if_cs_mainbus.c revision 1.4 1 1.4 tsutsui /* $NetBSD: if_cs_mainbus.c,v 1.4 2009/09/22 14:55:19 tsutsui Exp $ */
2 1.2 garbled
3 1.2 garbled /*
4 1.2 garbled * Copyright (c) 2002 The NetBSD Foundation, Inc.
5 1.2 garbled * All rights reserved.
6 1.2 garbled *
7 1.2 garbled * This code is derived from software contributed to The NetBSD Foundation
8 1.2 garbled * by Lennart Augustsson (lennart (at) augustsson.net) at Sandburst Corp.
9 1.2 garbled *
10 1.2 garbled * Redistribution and use in source and binary forms, with or without
11 1.2 garbled * modification, are permitted provided that the following conditions
12 1.2 garbled * are met:
13 1.2 garbled * 1. Redistributions of source code must retain the above copyright
14 1.2 garbled * notice, this list of conditions and the following disclaimer.
15 1.2 garbled * 2. Redistributions in binary form must reproduce the above copyright
16 1.2 garbled * notice, this list of conditions and the following disclaimer in the
17 1.2 garbled * documentation and/or other materials provided with the distribution.
18 1.2 garbled *
19 1.2 garbled * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 1.2 garbled * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 1.2 garbled * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 1.2 garbled * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 1.2 garbled * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 1.2 garbled * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 1.2 garbled * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 1.2 garbled * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 1.2 garbled * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 1.2 garbled * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 1.2 garbled * POSSIBILITY OF SUCH DAMAGE.
30 1.2 garbled */
31 1.2 garbled
32 1.2 garbled #include <sys/cdefs.h>
33 1.4 tsutsui __KERNEL_RCSID(0, "$NetBSD: if_cs_mainbus.c,v 1.4 2009/09/22 14:55:19 tsutsui Exp $");
34 1.2 garbled
35 1.2 garbled #include <sys/param.h>
36 1.2 garbled #include <sys/device.h>
37 1.2 garbled #include <sys/systm.h>
38 1.2 garbled #include <sys/socket.h>
39 1.2 garbled
40 1.2 garbled #include "rnd.h"
41 1.2 garbled #if NRND > 0
42 1.2 garbled #include <sys/rnd.h>
43 1.2 garbled #endif
44 1.2 garbled
45 1.2 garbled #include <net/if.h>
46 1.2 garbled #include <net/if_ether.h>
47 1.2 garbled #include <net/if_media.h>
48 1.2 garbled #ifdef INET
49 1.2 garbled #include <netinet/in.h>
50 1.2 garbled #include <netinet/if_inarp.h>
51 1.2 garbled #endif
52 1.2 garbled
53 1.2 garbled #include <machine/bus.h>
54 1.2 garbled #include <machine/pio.h>
55 1.2 garbled #include <machine/pmppc.h>
56 1.2 garbled #include <arch/evbppc/pmppc/dev/mainbus.h>
57 1.2 garbled
58 1.2 garbled #include <dev/ic/cs89x0reg.h>
59 1.2 garbled #include <dev/ic/cs89x0var.h>
60 1.2 garbled
