xref: /openbmc/linux/arch/s390/boot/head.S (revision aceb06d1)
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 *
9 * There are 5 different IPL methods
10 *  1) load the image directly into ram at address 0 and do an PSW restart
11 *  2) linload will load the image from address 0x10000 to memory 0x10000
12 *     and start the code thru LPSW 0x0008000080010000 (VM only, deprecated)
13 *  3) generate the tape ipl header, store the generated image on a tape
14 *     and ipl from it
15 *     In case of SL tape you need to IPL 5 times to get past VOL1 etc
16 *  4) generate the vm reader ipl header, move the generated image to the
17 *     VM reader (use option NOH!) and do a ipl from reader (VM only)
18 *  5) direct call of start by the SALIPL loader
19 *  We use the cpuid to distinguish between VM and native ipl
20 *  params for kernel are pushed to 0x10400 (see setup.h)
21 *
22 */
23
24#include <linux/init.h>
25#include <linux/linkage.h>
26#include <asm/asm-offsets.h>
27#include <asm/page.h>
28#include <asm/ptrace.h>
29#include <asm/sclp.h>
30
31#define ARCH_OFFSET	4
32
33#define EP_OFFSET	0x10008
34#define EP_STRING	"S390EP"
35
36#define IPL_START	0x200
37
38__HEAD
39
40#define IPL_BS	0x730
41	.org	0
42	.long	0x00080000,0x80000000+IPL_START	# The first 24 bytes are loaded
43	.long	0x02000018,0x60000050		# by ipl to addresses 0-23.
44	.long	0x02000068,0x60000050		# (a PSW and two CCWs).
45	.fill	80-24,1,0x40			# bytes 24-79 are discarded !!
46	.long	0x020000f0,0x60000050		# The next 160 byte are loaded
47	.long	0x02000140,0x60000050		# to addresses 0x18-0xb7
48	.long	0x02000190,0x60000050		# They form the continuation
49	.long	0x020001e0,0x60000050		# of the CCW program started
50	.long	0x02000230,0x60000050		# by ipl and load the range
51	.long	0x02000280,0x60000050		# 0x0f0-0x730 from the image
52	.long	0x020002d0,0x60000050		# to the range 0x0f0-0x730
53	.long	0x02000320,0x60000050		# in memory. At the end of
54	.long	0x02000370,0x60000050		# the channel program the PSW
55	.long	0x020003c0,0x60000050		# at location 0 is loaded.
56	.long	0x02000410,0x60000050		# Initial processing starts
57	.long	0x02000460,0x60000050		# at 0x200 = iplstart.
58	.long	0x020004b0,0x60000050
59	.long	0x02000500,0x60000050
60	.long	0x02000550,0x60000050
61	.long	0x020005a0,0x60000050
62	.long	0x020005f0,0x60000050
63	.long	0x02000640,0x60000050
64	.long	0x02000690,0x60000050
65	.long	0x020006e0,0x20000050
66
67# The restart psw points to ipl_entry, which allows to load a kernel image
68# into memory and starting it by a psw restart on any cpu.
69# All other default psw new locations contain a disabled wait psw where the
70# address indicates which psw was loaded.
71	.org	__LC_RST_NEW_PSW
72	.quad	0,IPL_START
73	.org	__LC_EXT_NEW_PSW
74	.quad	0x0002000180000000,__LC_EXT_NEW_PSW
75	.org	__LC_SVC_NEW_PSW
76	.quad	0x0002000180000000,__LC_SVC_NEW_PSW
77	.org	__LC_PGM_NEW_PSW
78	.quad	0x0002000180000000,__LC_PGM_NEW_PSW
79	.org	__LC_MCK_NEW_PSW
80	.quad	0x0002000180000000,__LC_MCK_NEW_PSW
81	.org	__LC_IO_NEW_PSW
82	.quad	0x0002000180000000,__LC_IO_NEW_PSW
83
84	.org	IPL_START
85ipl_start:
86	j	.Liplcont
87#
88# subroutine to wait for end I/O
89#
90.Lirqwait:
91	mvc	__LC_IO_NEW_PSW(16),.Lnewpsw	# set up IO interrupt psw
92	lpsw	.Lwaitpsw
93.Lioint:
94	br	%r14
95	.align	8
96.Lnewpsw:
97	.quad	0x0000000080000000,.Lioint
98.Lwaitpsw:
99	.long	0x020a0000,0x80000000+.Lioint
100
101#
102# subroutine for loading cards from the reader
103#
104.Lloader:
105	la	%r4,0(%r14)
106	la	%r3,.Lorb		# r2 = address of orb into r2
107	la	%r5,.Lirb		# r4 = address of irb
108	la	%r6,.Lccws
109	la	%r7,20
110.Linit:
111	st	%r2,4(%r6)		# initialize CCW data addresses
112	la	%r2,0x50(%r2)
113	la	%r6,8(%r6)
114	bct	7,.Linit
115
116	lctl	%c6,%c6,.Lcr6		# set IO subclass mask
117	slr	%r2,%r2
118.Lldlp:
119	ssch	0(%r3)			# load chunk of 1600 bytes
120	bnz	.Llderr
121.Lwait4irq:
122	bas	%r14,.Lirqwait
123	c	%r1,__LC_SUBCHANNEL_ID	# compare subchannel number
124	bne	.Lwait4irq
125	tsch	0(%r5)
126
127	slr	%r0,%r0
128	ic	%r0,8(%r5)		# get device status
129	chi	%r0,8			# channel end ?
