xref: /plan9/sys/src/9/pcboot/mem.h (revision 12009bff671a91993ae58f16dab833e809f4a6f3)
1 /*
2  * Memory and machine-specific definitions.  Used in C and assembler.
3  */
4 
5 /*
6  * Sizes
7  */
8 #define	BI2BY		8			/* bits per byte */
9 #define	BI2WD		32			/* bits per word */
10 #define	BY2WD		4			/* bytes per word */
11 #define	BY2V		8			/* bytes per double word */
12 #define	BY2PG		4096			/* bytes per page */
13 #define	WD2PG		(BY2PG/BY2WD)		/* words per page */
14 #define	BY2XPG		(4096*1024)		/* bytes per big page */
15 #define	PGSHIFT		12			/* log(BY2PG) */
16 #define CACHELINESZ	32			/* pentium & later */
17 #define	BLOCKALIGN	8
18 
19 #define	MAXMACH		1			/* max # cpus system can run */
20 /*
21  * we use a larger-than-normal kernel stack in the bootstraps as we have
22  * significant arrays (buffers) on the stack.  we typically consume about
23  * 4.5K of stack.
24  */
25 #define KSTACK		(4*BY2PG)		/* Size of kernel stack */
26 #define MACHSIZE	BY2PG
27 
28 /*
29  * Time
30  */
31 #define	HZ		(100)			/* clock frequency */
32 #define	MS2HZ		(1000/HZ)		/* millisec per clock tick */
33 #define	TK2SEC(t)	((t)/HZ)		/* ticks to seconds */
34 
35 /*
36  *  Address spaces
37  *
38  *  Kernel is at 2GB-4GB
39  */
40 #define	KZERO		0x80000000		/* base of kernel address space */
41 #define	KSEGM		0xF0000000
42 #define	VPT		(KZERO-VPTSIZE)
43 #define	VPTSIZE		BY2XPG
44 #define	NVPT		(VPTSIZE/BY2WD)
45 #define	KMAP		(VPT-KMAPSIZE)
46 #define	KMAPSIZE	BY2XPG
47 #define	VMAP		(KMAP-VMAPSIZE)
48 #define	VMAPSIZE	(0x10000000-VPTSIZE-KMAPSIZE)
49 #define	UZERO		0			/* base of user address space */
50 #define	UTZERO		(UZERO+BY2PG)		/* first address in user text */
51 #define UTROUND(t)	ROUNDUP((t), BY2PG)
52 #define	USTKTOP		(VMAP-BY2PG)		/* byte just beyond user stack */
53 #define	USTKSIZE	(16*1024*1024)		/* size of user stack */
54 #define	TSTKTOP		(USTKTOP-USTKSIZE)	/* end of new stack in sysexec */
55 #define	TSTKSIZ 	100			/* pages in new stack; limits exec args */
56 
57 /*
58  * Fundamental addresses - bottom 64kB saved for return to real mode
59  *
60  * we need some fixed address space for things that normally fit below the
61  * kernel and some of it needs to be addressible from real mode, thus under 1MB.
62  *
63  * pxe loading starts us at 0x7c00 and non-pxe loading starts us at 0x10000.
64  *
65  * this assertion must hold: PDX(TMPADDR) == PDX(MACHADDR).
66  * see realmode0.s for a description of the Chinese puzzle.
67  */
68 /* first 1K is real-mode IVT (vectors) */
69 /* next 256 bytes are bios data area (bda) */
70 /* 0x500 to 0x800 unused [768] */
71 /*
72  * RMCODE should be the lowest address used in real mode.
73  * all real-mode buffers, etc. should follow it.
74  */
75 #define RMCODE		(KZERO+0x800)	/* copy of initial KTZERO [2K, magic] */
76 #define	REBOOTADDR	(RMCODE-KZERO)	/* reboot code - physical address [128] */
77 #define RMSIZE		2048
78 /* 0x1000 to 0x1200 unused [512] */
79 /* CONFADDR must match def'n in kernel being loaded */
80 #define	CONFADDR	(KZERO+0x1200)	/* cfg passed to kernel [3.5K, fixed] */
81 #define BIOSXCHG	(KZERO+0x2000)	/* BIOS data exchange [2K+32] */
82 /* 0x2820 to 0x2900 unused [224] */
83 #define	RMUADDR		(KZERO+0x2900)	/* real mode Ureg [128 (76 actual)] */
84 /* 0x2980 to 0x3000 unused [1664] */
85 #define IDTADDR		(KZERO+0x3000)	/* protected-mode idt [2K] */
86 /* 0x3800 to 0x4000 unused [2K] */
87 
88 /* we only use one processor for bootstrapping, so merge MACHADDR & CPU0MACH */
89 #define	MACHADDR	(KZERO+0x4000)	/* as seen by current processor */
90 #define	CPU0MACH	MACHADDR	/* Mach for bootstrap processor */
91 #define	CPU0GDT		(KZERO+0x5000)	/* bootstrap processor GDT after Mach */
92 #define	TMPADDR		(KZERO+0x6000)	/* used for temporary mappings */
93 /* 0x7000—0x7800 unused [2K], could be extra real-mode stack */
94 #define PXEBASE 	0x7c00		/* pxe loads us here */
95 #define RMSTACK 	PXEBASE		/* real phys. stack base [1K below] */
96 #define PBSBASE		0x10000		/* pbs loads us here (at 64K) */
97 
98 /*
99  * we used to use 9boot's `end', rounded up, but that was when the boot loader
100  * was in the first 640K; now end is up around 10MB (at least for 9boot).
