xref: /openbmc/linux/arch/s390/boot/head.S (revision 2612e3bbc0386368a850140a6c9b990cd496a5ec)
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 #include "boot.h"
31 
32 #define EP_OFFSET	0x10008
33 #define EP_STRING	"S390EP"
34 #define IPL_BS		0x730
35 
36 __HEAD
37 ipl_start:
38 	mvi	__LC_AR_MODE_ID,1	# set esame flag
39 	slr	%r0,%r0			# set cpuid to zero
40 	lhi	%r1,2			# mode 2 = esame (dump)
41 	sigp	%r1,%r0,0x12		# switch to esame mode
42 	sam64				# switch to 64 bit addressing mode
43 	lgh	%r1,__LC_SUBCHANNEL_ID	# test if subchannel number
44 	brctg	%r1,.Lnoload		#  is valid
45 	llgf	%r1,__LC_SUBCHANNEL_ID	# load ipl subchannel number
46 	lghi	%r2,IPL_BS		# load start address
47 	bras	%r14,.Lloader		# load rest of ipl image
48 	larl	%r12,parmarea		# pointer to parameter area
49 	stg	%r1,IPL_DEVICE-PARMAREA(%r12) # save ipl device number
50 #
51 # load parameter file from ipl device
52 #
53 .Lagain1:
54 	larl	%r2,_end		# ramdisk loc. is temp
55 	bras	%r14,.Lloader		# load parameter file
56 	ltgr	%r2,%r2			# got anything ?
57 	jz	.Lnopf
58 	lg	%r3,MAX_COMMAND_LINE_SIZE-PARMAREA(%r12)
59 	aghi	%r3,-1
60 	clgr	%r2,%r3
61 	jl	.Lnotrunc
62 	lgr	%r2,%r3
63 .Lnotrunc:
64 	larl	%r4,_end
65 	larl	%r13,.L_hdr
66 	clc	0(3,%r4),0(%r13)	# if it is HDRx
67 	jz	.Lagain1		# skip dataset header
68 	larl	%r13,.L_eof
69 	clc	0(3,%r4),0(%r13)	# if it is EOFx
70 	jz	.Lagain1		# skip data set trailer
71 	lgr	%r5,%r2
72 	la	%r6,COMMAND_LINE-PARMAREA(%r12)
73 	lgr	%r7,%r2
74 	aghi	%r7,1
75 	mvcl	%r6,%r4
76 .Lnopf:
77 #
78 # load ramdisk from ipl device
79 #
80 .Lagain2:
81 	larl	%r2,_end		# addr of ramdisk
82 	stg	%r2,INITRD_START-PARMAREA(%r12)
83 	bras	%r14,.Lloader		# load ramdisk
84 	stg	%r2,INITRD_SIZE-PARMAREA(%r12) # store size of rd
85 	ltgr	%r2,%r2
86 	jnz	.Lrdcont
87 	stg	%r2,INITRD_START-PARMAREA(%r12) # no ramdisk found
88 .Lrdcont:
89 	larl	%r2,_end
90 	larl	%r13,.L_hdr		# skip HDRx and EOFx
91 	clc	0(3,%r2),0(%r13)
92 	jz	.Lagain2
93 	larl	%r13,.L_eof
94 	clc	0(3,%r2),0(%r13)
95 	jz	.Lagain2
96 #
97 # reset files in VM reader
98 #
99 	larl	%r13,.Lcpuid
100 	stidp	0(%r13)			# store cpuid
101 	tm	0(%r13),0xff		# running VM ?
