xref: /openbmc/linux/arch/s390/boot/head.S (revision 48cc39c3)
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright IBM Corp. 1999, 2010
4 *
5 *    Author(s): Hartmut Penner <hp@de.ibm.com>
6 *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
7 *		 Rob van der Heij <rvdhei@iae.nl>
8 *		 Heiko Carstens <heiko.carstens@de.ibm.com>
9 *
10 * There are 5 different IPL methods
11 *  1) load the image directly into ram at address 0 and do an PSW restart
12 *  2) linload will load the image from address 0x10000 to memory 0x10000
13 *     and start the code thru LPSW 0x0008000080010000 (VM only, deprecated)
14 *  3) generate the tape ipl header, store the generated image on a tape
15 *     and ipl from it
16 *     In case of SL tape you need to IPL 5 times to get past VOL1 etc
17 *  4) generate the vm reader ipl header, move the generated image to the
18 *     VM reader (use option NOH!) and do a ipl from reader (VM only)
19 *  5) direct call of start by the SALIPL loader
20 *  We use the cpuid to distinguish between VM and native ipl
21 *  params for kernel are pushed to 0x10400 (see setup.h)
22 *
23 */
24
25#include <linux/init.h>
26#include <linux/linkage.h>
27#include <asm/asm-offsets.h>
28#include <asm/page.h>
29#include <asm/ptrace.h>
30#include <asm/sclp.h>
31
32#define ARCH_OFFSET	4
33
34#define EP_OFFSET	0x10008
35#define EP_STRING	"S390EP"
36
37__HEAD
38
39#define IPL_BS	0x730
40	.org	0
41	.long	0x00080000,0x80000000+iplstart	# The first 24 bytes are loaded
42	.long	0x02000018,0x60000050		# by ipl to addresses 0-23.
43	.long	0x02000068,0x60000050		# (a PSW and two CCWs).
44	.fill	80-24,1,0x40			# bytes 24-79 are discarded !!
45	.long	0x020000f0,0x60000050		# The next 160 byte are loaded
46	.long	0x02000140,0x60000050		# to addresses 0x18-0xb7
47	.long	0x02000190,0x60000050		# They form the continuation
48	.long	0x020001e0,0x60000050		# of the CCW program started
49	.long	0x02000230,0x60000050		# by ipl and load the range
50	.long	0x02000280,0x60000050		# 0x0f0-0x730 from the image
51	.long	0x020002d0,0x60000050		# to the range 0x0f0-0x730
52	.long	0x02000320,0x60000050		# in memory. At the end of
53	.long	0x02000370,0x60000050		# the channel program the PSW
54	.long	0x020003c0,0x60000050		# at location 0 is loaded.
55	.long	0x02000410,0x60000050		# Initial processing starts
56	.long	0x02000460,0x60000050		# at 0x200 = iplstart.
57	.long	0x020004b0,0x60000050
58	.long	0x02000500,0x60000050
59	.long	0x02000550,0x60000050
60	.long	0x020005a0,0x60000050
61	.long	0x020005f0,0x60000050
62	.long	0x02000640,0x60000050
63	.long	0x02000690,0x60000050
64	.long	0x020006e0,0x20000050
65
66	.org	__LC_RST_NEW_PSW		# 0x1a0
67	.quad	0,iplstart
68	.org	__LC_EXT_NEW_PSW		# 0x1b0
69	.quad	0x0002000180000000,0x1b0	# disabled wait
70	.org	__LC_PGM_NEW_PSW		# 0x1d0
71	.quad	0x0000000180000000,startup_pgm_check_handler
72	.org	__LC_IO_NEW_PSW			# 0x1f0
73	.quad	0x0002000180000000,0x1f0	# disabled wait
74
75	.org	0x200
76
77#
78# subroutine to wait for end I/O
79#
80.Lirqwait:
81	mvc	__LC_IO_NEW_PSW(16),.Lnewpsw	# set up IO interrupt psw
82	lpsw	.Lwaitpsw
83.Lioint:
84	br	%r14
85	.align	8
86.Lnewpsw:
87	.quad	0x0000000080000000,.Lioint
88.Lwaitpsw:
89	.long	0x020a0000,0x80000000+.Lioint
90
91#
92# subroutine for loading cards from the reader
93#
94.Lloader:
95	la	%r4,0(%r14)
96	la	%r3,.Lorb		# r2 = address of orb into r2
97	la	%r5,.Lirb		# r4 = address of irb
98	la	%r6,.Lccws
99	la	%r7,20
100.Linit:
101	st	%r2,4(%r6)		# initialize CCW data addresses
102	la	%r2,0x50(%r2)
103	la	%r6,8(%r6)
104	bct	7,.Linit
105
106	lctl	%c6,%c6,.Lcr6		# set IO subclass mask
107	slr	%r2,%r2
108.Lldlp:
109	ssch	0(%r3)			# load chunk of 1600 bytes
110	bnz	.Llderr
111.Lwait4irq:
112	bas	%r14,.Lirqwait
113	c	%r1,__LC_SUBCHANNEL_ID	# compare subchannel number
114	bne	.Lwait4irq
115	tsch	0(%r5)
116
117	slr	%r0,%r0
118	ic	%r0,8(%r5)		# get device status
119	chi	%r0,8			# channel end ?