61 1.2 garbled #include <sys/callout.h>
62 1.2 garbled
63 1.2 garbled #define ATSN_EEPROM_MAC_OFFSET 0x20
64 1.2 garbled
65 1.2 garbled
66 1.2 garbled static void cs_check_eeprom(struct cs_softc *sc);
67 1.2 garbled
68 1.2 garbled static int cs_mainbus_match(struct device *, struct cfdata *, void *);
69 1.2 garbled static void cs_mainbus_attach(struct device *, struct device *, void *);
70 1.2 garbled
71 1.4 tsutsui CFATTACH_DECL_NEW(cs_mainbus, sizeof(struct cs_softc),
72 1.2 garbled cs_mainbus_match, cs_mainbus_attach, NULL, NULL);
73 1.2 garbled
74 1.2 garbled int
75 1.4 tsutsui cs_mainbus_match(device_t parent, cfdata_t cf, void *aux)
76 1.2 garbled {
77 1.2 garbled struct mainbus_attach_args *maa = aux;
78 1.2 garbled
79 1.2 garbled return (strcmp(maa->mb_name, "cs") == 0);
80 1.2 garbled }
81 1.2 garbled
82 1.2 garbled #if 0
83 1.2 garbled static u_int64_t
84 1.2 garbled in64(uint a)
85 1.2 garbled {
86 1.2 garbled union {
87 1.2 garbled double d;
88 1.2 garbled u_int64_t i;
89 1.2 garbled } u;
90 1.2 garbled double save, *dp = (double *)a;
91 1.2 garbled u_int32_t msr, nmsr;
92 1.2 garbled
93 1.2 garbled __asm volatile("mfmsr %0" : "=r"(msr));
94 1.2 garbled nmsr = (msr | PSL_FP) & ~(PSL_FE0 | PSL_FE1);
95 1.2 garbled __asm volatile("mtmsr %0" :: "r"(nmsr));
96 1.2 garbled __asm volatile("mfmsr %0" : "=r"(nmsr)); /* some interlock nonsense */
97 1.2 garbled __asm volatile(
98 1.2 garbled "stfd 0,%0\n\
99 1.2 garbled lfd 0,%1\n\
100 1.2 garbled stfd 0,%2\n\
101 1.2 garbled lfd 0,%0"
102 1.2 garbled : "=m"(save), "=m"(*dp)
103 1.2 garbled : "m"(u.d)
104 1.2 garbled );
105 1.2 garbled __asm volatile ("eieio; sync");
106 1.2 garbled __asm volatile("mtmsr %0" :: "r"(msr));
107 1.2 garbled return (u.i);
108 1.2 garbled }
109 1.2 garbled #endif
110 1.2 garbled
111 1.2 garbled static void
112 1.2 garbled out64(uint a, u_int64_t v)
113 1.2 garbled {
114 1.2 garbled union {
115 1.2 garbled double d;
116 1.2 garbled u_int64_t i;
117 1.2 garbled } u;
118 1.2 garbled double save, *dp = (double *)a;
119 1.2 garbled u_int32_t msr, nmsr;
120 1.2 garbled int s;
121 1.2 garbled
122 1.2 garbled s = splhigh();
123 1.2 garbled u.i = v;
124 1.2 garbled __asm volatile("mfmsr %0" : "=r"(msr));
125 1.2 garbled nmsr = (msr | PSL_FP) & ~(PSL_FE0 | PSL_FE1);
126 1.2 garbled __asm volatile("mtmsr %0" :: "r"(nmsr));
127 1.2 garbled __asm volatile("mfmsr %0" : "=r"(nmsr)); /* some interlock nonsense */
128 1.2 garbled __asm volatile(
129 1.2 garbled "stfd 0,%0\n\
130 1.2 garbled lfd 0,%2\n\
131 1.2 garbled stfd 0,%1\n\
132 1.2 garbled lfd 0,%0"
133 1.2 garbled : "=m"(save), "=m"(*dp)
134 1.2 garbled : "m"(u.d)
135 1.2 garbled );
136 1.2 garbled __asm volatile ("eieio; sync");
137 1.2 garbled __asm volatile("mtmsr %0" :: "r"(msr));
138 1.2 garbled splx(s);
139 1.2 garbled }
140 1.2 garbled
141 1.2 garbled static u_int8_t
142 1.2 garbled cs_io_read_1(struct cs_softc *sc, bus_size_t offs)
