrd_len = .;
-  . = 0x9018;
-  _load_psw = .;
-  . = 0x9020;
-  _extra_parm = .;
-  . = 0x9028;
-  stage3_flags =.;
-  . = 0x9030;
-  _image_len = .;
-  . = 0x9038;
-  _image_addr = .;
+  _stage3_parms = .;
 
   . = 0xa000;
   .text.start : { *(.text.start) }

zipl/include/boot.h

@@ -241,23 +241,6 @@ struct boot_stage2_params {
 } __packed;
 
 
-/* Stage 3 bootloader parameter structure */
-
-struct boot_stage3_params {
-	uint64_t parm_addr;
-	uint64_t initrd_addr;
-	uint64_t initrd_len;
-	uint64_t load_psw;
-	uint64_t extra_parm;
-	uint16_t flags;
-	uint16_t reserved[3];
-	uint64_t image_len;
-	uint64_t image_addr;
-} __packed;
-
-#define STAGE3_FLAG_SCSI		0x0001
-#define STAGE3_FLAG_KDUMP		0x0002
-
 /* Tape IPL bootloader parameter structure */
 
 #define BOOT_TAPE_IPL_PARAMS_OFFSET	0x200
@@ -312,7 +295,7 @@ int boot_init_fba_stage1b(struct boot_fba_stage1b *stage1b,
 int boot_get_eckd_stage2(void** data, size_t* size, struct job_data* job);
 int boot_get_stage3_parms(void **buffer, size_t *bytecount, address_t parm_addr,
 			  address_t initrd_addr, size_t initrd_len,
-			  address_t entry, int extra_parm, uint16_t flags,
+			  address_t entry, int extra_parm, uint64_t flags,
 			  address_t image_addr, size_t image_len);
 int boot_get_tape_ipl(void** data, size_t* size, address_t parm_addr,
 		      address_t initrd_addr, address_t image_addr);

zipl/src/boot.c

@@ -17,6 +17,8 @@
 #include <fcntl.h>
 #include <sys/stat.h>
 
+#include "stage3.h"
+
 #include "../boot/data.h"
 #include "boot.h"
 #include "bootmap.h"
@@ -79,10 +81,10 @@ boot_check_data(void)
 int
 boot_get_stage3_parms(void **buffer, size_t *bytecount, address_t parm_addr,
 		      address_t initrd_addr, size_t initrd_len,
-		      address_t entry, int extra_parm, uint16_t flags,
+		      address_t entry, int extra_parm, uint64_t flags,
 		      address_t image_addr, size_t image_len)
 {
-	struct boot_stage3_params params;
+	struct stage3_parms params;
 	void* data;
 
 	if (entry != (entry & PSW_ADDRESS_MASK)) {

zipl/src/bootmap.c

@@ -21,6 +21,7 @@
 #include "lib/zt_common.h"
 #include "lib/util_part.h"
 #include "lib/util_path.h"
+#include "stage3.h"
 
 #include "boot.h"
 #include "bootmap.h"