120	be	.Lcont
121	chi	%r0,12			# channel end + device end ?
122	be	.Lcont
123
124	l	%r0,4(%r5)
125	s	%r0,8(%r3)		# r0/8 = number of ccws executed
126	mhi	%r0,10			# *10 = number of bytes in ccws
127	lh	%r3,10(%r5)		# get residual count
128	sr	%r0,%r3 		# #ccws*80-residual=#bytes read
129	ar	%r2,%r0
130
131	br	%r4			# r2 contains the total size
132
133.Lcont:
134	ahi	%r2,0x640		# add 0x640 to total size
135	la	%r6,.Lccws
136	la	%r7,20
137.Lincr:
138	l	%r0,4(%r6)		# update CCW data addresses
139	ahi	%r0,0x640
140	st	%r0,4(%r6)
141	ahi	%r6,8
142	bct	7,.Lincr
143
144	b	.Lldlp
145.Llderr:
146	lpsw	.Lcrash
147
148	.align	8
149.Lorb:	.long	0x00000000,0x0080ff00,.Lccws
150.Lirb:	.long	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
151.Lcr6:	.long	0xff000000
152.Lloadp:.long	0,0
153	.align	8
154.Lcrash:.long	0x000a0000,0x00000000
155
156	.align	8
157.Lccws: .rept	19
158	.long	0x02600050,0x00000000
159	.endr
160	.long	0x02200050,0x00000000
161
162iplstart:
163	mvi	__LC_AR_MODE_ID,1	# set esame flag
164	slr	%r0,%r0			# set cpuid to zero
165	lhi	%r1,2			# mode 2 = esame (dump)
166	sigp	%r1,%r0,0x12		# switch to esame mode
167	bras	%r13,0f
168	.fill	16,4,0x0
1690:	lmh	%r0,%r15,0(%r13)	# clear high-order half of gprs
170	sam31				# switch to 31 bit addressing mode
171	lh	%r1,__LC_SUBCHANNEL_ID	# test if subchannel number
172	bct	%r1,.Lnoload		#  is valid
173	l	%r1,__LC_SUBCHANNEL_ID	# load ipl subchannel number
174	la	%r2,IPL_BS		# load start address
175	bas	%r14,.Lloader		# load rest of ipl image
176	l	%r12,.Lparm		# pointer to parameter area
177	st	%r1,IPL_DEVICE+ARCH_OFFSET-PARMAREA(%r12) # save ipl device number
178
179#
180# load parameter file from ipl device
181#
182.Lagain1:
183	l	%r2,.Linitrd		# ramdisk loc. is temp
184	bas	%r14,.Lloader		# load parameter file
185	ltr	%r2,%r2 		# got anything ?
