xref: /linux/arch/s390/boot/head.S (revision 3f0a50f345f78183f6e9b39c2f45ca5dcaa511ca)
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__HEAD
37
38#define IPL_BS	0x730
39	.org	0
40	.long	0x00080000,0x80000000+iplstart	# The first 24 bytes are loaded
41	.long	0x02000018,0x60000050		# by ipl to addresses 0-23.
42	.long	0x02000068,0x60000050		# (a PSW and two CCWs).
43	.fill	80-24,1,0x40			# bytes 24-79 are discarded !!
44	.long	0x020000f0,0x60000050		# The next 160 byte are loaded
45	.long	0x02000140,0x60000050		# to addresses 0x18-0xb7
46	.long	0x02000190,0x60000050		# They form the continuation
47	.long	0x020001e0,0x60000050		# of the CCW program started
48	.long	0x02000230,0x60000050		# by ipl and load the range
49	.long	0x02000280,0x60000050		# 0x0f0-0x730 from the image
50	.long	0x020002d0,0x60000050		# to the range 0x0f0-0x730
51	.long	0x02000320,0x60000050		# in memory. At the end of
52	.long	0x02000370,0x60000050		# the channel program the PSW
53	.long	0x020003c0,0x60000050		# at location 0 is loaded.
54	.long	0x02000410,0x60000050		# Initial processing starts
55	.long	0x02000460,0x60000050		# at 0x200 = iplstart.
56	.long	0x020004b0,0x60000050
57	.long	0x02000500,0x60000050
58	.long	0x02000550,0x60000050
59	.long	0x020005a0,0x60000050
60	.long	0x020005f0,0x60000050
61	.long	0x02000640,0x60000050
62	.long	0x02000690,0x60000050
63	.long	0x020006e0,0x20000050
64
65	.org	__LC_RST_NEW_PSW		# 0x1a0
66	.quad	0,iplstart
67	.org	__LC_EXT_NEW_PSW		# 0x1b0
68	.quad	0x0002000180000000,0x1b0	# disabled wait
69	.org	__LC_PGM_NEW_PSW		# 0x1d0
70	.quad	0x0000000180000000,startup_pgm_check_handler
71	.org	__LC_IO_NEW_PSW			# 0x1f0
72	.quad	0x0002000180000000,0x1f0	# disabled wait
73
74	.org	0x200
75
76#
77# subroutine to wait for end I/O
78#
79.Lirqwait:
80	mvc	__LC_IO_NEW_PSW(16),.Lnewpsw	# set up IO interrupt psw
81	lpsw	.Lwaitpsw
82.Lioint:
83	br	%r14
84	.align	8
85.Lnewpsw:
86	.quad	0x0000000080000000,.Lioint
87.Lwaitpsw:
88	.long	0x020a0000,0x80000000+.Lioint
89
90#
91# subroutine for loading cards from the reader
92#
93.Lloader:
94	la	%r4,0(%r14)
95	la	%r3,.Lorb		# r2 = address of orb into r2
96	la	%r5,.Lirb		# r4 = address of irb
97	la	%r6,.Lccws
98	la	%r7,20
99.Linit:
100	st	%r2,4(%r6)		# initialize CCW data addresses
101	la	%r2,0x50(%r2)
102	la	%r6,8(%r6)
103	bct	7,.Linit
104
105	lctl	%c6,%c6,.Lcr6		# set IO subclass mask
106	slr	%r2,%r2
107.Lldlp:
108	ssch	0(%r3)			# load chunk of 1600 bytes
109	bnz	.Llderr
110.Lwait4irq:
111	bas	%r14,.Lirqwait
112	c	%r1,__LC_SUBCHANNEL_ID	# compare subchannel number
113	bne	.Lwait4irq
114	tsch	0(%r5)
115
116	slr	%r0,%r0
117	ic	%r0,8(%r5)		# get device status
118	chi	%r0,8			# channel end ?
119	be	.Lcont
120	chi	%r0,12			# channel end + device end ?