130	be	.Lcont
131	chi	%r0,12			# channel end + device end ?
132	be	.Lcont
133
134	l	%r0,4(%r5)
135	s	%r0,8(%r3)		# r0/8 = number of ccws executed
136	mhi	%r0,10			# *10 = number of bytes in ccws
137	lh	%r3,10(%r5)		# get residual count
138	sr	%r0,%r3 		# #ccws*80-residual=#bytes read
139	ar	%r2,%r0
140
141	br	%r4			# r2 contains the total size
142
143.Lcont:
144	ahi	%r2,0x640		# add 0x640 to total size
145	la	%r6,.Lccws
146	la	%r7,20
147.Lincr:
148	l	%r0,4(%r6)		# update CCW data addresses
149	ahi	%r0,0x640
150	st	%r0,4(%r6)
151	ahi	%r6,8
152	bct	7,.Lincr
153
154	b	.Lldlp
155.Llderr:
156	lpsw	.Lcrash
157
158	.align	8
159.Lorb:	.long	0x00000000,0x0080ff00,.Lccws
160.Lirb:	.long	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
161.Lcr6:	.long	0xff000000
162.Lloadp:.long	0,0
163	.align	8
164.Lcrash:.long	0x000a0000,0x00000000
165
166	.align	8
167.Lccws: .rept	19
168	.long	0x02600050,0x00000000
169	.endr
170	.long	0x02200050,0x00000000
171
172.Liplcont:
173	mvi	__LC_AR_MODE_ID,1	# set esame flag
174	slr	%r0,%r0			# set cpuid to zero
175	lhi	%r1,2			# mode 2 = esame (dump)
176	sigp	%r1,%r0,0x12		# switch to esame mode
177	bras	%r13,0f
178	.fill	16,4,0x0
1790:	lmh	%r0,%r15,0(%r13)	# clear high-order half of gprs
180	sam31				# switch to 31 bit addressing mode
181	lh	%r1,__LC_SUBCHANNEL_ID	# test if subchannel number
182	bct	%r1,.Lnoload		#  is valid
183	l	%r1,__LC_SUBCHANNEL_ID	# load ipl subchannel number
184	la	%r2,IPL_BS		# load start address
185	bas	%r14,.Lloader		# load rest of ipl image
186	l	%r12,.Lparm		# pointer to parameter area
187	st	%r1,IPL_DEVICE+ARCH_OFFSET-PARMAREA(%r12) # save ipl device number
188
189#
190# load parameter file from ipl device
191#
192.Lagain1:
193	l	%r2,.Linitrd		# ramdisk loc. is temp
194	bas	%r14,.Lloader		# load parameter file
195	ltr	%r2,%r2 		# got anything ?