143 1.2 garbled {
144 1.2 garbled u_int32_t a, v;
145 1.2 garbled
146 1.2 garbled a = sc->sc_ioh + (offs << 2);
147 1.2 garbled v = in8(a);
148 1.2 garbled return v;
149 1.2 garbled }
150 1.2 garbled
151 1.2 garbled static u_int16_t
152 1.2 garbled cs_io_read_2(struct cs_softc *sc, bus_size_t offs)
153 1.2 garbled {
154 1.2 garbled u_int32_t a, v;
155 1.2 garbled
156 1.2 garbled a = sc->sc_ioh + (offs << 2);
157 1.2 garbled v = in16(a);
158 1.2 garbled return v;
159 1.2 garbled }
160 1.2 garbled
161 1.2 garbled static void
162 1.2 garbled cs_io_read_multi_2(struct cs_softc *sc, bus_size_t offs, u_int16_t *buf,
163 1.2 garbled bus_size_t cnt)
164 1.2 garbled {
165 1.2 garbled u_int32_t a, v;
166 1.2 garbled
167 1.2 garbled a = sc->sc_ioh + (offs << 2);
168 1.2 garbled while (cnt--) {
169 1.2 garbled v = in16(a);
170 1.2 garbled *buf++ = bswap16(v);
171 1.2 garbled }
172 1.2 garbled }
173 1.2 garbled
174 1.2 garbled static void
175 1.2 garbled cs_io_write_2(struct cs_softc *sc, bus_size_t offs, u_int16_t data)
176 1.2 garbled {
177 1.2 garbled u_int32_t a;
178 1.2 garbled u_int64_t v;
179 1.2 garbled
180 1.2 garbled a = sc->sc_ioh + (offs << 2);
181 1.2 garbled v = (u_int64_t)data << 48;
182 1.2 garbled out64(a, v);
183 1.2 garbled
184 1.2 garbled (void)in16(a); /* CPC700 write post bug */
185 1.2 garbled }
186 1.2 garbled
187 1.2 garbled static void
188 1.2 garbled cs_io_write_multi_2(struct cs_softc *sc, bus_size_t offs,
189 1.2 garbled const u_int16_t *buf, bus_size_t cnt)
190 1.2 garbled {
191 1.2 garbled u_int16_t v;
192 1.2 garbled double save, *dp;
193 1.2 garbled union {
194 1.2 garbled double d;
195 1.2 garbled u_int64_t i;
196 1.2 garbled } u;
197 1.2 garbled u_int32_t msr, nmsr;
198 1.2 garbled int s;
199 1.2 garbled
200 1.2 garbled dp = (double *)(sc->sc_ioh + (offs << 2));
201 1.2 garbled
202 1.2 garbled s = splhigh();
203 1.2 garbled __asm volatile("mfmsr %0" : "=r"(msr));
204 1.2 garbled nmsr = (msr | PSL_FP) & ~(PSL_FE0 | PSL_FE1);
205 1.2 garbled __asm volatile("mtmsr %0" :: "r"(nmsr));
206 1.2 garbled __asm volatile("mfmsr %0" : "=r"(nmsr)); /* some interlock nonsense */
207 1.2 garbled __asm volatile("stfd 0,%0" : "=m"(save));
208 1.2 garbled
209 1.2 garbled while (cnt--) {
210 1.2 garbled v = *buf++;
211 1.2 garbled v = bswap16(v);
212 1.2 garbled u.i = (u_int64_t)v << 48;
213 1.2 garbled __asm volatile("lfd 0,%1\nstfd 0,%0" : "=m"(*dp) : "m"(u.d) );
214 1.2 garbled __asm volatile ("eieio; sync");
215 1.2 garbled }
216 1.2 garbled __asm volatile("lfd 0,%0" :: "m"(save));
217 1.2 garbled __asm volatile("mtmsr %0" :: "r"(msr));
218 1.2 garbled splx(s);
219 1.2 garbled }
220 1.2 garbled
221 1.2 garbled static u_int16_t
222 1.2 garbled cs_mem_read_2(struct cs_softc *sc, bus_size_t offs)
223 1.2 garbled {
224 1.2 garbled panic("cs_mem_read_2");
225 1.2 garbled }
226 1.2 garbled