121	be	.Lcont
122
123	l	%r0,4(%r5)
124	s	%r0,8(%r3)		# r0/8 = number of ccws executed
125	mhi	%r0,10			# *10 = number of bytes in ccws
126	lh	%r3,10(%r5)		# get residual count
127	sr	%r0,%r3 		# #ccws*80-residual=#bytes read
128	ar	%r2,%r0
129
130	br	%r4			# r2 contains the total size
131
132.Lcont:
133	ahi	%r2,0x640		# add 0x640 to total size
134	la	%r6,.Lccws
135	la	%r7,20
136.Lincr:
137	l	%r0,4(%r6)		# update CCW data addresses
138	ahi	%r0,0x640
139	st	%r0,4(%r6)
140	ahi	%r6,8
141	bct	7,.Lincr
142
143	b	.Lldlp
144.Llderr:
145	lpsw	.Lcrash
146
147	.align	8
148.Lorb:	.long	0x00000000,0x0080ff00,.Lccws
149.Lirb:	.long	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
150.Lcr6:	.long	0xff000000
151.Lloadp:.long	0,0
152	.align	8
153.Lcrash:.long	0x000a0000,0x00000000
154
155	.align	8
156.Lccws: .rept	19
157	.long	0x02600050,0x00000000
158	.endr
159	.long	0x02200050,0x00000000
160
161iplstart:
162	mvi	__LC_AR_MODE_ID,1	# set esame flag
163	slr	%r0,%r0			# set cpuid to zero
164	lhi	%r1,2			# mode 2 = esame (dump)
165	sigp	%r1,%r0,0x12		# switch to esame mode
166	bras	%r13,0f
167	.fill	16,4,0x0
1680:	lmh	%r0,%r15,0(%r13)	# clear high-order half of gprs
169	sam31				# switch to 31 bit addressing mode
170	lh	%r1,__LC_SUBCHANNEL_ID	# test if subchannel number
171	bct	%r1,.Lnoload		#  is valid
172	l	%r1,__LC_SUBCHANNEL_ID	# load ipl subchannel number
173	la	%r2,IPL_BS		# load start address
174	bas	%r14,.Lloader		# load rest of ipl image
175	l	%r12,.Lparm		# pointer to parameter area
176	st	%r1,IPL_DEVICE+ARCH_OFFSET-PARMAREA(%r12) # save ipl device number
177
178#
179# load parameter file from ipl device
180#
181.Lagain1:
182	l	%r2,.Linitrd		# ramdisk loc. is temp
183	bas	%r14,.Lloader		# load parameter file
184	ltr	%r2,%r2 		# got anything ?
185	bz	.Lnopf
186	l	%r3,MAX_COMMAND_LINE_SIZE+ARCH_OFFSET-PARMAREA(%r12)
187	ahi	%r3,-1
188	clr	%r2,%r3
189	bl	.Lnotrunc
190	lr	%r2,%r3
191.Lnotrunc:
192	l	%r4,.Linitrd
193	clc	0(3,%r4),.L_hdr		# if it is HDRx
194	bz	.Lagain1		# skip dataset header
195	clc	0(3,%r4),.L_eof		# if it is EOFx
196	bz	.Lagain1		# skip dateset trailer
197
198	lr	%r5,%r2
199	la	%r6,COMMAND_LINE-PARMAREA(%r12)
200	lr	%r7,%r2
201	ahi	%r7,1
202	mvcl	%r6,%r4
203.Lnopf:
204
205#
206# load ramdisk from ipl device
207#
208.Lagain2:
209	l	%r2,.Linitrd		# addr of ramdisk
210	st	%r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
211	bas	%r14,.Lloader		# load ramdisk
212	st	%r2,INITRD_SIZE+ARCH_OFFSET-PARMAREA(%r12) # store size of rd
213	ltr	%r2,%r2
214	bnz	.Lrdcont
215	st	%r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # no ramdisk found
216.Lrdcont:
217	l	%r2,.Linitrd
218
219	clc	0(3,%r2),.L_hdr		# skip HDRx and EOFx
220	bz	.Lagain2
221	clc	0(3,%r2),.L_eof
222	bz	.Lagain2
223
224#
225# reset files in VM reader
226#
227	stidp	.Lcpuid			# store cpuid
228	tm	.Lcpuid,0xff		# running VM ?