196	bz	.Lnopf
197	l	%r3,MAX_COMMAND_LINE_SIZE+ARCH_OFFSET-PARMAREA(%r12)
198	ahi	%r3,-1
199	clr	%r2,%r3
200	bl	.Lnotrunc
201	lr	%r2,%r3
202.Lnotrunc:
203	l	%r4,.Linitrd
204	clc	0(3,%r4),.L_hdr		# if it is HDRx
205	bz	.Lagain1		# skip dataset header
206	clc	0(3,%r4),.L_eof		# if it is EOFx
207	bz	.Lagain1		# skip dateset trailer
208
209	lr	%r5,%r2
210	la	%r6,COMMAND_LINE-PARMAREA(%r12)
211	lr	%r7,%r2
212	ahi	%r7,1
213	mvcl	%r6,%r4
214.Lnopf:
215
216#
217# load ramdisk from ipl device
218#
219.Lagain2:
220	l	%r2,.Linitrd		# addr of ramdisk
221	st	%r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
222	bas	%r14,.Lloader		# load ramdisk
223	st	%r2,INITRD_SIZE+ARCH_OFFSET-PARMAREA(%r12) # store size of rd
224	ltr	%r2,%r2
225	bnz	.Lrdcont
226	st	%r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # no ramdisk found
227.Lrdcont:
228	l	%r2,.Linitrd
229
230	clc	0(3,%r2),.L_hdr		# skip HDRx and EOFx
231	bz	.Lagain2
232	clc	0(3,%r2),.L_eof
233	bz	.Lagain2
234
235#
236# reset files in VM reader
237#
238	stidp	.Lcpuid			# store cpuid
239	tm	.Lcpuid,0xff		# running VM ?
240	bno	.Lnoreset
241	la	%r2,.Lreset
242	lhi	%r3,26
243	diag	%r2,%r3,8
244	la	%r5,.Lirb
245	stsch	0(%r5)			# check if irq is pending
246	tm	30(%r5),0x0f		# by verifying if any of the
247	bnz	.Lwaitforirq		# activity or status control
248	tm	31(%r5),0xff		# bits is set in the schib
249	bz	.Lnoreset
250.Lwaitforirq:
251	bas	%r14,.Lirqwait		# wait for IO interrupt
252	c	%r1,__LC_SUBCHANNEL_ID	# compare subchannel number
253	bne	.Lwaitforirq
254	la	%r5,.Lirb
255	tsch	0(%r5)
256.Lnoreset:
257	b	.Lnoload
258
259#
260# everything loaded, go for it
261#
262.Lnoload:
263	l	%r1,.Lstartup
264	br	%r1
265
266.Linitrd:.long _end			# default address of initrd
267.Lparm:	.long  PARMAREA
268.Lstartup: .long startup
269.Lreset:.byte	0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
270	.byte	0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
271	.byte	0xc8,0xd6,0xd3,0xc4	# "change rdr all keep nohold"
272.L_eof: .long	0xc5d6c600	 /* C'EOF' */
273.L_hdr: .long	0xc8c4d900	 /* C'HDR' */
274	.align	8
275.Lcpuid:.fill	8,1,0
276
277#
278# normal startup-code, running in absolute addressing mode
279# this is called either by the ipl loader or directly by PSW restart
280# or linload or SALIPL
281#
282	.org	STARTUP_NORMAL_OFFSET
283SYM_CODE_START(startup)
284	j	startup_normal
285	.org	EP_OFFSET
286#
287# This is a list of s390 kernel entry points. At address 0x1000f the number of
288# valid entry points is stored.
289#
290# IMPORTANT: Do not change this table, it is s390 kernel ABI!