227 1.2 garbled static void
228 1.2 garbled cs_mem_write_2(struct cs_softc *sc, bus_size_t offs, u_int16_t data)
229 1.2 garbled {
230 1.2 garbled panic("cs_mem_write_2");
231 1.2 garbled }
232 1.2 garbled
233 1.2 garbled static void
234 1.2 garbled cs_mem_write_region_2(struct cs_softc *sc, bus_size_t offs,
235 1.2 garbled const u_int16_t *buf, bus_size_t cnt)
236 1.2 garbled {
237 1.2 garbled panic("cs_mem_write_region_2");
238 1.2 garbled }
239 1.2 garbled
240 1.2 garbled void
241 1.4 tsutsui cs_mainbus_attach(device_t parent, device_t self, void *aux)
242 1.2 garbled {
243 1.4 tsutsui struct cs_softc *sc = device_private(self);
244 1.2 garbled struct mainbus_attach_args *maa = aux;
245 1.2 garbled int media[1] = { IFM_ETHER | IFM_10_T };
246 1.2 garbled
247 1.2 garbled printf("\n");
248 1.2 garbled
249 1.4 tsutsui sc->sc_dev = self;
250 1.2 garbled sc->sc_iot = maa->mb_bt;
251 1.2 garbled sc->sc_memt = maa->mb_bt;
252 1.2 garbled sc->sc_irq = maa->mb_irq;
253 1.2 garbled
254 1.2 garbled if (bus_space_map(sc->sc_iot, PMPPC_CS_IO, CS8900_IOSIZE*4,
255 1.2 garbled 0, &sc->sc_ioh)) {
256 1.4 tsutsui printf("%s: failed to map io\n", device_xname(self));
257 1.2 garbled return;
258 1.2 garbled }
259 1.2 garbled
260 1.2 garbled cs_check_eeprom(sc);
261 1.2 garbled
262 1.2 garbled sc->sc_ih = intr_establish(sc->sc_irq, IST_LEVEL, IPL_NET, cs_intr, sc);
263 1.2 garbled if (!sc->sc_ih) {
264 1.2 garbled printf("%s: unable to establish interrupt\n",
265 1.4 tsutsui device_xname(self));
266 1.2 garbled goto fail;
267 1.2 garbled }
268 1.2 garbled
269 1.2 garbled sc->sc_cfgflags = CFGFLG_NOT_EEPROM;
270 1.2 garbled
271 1.2 garbled sc->sc_io_read_1 = cs_io_read_1;
272 1.2 garbled sc->sc_io_read_2 = cs_io_read_2;
273 1.2 garbled sc->sc_io_read_multi_2 = cs_io_read_multi_2;
274 1.2 garbled sc->sc_io_write_2 = cs_io_write_2;
275 1.2 garbled sc->sc_io_write_multi_2 = cs_io_write_multi_2;
276 1.2 garbled sc->sc_mem_read_2 = cs_mem_read_2;
277 1.2 garbled sc->sc_mem_write_2 = cs_mem_write_2;
278 1.2 garbled sc->sc_mem_write_region_2 = cs_mem_write_region_2;
279 1.2 garbled
280 1.2 garbled /*
281 1.2 garbled * We need interrupt on INTRQ0 from the CS8900 (that's what wired
282 1.2 garbled * to the UIC). The MI driver subtracts 10 from the irq, so
283 1.2 garbled * use 10 as the irq.
284 1.2 garbled */
285 1.2 garbled sc->sc_irq = 10;
286 1.2 garbled
287 1.2 garbled /* Use half duplex 10baseT. */
288 1.2 garbled if (cs_attach(sc, NULL, media, 1, IFM_ETHER | IFM_10_T)) {
289 1.4 tsutsui printf("%s: unable to attach\n", device_xname(self));
290 1.2 garbled goto fail;
291 1.2 garbled }
292 1.2 garbled
293 1.2 garbled return;
294 1.2 garbled
295 1.2 garbled fail:
296 1.2 garbled /* XXX disestablish, unmap */
297 1.2 garbled return;
298 1.2 garbled }
299 1.2 garbled
300 1.2 garbled
301 1.2 garbled /*
302 1.2 garbled * EEPROM initialization code.