229	bno	.Lnoreset
230	la	%r2,.Lreset
231	lhi	%r3,26
232	diag	%r2,%r3,8
233	la	%r5,.Lirb
234	stsch	0(%r5)			# check if irq is pending
235	tm	30(%r5),0x0f		# by verifying if any of the
236	bnz	.Lwaitforirq		# activity or status control
237	tm	31(%r5),0xff		# bits is set in the schib
238	bz	.Lnoreset
239.Lwaitforirq:
240	bas	%r14,.Lirqwait		# wait for IO interrupt
241	c	%r1,__LC_SUBCHANNEL_ID	# compare subchannel number
242	bne	.Lwaitforirq
243	la	%r5,.Lirb
244	tsch	0(%r5)
245.Lnoreset:
246	b	.Lnoload
247
248#
249# everything loaded, go for it
250#
251.Lnoload:
252	l	%r1,.Lstartup
253	br	%r1
254
255.Linitrd:.long _end			# default address of initrd
256.Lparm:	.long  PARMAREA
257.Lstartup: .long startup
258.Lreset:.byte	0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
259	.byte	0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
260	.byte	0xc8,0xd6,0xd3,0xc4	# "change rdr all keep nohold"
261.L_eof: .long	0xc5d6c600	 /* C'EOF' */
262.L_hdr: .long	0xc8c4d900	 /* C'HDR' */
263	.align	8
264.Lcpuid:.fill	8,1,0
265
266#
267# normal startup-code, running in absolute addressing mode
268# this is called either by the ipl loader or directly by PSW restart
269# or linload or SALIPL
270#
271	.org	STARTUP_NORMAL_OFFSET
272SYM_CODE_START(startup)
273	j	startup_normal
274	.org	EP_OFFSET
275#
276# This is a list of s390 kernel entry points. At address 0x1000f the number of
277# valid entry points is stored.
278#
279# IMPORTANT: Do not change this table, it is s390 kernel ABI!
280#
281	.ascii	EP_STRING
282	.byte	0x00,0x01
283#
284# kdump startup-code, running in 64 bit absolute addressing mode
285#
286	.org	STARTUP_KDUMP_OFFSET
287	j	startup_kdump
288SYM_CODE_END(startup)
289SYM_CODE_START_LOCAL(startup_normal)
290	mvi	__LC_AR_MODE_ID,1	# set esame flag
291	slr	%r0,%r0 		# set cpuid to zero
292	lhi	%r1,2			# mode 2 = esame (dump)
293	sigp	%r1,%r0,0x12		# switch to esame mode
294	bras	%r13,0f
295	.fill	16,4,0x0
2960:	lmh	%r0,%r15,0(%r13)	# clear high-order half of gprs
297	sam64				# switch to 64 bit addressing mode
298	basr	%r13,0			# get base
299.LPG0:
300	mvc	__LC_EXT_NEW_PSW(16),.Lext_new_psw-.LPG0(%r13)
301	mvc	__LC_PGM_NEW_PSW(16),.Lpgm_new_psw-.LPG0(%r13)
302	mvc	__LC_IO_NEW_PSW(16),.Lio_new_psw-.LPG0(%r13)
303	xc	0x200(256),0x200	# partially clear lowcore
304	xc	0x300(256),0x300
305	xc	0xe00(256),0xe00
306	xc	0xf00(256),0xf00
307	lctlg	%c0,%c15,.Lctl-.LPG0(%r13)	# load control registers
308	stcke	__LC_BOOT_CLOCK
309	mvc	__LC_LAST_UPDATE_CLOCK(8),__LC_BOOT_CLOCK+1
310	spt	6f-.LPG0(%r13)
311	mvc	__LC_LAST_UPDATE_TIMER(8),6f-.LPG0(%r13)
312	larl	%r15,_stack_end-STACK_FRAME_OVERHEAD
313	brasl	%r14,sclp_early_setup_buffer
314	brasl	%r14,verify_facilities
315	brasl	%r14,startup_kernel
316SYM_CODE_END(startup_normal)