186	bz	.Lnopf
187	chi	%r2,895
188	bnh	.Lnotrunc
189	la	%r2,895
190.Lnotrunc:
191	l	%r4,.Linitrd
192	clc	0(3,%r4),.L_hdr		# if it is HDRx
193	bz	.Lagain1		# skip dataset header
194	clc	0(3,%r4),.L_eof		# if it is EOFx
195	bz	.Lagain1		# skip dateset trailer
196	la	%r5,0(%r4,%r2)
197	lr	%r3,%r2
198	la	%r3,COMMAND_LINE-PARMAREA(%r12) # load adr. of command line
199	mvc	0(256,%r3),0(%r4)
200	mvc	256(256,%r3),256(%r4)
201	mvc	512(256,%r3),512(%r4)
202	mvc	768(122,%r3),768(%r4)
203	slr	%r0,%r0
204	b	.Lcntlp
205.Ldelspc:
206	ic	%r0,0(%r2,%r3)
207	chi	%r0,0x20		# is it a space ?
208	be	.Lcntlp
209	ahi	%r2,1
210	b	.Leolp
211.Lcntlp:
212	brct	%r2,.Ldelspc
213.Leolp:
214	slr	%r0,%r0
215	stc	%r0,0(%r2,%r3)		# terminate buffer
216.Lnopf:
217
218#
219# load ramdisk from ipl device
220#
221.Lagain2:
222	l	%r2,.Linitrd		# addr of ramdisk
223	st	%r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
224	bas	%r14,.Lloader		# load ramdisk
225	st	%r2,INITRD_SIZE+ARCH_OFFSET-PARMAREA(%r12) # store size of rd
226	ltr	%r2,%r2
227	bnz	.Lrdcont
228	st	%r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # no ramdisk found
229.Lrdcont:
230	l	%r2,.Linitrd
231
232	clc	0(3,%r2),.L_hdr		# skip HDRx and EOFx
233	bz	.Lagain2
234	clc	0(3,%r2),.L_eof
235	bz	.Lagain2
236
237#
238# reset files in VM reader
239#
240	stidp	.Lcpuid			# store cpuid
241	tm	.Lcpuid,0xff		# running VM ?
242	bno	.Lnoreset
243	la	%r2,.Lreset
244	lhi	%r3,26
245	diag	%r2,%r3,8
246	la	%r5,.Lirb
247	stsch	0(%r5)			# check if irq is pending
248	tm	30(%r5),0x0f		# by verifying if any of the
249	bnz	.Lwaitforirq		# activity or status control
250	tm	31(%r5),0xff		# bits is set in the schib
251	bz	.Lnoreset
252.Lwaitforirq:
253	bas	%r14,.Lirqwait		# wait for IO interrupt
254	c	%r1,__LC_SUBCHANNEL_ID	# compare subchannel number
255	bne	.Lwaitforirq
256	la	%r5,.Lirb
257	tsch	0(%r5)
258.Lnoreset:
259	b	.Lnoload
260
261#
262# everything loaded, go for it
263#
264.Lnoload:
265	l	%r1,.Lstartup
266	br	%r1
267
268.Linitrd:.long _end			# default address of initrd
269.Lparm:	.long  PARMAREA
270.Lstartup: .long startup
271.Lreset:.byte	0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
272	.byte	0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
273	.byte	0xc8,0xd6,0xd3,0xc4	# "change rdr all keep nohold"
274.L_eof: .long	0xc5d6c600	 /* C'EOF' */
275.L_hdr: .long	0xc8c4d900	 /* C'HDR' */
276	.align	8
277.Lcpuid:.fill	8,1,0
278
279#
280# normal startup-code, running in absolute addressing mode
281# this is called either by the ipl loader or directly by PSW restart
282# or linload or SALIPL
283#
284	.org	STARTUP_NORMAL_OFFSET
285SYM_CODE_START(startup)
286	j	startup_normal
287	.org	EP_OFFSET
288#
289# This is a list of s390 kernel entry points. At address 0x1000f the number of
290# valid entry points is stored.
291#
292# IMPORTANT: Do not change this table, it is s390 kernel ABI!