291#
292	.ascii	EP_STRING
293	.byte	0x00,0x01
294#
295# kdump startup-code, running in 64 bit absolute addressing mode
296#
297	.org	STARTUP_KDUMP_OFFSET
298	j	startup_kdump
299SYM_CODE_END(startup)
300SYM_CODE_START_LOCAL(startup_normal)
301	mvi	__LC_AR_MODE_ID,1	# set esame flag
302	slr	%r0,%r0 		# set cpuid to zero
303	lhi	%r1,2			# mode 2 = esame (dump)
304	sigp	%r1,%r0,0x12		# switch to esame mode
305	bras	%r13,0f
306	.fill	16,4,0x0
3070:	lmh	%r0,%r15,0(%r13)	# clear high-order half of gprs
308	sam64				# switch to 64 bit addressing mode
309	basr	%r13,0			# get base
310.LPG0:
311	mvc	__LC_EXT_NEW_PSW(16),.Lext_new_psw-.LPG0(%r13)
312	mvc	__LC_PGM_NEW_PSW(16),.Lpgm_new_psw-.LPG0(%r13)
313	mvc	__LC_IO_NEW_PSW(16),.Lio_new_psw-.LPG0(%r13)
314	xc	0x200(256),0x200	# partially clear lowcore
315	xc	0x300(256),0x300
316	xc	0xe00(256),0xe00
317	xc	0xf00(256),0xf00
318	lctlg	%c0,%c15,.Lctl-.LPG0(%r13)	# load control registers
319	stcke	__LC_BOOT_CLOCK
320	mvc	__LC_LAST_UPDATE_CLOCK(8),__LC_BOOT_CLOCK+1
321	spt	6f-.LPG0(%r13)
322	mvc	__LC_LAST_UPDATE_TIMER(8),6f-.LPG0(%r13)
323	larl	%r15,_stack_end-STACK_FRAME_OVERHEAD
324	brasl	%r14,sclp_early_setup_buffer
325	brasl	%r14,verify_facilities
326	brasl	%r14,startup_kernel
327SYM_CODE_END(startup_normal)
328
329	.align	8
3306:	.long	0x7fffffff,0xffffffff
331.Lext_new_psw:
332	.quad	0x0002000180000000,0x1b0	# disabled wait
333.Lpgm_new_psw:
334	.quad	0x0000000180000000,startup_pgm_check_handler
335.Lio_new_psw:
336	.quad	0x0002000180000000,0x1f0	# disabled wait
337.Lctl:	.quad	0x04040000		# cr0: AFP registers & secondary space
338	.quad	0			# cr1: primary space segment table
339	.quad	0			# cr2: dispatchable unit control table
340	.quad	0			# cr3: instruction authorization
341	.quad	0xffff			# cr4: instruction authorization
342	.quad	0			# cr5: primary-aste origin
343	.quad	0			# cr6:	I/O interrupts
344	.quad	0			# cr7:	secondary space segment table
345	.quad	0x0000000000008000	# cr8:	access registers translation
346	.quad	0			# cr9:	tracing off
347	.quad	0			# cr10: tracing off
348	.quad	0			# cr11: tracing off
349	.quad	0			# cr12: tracing off
350	.quad	0			# cr13: home space segment table
351	.quad	0xc0000000		# cr14: machine check handling off
352	.quad	0			# cr15: linkage stack operations
353
354#include "head_kdump.S"
355
356#
357# This program check is active immediately after kernel start
358# and until early_pgm_check_handler is set in kernel/early.c
359# It simply saves general/control registers and psw in
360# the save area and does disabled wait with a faulty address.
361#
362SYM_CODE_START_LOCAL(startup_pgm_check_handler)
363	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
364	la	%r8,4095
365	stctg	%c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r8)
366	stmg	%r0,%r7,__LC_GPREGS_SAVE_AREA-4095(%r8)
367	mvc	__LC_GPREGS_SAVE_AREA-4095+64(64,%r8),__LC_SAVE_AREA_SYNC
368	mvc	__LC_PSW_SAVE_AREA-4095(16,%r8),__LC_PGM_OLD_PSW
369	mvc	__LC_RETURN_PSW(16),__LC_PGM_OLD_PSW
370	ni	__LC_RETURN_PSW,0xfc	# remove IO and EX bits
371	ni	__LC_RETURN_PSW+1,0xfb	# remove MCHK bit
372	oi	__LC_RETURN_PSW+1,0x2	# set wait state bit
373	larl	%r9,.Lold_psw_disabled_wait
374	stg	%r9,__LC_PGM_NEW_PSW+8
375	larl	%r15,_dump_info_stack_end-STACK_FRAME_OVERHEAD
376	brasl	%r14,print_pgm_check_info
377.Lold_psw_disabled_wait:
378	la	%r8,4095
379	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r8)
380	lpswe	__LC_RETURN_PSW		# disabled wait
381SYM_CODE_END(startup_pgm_check_handler)
382
383#
384# params at 10400 (setup.h)
385# Must be keept in sync with struct parmarea in setup.h
386#
387	.org	PARMAREA
388SYM_DATA_START(parmarea)
389	.quad	0			# IPL_DEVICE
390	.quad	0			# INITRD_START
391	.quad	0			# INITRD_SIZE
392	.quad	0			# OLDMEM_BASE
393	.quad	0			# OLDMEM_SIZE
394	.quad	kernel_version		# points to kernel version string
395	.quad	COMMAND_LINE_SIZE
396
397	.org	COMMAND_LINE
398	.byte	"root=/dev/ram0 ro"
399	.byte	0
400	.org	PARMAREA+__PARMAREA_SIZE
401SYM_DATA_END(parmarea)
402