303 1.2 garbled */
304 1.2 garbled
305 1.2 garbled static uint16_t default_eeprom_cfg[] =
306 1.2 garbled { 0xA100, 0x2020, 0x0300, 0x0000, 0x0000,
307 1.2 garbled 0x102C, 0x1000, 0x0008, 0x2158, 0x0000,
308 1.2 garbled 0x0000, 0x0000 };
309 1.2 garbled
310 1.2 garbled static uint16_t
311 1.2 garbled cs_readreg(struct cs_softc *sc, uint pp_offset)
312 1.2 garbled {
313 1.2 garbled cs_io_write_2(sc, PORT_PKTPG_PTR, pp_offset);
314 1.2 garbled (void)cs_io_read_2(sc, PORT_PKTPG_PTR);
315 1.2 garbled return (cs_io_read_2(sc, PORT_PKTPG_DATA));
316 1.2 garbled }
317 1.2 garbled
318 1.2 garbled static void
319 1.2 garbled cs_writereg(struct cs_softc *sc, uint pp_offset, uint16_t value)
320 1.2 garbled {
321 1.2 garbled cs_io_write_2(sc, PORT_PKTPG_PTR, pp_offset);
322 1.2 garbled (void)cs_io_read_2(sc, PORT_PKTPG_PTR);
323 1.2 garbled cs_io_write_2(sc, PORT_PKTPG_DATA, value);
324 1.2 garbled (void)cs_io_read_2(sc, PORT_PKTPG_DATA);
325 1.2 garbled }
326 1.2 garbled
327 1.2 garbled static int
328 1.2 garbled cs_wait_eeprom_ready(struct cs_softc *sc)
329 1.2 garbled {
330 1.2 garbled int ms;
331 1.2 garbled
332 1.2 garbled /*
333 1.2 garbled * Check to see if the EEPROM is ready, a timeout is used -
334 1.2 garbled * just in case EEPROM is ready when SI_BUSY in the
335 1.2 garbled * PP_SelfST is clear.
336 1.2 garbled */
337 1.2 garbled ms = 0;
338 1.2 garbled while(cs_readreg(sc, PKTPG_SELF_ST) & SELF_ST_SI_BUSY) {
339 1.2 garbled delay(1000);
340 1.2 garbled if (ms++ > 20)
341 1.2 garbled return 0;
342 1.2 garbled }
343 1.2 garbled return 1;
344 1.2 garbled }
345 1.2 garbled
346 1.2 garbled static void
347 1.2 garbled cs_wr_eeprom(struct cs_softc *sc, uint16_t offset, uint16_t data)
348 1.2 garbled {
349 1.2 garbled
350 1.2 garbled /* Check to make sure EEPROM is ready. */
351 1.2 garbled if (!cs_wait_eeprom_ready(sc)) {
352 1.4 tsutsui printf("%s: write EEPROM not ready\n",
353 1.4 tsutsui device_xname(sc->sc_dev));
354 1.2 garbled return;
355 1.2 garbled }
356 1.2 garbled
357 1.2 garbled /* Enable writing. */
358 1.2 garbled cs_writereg(sc, PKTPG_EEPROM_CMD, EEPROM_WRITE_ENABLE);
359 1.2 garbled
360 1.2 garbled /* Wait for WRITE_ENABLE command to complete. */
361 1.2 garbled if (!cs_wait_eeprom_ready(sc)) {
362 1.4 tsutsui printf("%s: EEPROM WRITE_ENABLE timeout",
363 1.4 tsutsui device_xname(sc->sc_dev));
364 1.2 garbled } else {
365 1.2 garbled /* Write data into EEPROM_DATA register. */
366 1.2 garbled cs_writereg(sc, PKTPG_EEPROM_DATA, data);
367 1.2 garbled delay(1000);
368 1.2 garbled cs_writereg(sc, PKTPG_EEPROM_CMD, EEPROM_CMD_WRITE | offset);
369 1.2 garbled
370 1.2 garbled /* Wait for WRITE_REGISTER command to complete. */
371 1.2 garbled if (!cs_wait_eeprom_ready(sc)) {
372 1.2 garbled printf("%s: EEPROM WRITE_REGISTER timeout\n",
373 1.4 tsutsui device_xname(sc->sc_dev));
374 1.2 garbled }
375 1.2 garbled }
376 1.2 garbled
377 1.2 garbled /* Disable writing. */
378 1.2 garbled cs_writereg(sc, PKTPG_EEPROM_CMD, EEPROM_WRITE_DISABLE);
379 1.2 garbled
380 1.2 garbled /* Wait for WRITE_DISABLE command to complete. */