102 	jno	.Lnoreset
103 	larl	%r2,.Lreset
104 	lghi	%r3,26
105 	diag	%r2,%r3,8
106 	larl	%r5,.Lirb
107 	stsch	0(%r5)			# check if irq is pending
108 	tm	30(%r5),0x0f		# by verifying if any of the
109 	jnz	.Lwaitforirq		# activity or status control
110 	tm	31(%r5),0xff		# bits is set in the schib
111 	jz	.Lnoreset
112 .Lwaitforirq:
113 	bras	%r14,.Lirqwait		# wait for IO interrupt
114 	c	%r1,__LC_SUBCHANNEL_ID	# compare subchannel number
115 	jne	.Lwaitforirq
116 	larl	%r5,.Lirb
117 	tsch	0(%r5)
118 .Lnoreset:
119 	j	.Lnoload
120 #
121 # everything loaded, go for it
122 #
123 .Lnoload:
124 	jg	startup
125 #
126 # subroutine to wait for end I/O
127 #
128 .Lirqwait:
129 	larl	%r13,.Lnewpswmask	# set up IO interrupt psw
130 	mvc	__LC_IO_NEW_PSW(8),0(%r13)
131 	stg	%r14,__LC_IO_NEW_PSW+8
132 	larl	%r13,.Lwaitpsw
133 	lpswe	0(%r13)
134 .Lioint:
135 #
136 # subroutine for loading cards from the reader
137 #
138 .Lloader:
139 	lgr	%r4,%r14
140 	larl	%r3,.Lorb		# r2 = address of orb into r2
141 	larl	%r5,.Lirb		# r4 = address of irb
142 	larl	%r6,.Lccws
143 	lghi	%r7,20
144 .Linit:
145 	st	%r2,4(%r6)		# initialize CCW data addresses
146 	la	%r2,0x50(%r2)
147 	la	%r6,8(%r6)
148 	brctg	%r7,.Linit
149 	larl	%r13,.Lcr6
150 	lctlg	%c6,%c6,0(%r13)
151 	xgr	%r2,%r2
152 .Lldlp:
153 	ssch	0(%r3)			# load chunk of 1600 bytes
154 	jnz	.Llderr
155 .Lwait4irq:
156 	bras	%r14,.Lirqwait
157 	c	%r1,__LC_SUBCHANNEL_ID	# compare subchannel number
158 	jne	.Lwait4irq
159 	tsch	0(%r5)
160 	xgr	%r0,%r0
161 	ic	%r0,8(%r5)		# get device status
162 	cghi	%r0,8			# channel end ?
163 	je	.Lcont
164 	cghi	%r0,12			# channel end + device end ?
165 	je	.Lcont
166 	llgf	%r0,4(%r5)
167 	sgf	%r0,8(%r3)		# r0/8 = number of ccws executed
168 	mghi	%r0,10			# *10 = number of bytes in ccws
169 	llgh	%r3,10(%r5)		# get residual count
170 	sgr	%r0,%r3			# #ccws*80-residual=#bytes read
171 	agr	%r2,%r0
172 	br	%r4			# r2 contains the total size
173 .Lcont:
174 	aghi	%r2,0x640		# add 0x640 to total size
175 	larl	%r6,.Lccws
176 	lghi	%r7,20
177 .Lincr:
178 	l	%r0,4(%r6)		# update CCW data addresses
179 	aghi	%r0,0x640
180 	st	%r0,4(%r6)
181 	aghi	%r6,8
182 	brctg	%r7,.Lincr
183 	j	.Lldlp
184 .Llderr:
185 	larl	%r13,.Lcrash
186 	lpsw	0(%r13)
187 
188 	.balign	8
189 .Lwaitpsw:
190 	.quad	0x0202000180000000,.Lioint
191 .Lnewpswmask:
192 	.quad	0x0000000180000000
193 	.balign	8
194 .Lorb:	.long	0x00000000,0x0080ff00,.Lccws
195 .Lirb:	.long	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
196 	.balign	8
197 .Lcr6:	.quad	0x00000000ff000000
198 	.balign	8
199 .Lcrash:.long	0x000a0000,0x00000000
200 	.balign	8
201 .Lccws: .rept	19
202 	.long	0x02600050,0x00000000
203 	.endr
204 	.long	0x02200050,0x00000000
205 .Lreset:.byte	0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
206 	.byte	0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
207 	.byte	0xc8,0xd6,0xd3,0xc4	# "change rdr all keep nohold"
208 .L_eof: .long	0xc5d6c600	 /* C'EOF' */
209 .L_hdr: .long	0xc8c4d900	 /* C'HDR' */
210 	.balign	8
211 .Lcpuid:.fill	8,1,0
212 
213 #
214 # normal startup-code, running in absolute addressing mode
215 # this is called either by the ipl loader or directly by PSW restart
216 # or linload or SALIPL
217 #
218 	.org	STARTUP_NORMAL_OFFSET - IPL_START
219 SYM_CODE_START(startup)
220 	j	startup_normal
221 	.org	EP_OFFSET - IPL_START
222 #
223 # This is a list of s390 kernel entry points. At address 0x1000f the number of
224 # valid entry points is stored.
225 #
226 # IMPORTANT: Do not change this table, it is s390 kernel ABI!