293#
294	.ascii	EP_STRING
295	.byte	0x00,0x01
296#
297# kdump startup-code, running in 64 bit absolute addressing mode
298#
299	.org	STARTUP_KDUMP_OFFSET
300	j	startup_kdump
301SYM_CODE_END(startup)
302SYM_CODE_START_LOCAL(startup_normal)
303	mvi	__LC_AR_MODE_ID,1	# set esame flag
304	slr	%r0,%r0 		# set cpuid to zero
305	lhi	%r1,2			# mode 2 = esame (dump)
306	sigp	%r1,%r0,0x12		# switch to esame mode
307	bras	%r13,0f
308	.fill	16,4,0x0
3090:	lmh	%r0,%r15,0(%r13)	# clear high-order half of gprs
310	sam64				# switch to 64 bit addressing mode
311	basr	%r13,0			# get base
312.LPG0:
313	mvc	__LC_EXT_NEW_PSW(16),.Lext_new_psw-.LPG0(%r13)
314	mvc	__LC_PGM_NEW_PSW(16),.Lpgm_new_psw-.LPG0(%r13)
315	mvc	__LC_IO_NEW_PSW(16),.Lio_new_psw-.LPG0(%r13)
316	xc	0x200(256),0x200	# partially clear lowcore
317	xc	0x300(256),0x300
318	xc	0xe00(256),0xe00
319	xc	0xf00(256),0xf00
320	stcke	__LC_BOOT_CLOCK
321	mvc	__LC_LAST_UPDATE_CLOCK(8),__LC_BOOT_CLOCK+1
322	spt	6f-.LPG0(%r13)
323	mvc	__LC_LAST_UPDATE_TIMER(8),6f-.LPG0(%r13)
324	larl	%r15,_stack_end-STACK_FRAME_OVERHEAD
325	brasl	%r14,sclp_early_setup_buffer
326	brasl	%r14,verify_facilities
327	brasl	%r14,startup_kernel
328SYM_CODE_END(startup_normal)
329
330	.align	8
3316:	.long	0x7fffffff,0xffffffff
332.Lext_new_psw:
333	.quad	0x0002000180000000,0x1b0	# disabled wait
334.Lpgm_new_psw:
335	.quad	0x0000000180000000,startup_pgm_check_handler
336.Lio_new_psw:
337	.quad	0x0002000180000000,0x1f0	# disabled wait
338
339#include "head_kdump.S"
340
341#
342# This program check is active immediately after kernel start
343# and until early_pgm_check_handler is set in kernel/early.c
344# It simply saves general/control registers and psw in
345# the save area and does disabled wait with a faulty address.
346#
347SYM_CODE_START_LOCAL(startup_pgm_check_handler)
348	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
349	la	%r8,4095
350	stctg	%c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r8)
351	stmg	%r0,%r7,__LC_GPREGS_SAVE_AREA-4095(%r8)
352	mvc	__LC_GPREGS_SAVE_AREA-4095+64(64,%r8),__LC_SAVE_AREA_SYNC
353	mvc	__LC_PSW_SAVE_AREA-4095(16,%r8),__LC_PGM_OLD_PSW
354	mvc	__LC_RETURN_PSW(16),__LC_PGM_OLD_PSW
355	ni	__LC_RETURN_PSW,0xfc	# remove IO and EX bits
356	ni	__LC_RETURN_PSW+1,0xfb	# remove MCHK bit
357	oi	__LC_RETURN_PSW+1,0x2	# set wait state bit
358	larl	%r9,.Lold_psw_disabled_wait
359	stg	%r9,__LC_PGM_NEW_PSW+8
360	larl	%r15,_dump_info_stack_end-STACK_FRAME_OVERHEAD
361	brasl	%r14,print_pgm_check_info
362.Lold_psw_disabled_wait:
363	la	%r8,4095
364	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r8)
365	lpswe	__LC_RETURN_PSW		# disabled wait
366SYM_CODE_END(startup_pgm_check_handler)
367
368#
369# params at 10400 (setup.h)
370# Must be keept in sync with struct parmarea in setup.h
371#
372	.org	PARMAREA
373SYM_DATA_START(parmarea)
374	.quad	0			# IPL_DEVICE
375	.quad	0			# INITRD_START
376	.quad	0			# INITRD_SIZE
377	.quad	0			# OLDMEM_BASE
378	.quad	0			# OLDMEM_SIZE
379	.quad	kernel_version		# points to kernel version string
380
381	.org	COMMAND_LINE
382	.byte	"root=/dev/ram0 ro"
383	.byte	0
384	.org	PARMAREA+__PARMAREA_SIZE
385SYM_DATA_END(parmarea)
386
387	.org	HEAD_END
388