317
318	.align	8
3196:	.long	0x7fffffff,0xffffffff
320.Lext_new_psw:
321	.quad	0x0002000180000000,0x1b0	# disabled wait
322.Lpgm_new_psw:
323	.quad	0x0000000180000000,startup_pgm_check_handler
324.Lio_new_psw:
325	.quad	0x0002000180000000,0x1f0	# disabled wait
326.Lctl:	.quad	0x04040000		# cr0: AFP registers & secondary space
327	.quad	0			# cr1: primary space segment table
328	.quad	0			# cr2: dispatchable unit control table
329	.quad	0			# cr3: instruction authorization
330	.quad	0xffff			# cr4: instruction authorization
331	.quad	0			# cr5: primary-aste origin
332	.quad	0			# cr6:	I/O interrupts
333	.quad	0			# cr7:	secondary space segment table
334	.quad	0x0000000000008000	# cr8:	access registers translation
335	.quad	0			# cr9:	tracing off
336	.quad	0			# cr10: tracing off
337	.quad	0			# cr11: tracing off
338	.quad	0			# cr12: tracing off
339	.quad	0			# cr13: home space segment table
340	.quad	0xc0000000		# cr14: machine check handling off
341	.quad	0			# cr15: linkage stack operations
342
343#include "head_kdump.S"
344
345#
346# This program check is active immediately after kernel start
347# and until early_pgm_check_handler is set in kernel/early.c
348# It simply saves general/control registers and psw in
349# the save area and does disabled wait with a faulty address.
350#
351SYM_CODE_START_LOCAL(startup_pgm_check_handler)
352	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
353	la	%r8,4095
354	stctg	%c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r8)
355	stmg	%r0,%r7,__LC_GPREGS_SAVE_AREA-4095(%r8)
356	mvc	__LC_GPREGS_SAVE_AREA-4095+64(64,%r8),__LC_SAVE_AREA_SYNC
357	mvc	__LC_PSW_SAVE_AREA-4095(16,%r8),__LC_PGM_OLD_PSW
358	mvc	__LC_RETURN_PSW(16),__LC_PGM_OLD_PSW
359	ni	__LC_RETURN_PSW,0xfc	# remove IO and EX bits
360	ni	__LC_RETURN_PSW+1,0xfb	# remove MCHK bit
361	oi	__LC_RETURN_PSW+1,0x2	# set wait state bit
362	larl	%r9,.Lold_psw_disabled_wait
363	stg	%r9,__LC_PGM_NEW_PSW+8
364	larl	%r15,_dump_info_stack_end-STACK_FRAME_OVERHEAD
365	brasl	%r14,print_pgm_check_info
366.Lold_psw_disabled_wait:
367	la	%r8,4095
368	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r8)
369	lpswe	__LC_RETURN_PSW		# disabled wait
370SYM_CODE_END(startup_pgm_check_handler)
371
372#
373# params at 10400 (setup.h)
374# Must be keept in sync with struct parmarea in setup.h
375#
376	.org	PARMAREA
377SYM_DATA_START(parmarea)
378	.quad	0			# IPL_DEVICE
379	.quad	0			# INITRD_START
380	.quad	0			# INITRD_SIZE
381	.quad	0			# OLDMEM_BASE
382	.quad	0			# OLDMEM_SIZE
383	.quad	kernel_version		# points to kernel version string
384	.quad	COMMAND_LINE_SIZE
385
386	.org	COMMAND_LINE
387	.byte	"root=/dev/ram0 ro"
388	.byte	0
389	.org	PARMAREA+__PARMAREA_SIZE
390SYM_DATA_END(parmarea)
391