227 #
228 	.ascii	EP_STRING
229 	.byte	0x00,0x01
230 #
231 # kdump startup-code, running in 64 bit absolute addressing mode
232 #
233 	.org	STARTUP_KDUMP_OFFSET - IPL_START
234 	j	startup_kdump
235 SYM_CODE_END(startup)
236 SYM_CODE_START_LOCAL(startup_normal)
237 	mvi	__LC_AR_MODE_ID,1	# set esame flag
238 	slr	%r0,%r0 		# set cpuid to zero
239 	lhi	%r1,2			# mode 2 = esame (dump)
240 	sigp	%r1,%r0,0x12		# switch to esame mode
241 	bras	%r13,0f
242 	.fill	16,4,0x0
243 0:	lmh	%r0,%r15,0(%r13)	# clear high-order half of gprs
244 	sam64				# switch to 64 bit addressing mode
245 	larl	%r13,.Lext_new_psw
246 	mvc	__LC_EXT_NEW_PSW(16),0(%r13)
247 	larl	%r13,.Lpgm_new_psw
248 	mvc	__LC_PGM_NEW_PSW(16),0(%r13)
249 	larl	%r13,.Lio_new_psw
250 	mvc	__LC_IO_NEW_PSW(16),0(%r13)
251 	xc	0x200(256),0x200	# partially clear lowcore
252 	xc	0x300(256),0x300
253 	xc	0xe00(256),0xe00
254 	xc	0xf00(256),0xf00
255 	larl	%r13,.Lctl
256 	lctlg	%c0,%c15,0(%r13)	# load control registers
257 	stcke	__LC_BOOT_CLOCK
258 	mvc	__LC_LAST_UPDATE_CLOCK(8),__LC_BOOT_CLOCK+1
259 	larl	%r13,6f
260 	spt	0(%r13)
261 	mvc	__LC_LAST_UPDATE_TIMER(8),0(%r13)
262 	larl	%r15,_stack_end-STACK_FRAME_OVERHEAD
263 	brasl	%r14,sclp_early_setup_buffer
264 	brasl	%r14,verify_facilities
265 	brasl	%r14,startup_kernel
266 SYM_CODE_END(startup_normal)
267 
268 	.balign	8
269 6:	.long	0x7fffffff,0xffffffff
270 .Lext_new_psw:
271 	.quad	0x0002000180000000,0x1b0	# disabled wait
272 .Lpgm_new_psw:
273 	.quad	0x0000000180000000,startup_pgm_check_handler
274 .Lio_new_psw:
275 	.quad	0x0002000180000000,0x1f0	# disabled wait
276 .Lctl:	.quad	0x04040000		# cr0: AFP registers & secondary space
277 	.quad	0			# cr1: primary space segment table
278 	.quad	0			# cr2: dispatchable unit control table
279 	.quad	0			# cr3: instruction authorization
280 	.quad	0xffff			# cr4: instruction authorization
281 	.quad	0			# cr5: primary-aste origin
282 	.quad	0			# cr6:	I/O interrupts
283 	.quad	0			# cr7:	secondary space segment table
284 	.quad	0x0000000000008000	# cr8:	access registers translation
285 	.quad	0			# cr9:	tracing off
286 	.quad	0			# cr10: tracing off
287 	.quad	0			# cr11: tracing off
288 	.quad	0			# cr12: tracing off
289 	.quad	0			# cr13: home space segment table
290 	.quad	0xc0000000		# cr14: machine check handling off
291 	.quad	0			# cr15: linkage stack operations
292 
293 #include "head_kdump.S"
294 
295 #
296 # This program check is active immediately after kernel start
297 # and until early_pgm_check_handler is set in kernel/early.c
298 # It simply saves general/control registers and psw in
299 # the save area and does disabled wait with a faulty address.
300 #
301 SYM_CODE_START_LOCAL(startup_pgm_check_handler)
302 	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC
303 	la	%r8,4095
304 	stctg	%c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r8)
305 	stmg	%r0,%r7,__LC_GPREGS_SAVE_AREA-4095(%r8)
306 	mvc	__LC_GPREGS_SAVE_AREA-4095+64(64,%r8),__LC_SAVE_AREA_SYNC
307 	mvc	__LC_PSW_SAVE_AREA-4095(16,%r8),__LC_PGM_OLD_PSW
308 	mvc	__LC_RETURN_PSW(16),__LC_PGM_OLD_PSW
309 	ni	__LC_RETURN_PSW,0xfc	# remove IO and EX bits
310 	ni	__LC_RETURN_PSW+1,0xfb	# remove MCHK bit
311 	oi	__LC_RETURN_PSW+1,0x2	# set wait state bit
312 	larl	%r9,.Lold_psw_disabled_wait
313 	stg	%r9,__LC_PGM_NEW_PSW+8
314 	larl	%r15,_dump_info_stack_end-STACK_FRAME_OVERHEAD
315 	brasl	%r14,print_pgm_check_info
316 .Lold_psw_disabled_wait:
317 	la	%r8,4095
318 	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r8)
319 	lpswe	__LC_RETURN_PSW		# disabled wait
320 SYM_CODE_END(startup_pgm_check_handler)
321