381 1.2 garbled if (!cs_wait_eeprom_ready(sc)) {
382 1.4 tsutsui printf("%s: WRITE_DISABLE timeout\n", device_xname(sc->sc_dev));
383 1.2 garbled }
384 1.2 garbled }
385 1.2 garbled
386 1.2 garbled static uint16_t
387 1.2 garbled cs_rd_eeprom(struct cs_softc *sc, uint16_t offset)
388 1.2 garbled {
389 1.2 garbled
390 1.2 garbled if (!cs_wait_eeprom_ready(sc)) {
391 1.4 tsutsui printf("%s: read EEPROM not ready\n", device_xname(sc->sc_dev));
392 1.2 garbled return 0;
393 1.2 garbled }
394 1.2 garbled cs_writereg(sc, PKTPG_EEPROM_CMD, EEPROM_CMD_READ | offset);
395 1.2 garbled
396 1.2 garbled if (!cs_wait_eeprom_ready(sc)) {
397 1.4 tsutsui printf("%s: EEPROM_READ timeout\n", device_xname(sc->sc_dev));
398 1.2 garbled return 0;
399 1.2 garbled }
400 1.2 garbled return cs_readreg(sc, PKTPG_EEPROM_DATA);
401 1.2 garbled }
402 1.2 garbled
403 1.2 garbled static void
404 1.2 garbled cs_check_eeprom(struct cs_softc *sc)
405 1.2 garbled {
406 1.2 garbled uint8_t checksum;
407 1.2 garbled int i;
408 1.2 garbled uint16_t tmp;
409 1.2 garbled
410 1.2 garbled /*
411 1.2 garbled * If the SELFST[EEPROMOK] is set, then assume EEPROM configuration
412 1.2 garbled * is valid.
413 1.2 garbled */
414 1.2 garbled if (cs_readreg(sc, PKTPG_SELF_ST) & SELF_ST_EEP_OK) {
415 1.2 garbled printf("%s: EEPROM OK, skipping initialization\n",
416 1.4 tsutsui device_xname(sc->sc_dev));
417 1.2 garbled return;
418 1.2 garbled }
419 1.4 tsutsui printf("%s: updating EEPROM\n", device_xname(sc->sc_dev));
420 1.2 garbled
421 1.2 garbled /*
422 1.2 garbled * Calculate the size (in bytes) of the default config array and write
423 1.2 garbled * it to the lower byte of the array itself.
424 1.2 garbled */
425 1.2 garbled default_eeprom_cfg[0] |= sizeof(default_eeprom_cfg);
426 1.2 garbled
427 1.2 garbled /*
428 1.2 garbled * Read the MAC address from its Artesyn-specified offset in the EEPROM.
429 1.2 garbled */
430 1.2 garbled for (i = 0; i < 3; i++) {
431 1.2 garbled tmp = cs_rd_eeprom(sc, ATSN_EEPROM_MAC_OFFSET + i);
432 1.2 garbled default_eeprom_cfg[EEPROM_MAC + i] = bswap16(tmp);
433 1.2 garbled }
434 1.2 garbled
435 1.2 garbled /*
436 1.2 garbled * Program the EEPROM with our default configuration,
437 1.2 garbled * calculating checksum as we proceed.
438 1.2 garbled */
439 1.2 garbled checksum = 0;
440 1.2 garbled for (i = 0; i < sizeof(default_eeprom_cfg)/2 ; i++) {
441 1.2 garbled tmp = default_eeprom_cfg[i];
442 1.2 garbled cs_wr_eeprom(sc, i, tmp);
443 1.2 garbled checksum += tmp >> 8;
444 1.2 garbled checksum += tmp & 0xff;
445 1.2 garbled }
446 1.2 garbled
447 1.2 garbled /*
448 1.2 garbled * The CS8900a datasheet calls for the two's complement of the checksum
449 1.2 garbled * to be prgrammed in the most significant byte of the last word of the
450 1.2 garbled * header.
451 1.2 garbled */
452 1.2 garbled checksum = ~checksum + 1;
453 1.2 garbled cs_wr_eeprom(sc, i++, checksum << 8);
454 1.2 garbled /* write "end of data" flag */
455 1.2 garbled cs_wr_eeprom(sc, i, 0xffff);
456 1.2 garbled }
457