101  * various machines nibble away at the top of the lowest 640K.
102  */
103 #define BIOSTABLES	(512*1024)
104 // #define BIOSTABLES	(600*1024)	/* fails on amd64 */
105 // #define BIOSTABLES	0x3800		/* 2K: fails on amd64 */
106 
107 #define Bootkernaddr	(9*MB)	/* where to put decompressed boot kernel */
108 #define Bootkernmax	(4*MB)	/* max size */
109 #define Unzipbuf	(13*MB)
110 #define Mallocbase	(16*MB)
111 /*
112  * MemMin is what the bootstrap code in l*.s has already mapped;
113  * MemMax is the limit of physical memory to scan.
114  */
115 #define MemMin		(20*MB)	/* don't have PTEs for more allocated yet */
116 #define MemMax		(512*MB) /* allow for huge 10gbe buffers */
117 
118 #define Lowmemsz	(640*KB)
119 
120 #define LOWPTEPAGES	(MemMin / (4*MB))
121 
122 #define Kernelmax	(8*MB)	/* max size of real kernel, not an address */
123 
124 /*
125  *  known x86 segments (in GDT) and their selectors
126  */
127 #define	NULLSEG	0	/* null segment */
128 #define	KDSEG	1	/* kernel data/stack */
129 #define	KESEG	2	/* kernel executable */
130 #define	UDSEG	3	/* user data/stack */
131 #define	UESEG	4	/* user executable */
132 #define	TSSSEG	5	/* task segment */
133 #define	APMCSEG		6	/* APM code segment */
134 #define	APMCSEG16	7	/* APM 16-bit code segment */
135 #define	APMDSEG		8	/* APM data segment */
136 #define	KESEG16		9	/* kernel executable 16-bit */
137 #define	NGDT		10	/* number of GDT entries required */
138 /* #define	APM40SEG	8	/* APM segment 0x40 */
139 
140 #define	SELGDT	(0<<2)	/* selector is in gdt */
141 #define	SELLDT	(1<<2)	/* selector is in ldt */
142 
143 #define	SELECTOR(i, t, p)	(((i)<<3) | (t) | (p))
144 
145 #define	NULLSEL	SELECTOR(NULLSEG, SELGDT, 0)
146 #define	KDSEL	SELECTOR(KDSEG, SELGDT, 0)
147 #define	KESEL	SELECTOR(KESEG, SELGDT, 0)
148 #define	UESEL	SELECTOR(UESEG, SELGDT, 3)
149 #define	UDSEL	SELECTOR(UDSEG, SELGDT, 3)
150 #define	TSSSEL	SELECTOR(TSSSEG, SELGDT, 0)
151 #define	APMCSEL 	SELECTOR(APMCSEG, SELGDT, 0)
152 #define	APMCSEL16	SELECTOR(APMCSEG16, SELGDT, 0)
153 #define	APMDSEL		SELECTOR(APMDSEG, SELGDT, 0)
154 /* #define	APM40SEL	SELECTOR(APM40SEG, SELGDT, 0) */
155 
156 /*
157  *  fields in segment descriptors
158  */
159 #define	SEGDATA	(0x10<<8)	/* data/stack segment */
160 #define	SEGEXEC	(0x18<<8)	/* executable segment */
161 #define	SEGTSS	(0x9<<8)	/* TSS segment */
162 #define	SEGCG	(0x0C<<8)	/* call gate */
163 #define	SEGIG	(0x0E<<8)	/* interrupt gate */
164 #define	SEGTG	(0x0F<<8)	/* trap gate */
165 #define	SEGTYPE	(0x1F<<8)
166 
167 #define	SEGP	(1<<15)		/* segment present */
168 #define	SEGPL(x) ((x)<<13)	/* priority level */
169 #define	SEGB	(1<<22)		/* granularity 1==4k (for expand-down) */
170 #define	SEGG	(1<<23)		/* granularity 1==4k (for other) */
171 #define	SEGE	(1<<10)		/* expand down */
172 #define	SEGW	(1<<9)		/* writable (for data/stack) */
173 #define	SEGR	(1<<9)		/* readable (for code) */
174 #define	SEGD	(1<<22)		/* default 1==32bit (for code) */
175 
176 /*
177  *  virtual MMU
178  */
179 #define	PTEMAPMEM	(1024*1024)
180 #define	PTEPERTAB	(PTEMAPMEM/BY2PG)
181 #define	SEGMAPSIZE	1984
182 #define	SSEGMAPSIZE	16
183 #define	PPN(x)		((x)&~(BY2PG-1))
184 
185 /*
186  *  physical MMU
187  */
188 #define	PTEVALID	(1<<0)
189 #define	PTEWT		(1<<3)
190 #define	PTEUNCACHED	(1<<4)
191 #define	PTEWRITE	(1<<1)
192 #define	PTERONLY	(0<<1)
193 #define	PTEKERNEL	(0<<2)
194 #define	PTEUSER		(1<<2)
195 #define	PTESIZE		(1<<7)
196 #define	PTEGLOBAL	(1<<8)
197 
198 /* CR0 */
199 #define PG	0x80000000
200 
201 /*
202  * Macros for calculating offsets within the page directory base
203  * and page tables.
204  */
205 #define	PDX(va)		((((ulong)(va))>>22) & 0x03FF)
206 #define	PTX(va)		((((ulong)(va))>>12) & 0x03FF)
207 
208 #define	getpgcolor(a)	0
209 
210