2 #include "include/assembly.h"
3 #include "include/options.h"
6 @ Exception defs taken from ARM DDI 0406B
9 interrupt_vector_table:
10 ivt_reset: b _start @ 0x00 Reset
11 ivt_undef: b Undef_Handler @ 0x04 #UD
12 ivt_svc: b SVC_Handler @ 0x08 SVC (used to be called SWI)
13 ivt_prefetch: b PrefetchAbort @ 0x0C Prefetch abort
14 ivt_data: b DataAbort @ 0x10 Data abort
15 ivt_unused: b . @ 0x14 Not Used
16 ivt_irq: b IRQHandler @ 0x18 IRQ
17 ivt_fiq: b . @ 0x1C FIQ (Fast interrupt)
25 ldr r0, =kernel_table0-KERNEL_BASE
26 mcr p15, 0, r0, c2, c0, 1 @ Set TTBR1 to r0
27 mcr p15, 0, r0, c2, c0, 0 @ Set TTBR0 to r0 too (for identity)
33 mcr p15, 0, r0, c2, c0, 2 @ Set TTCR to 1 (50/50 split)
39 mcr p15, 0, r0, c3, c0, 0 @ Set Domain 0 to Manager
45 mrc p15, 0, r0, c1, c0, 0
48 mcr p15, 0, r0, c1, c0, 0
50 @ HACK: Set ASID to non zero
58 @ Enable access faults on domains 0 & 1
59 mov r0, #0x55 @ 01010101b
60 mcr p15, 0, r0, c3, c0, 0
66 @ Check for security extensions
68 mrc p15, 0, r0, c0, c1, 1
72 mcrne p15, 0, r0, c12, c0, 0 @ Set the VBAR (brings exceptions into high memory)
74 mrceq p15, 0, r0, c1, c0, 0 @ Set SCTLR.V
76 mcreq p15, 0, r0, c1, c0, 0
81 @ Prepare for interrupts
83 ldr sp, =irqstack+0x1000 @ Set up stack
85 ldr sp, =abortstack+0x1000
100 .extern bss_size_div_4
111 ldr sp, =0x80000000-8 @ Set up stack (top of user range)
114 1: b 1b @ Infinite loop
116 .comm irqstack, 0x1000 @ ; 4KiB Stack
117 .comm abortstack, 0x1000 @ ; 4KiB Stack
119 .extern SyscallHandler
122 srsdb sp!, #19 @ Save state to stack
123 cpsie ifa, #19 @ Ensure we're in supervisor with interrupts enabled (should already be there)
136 ldr r4, =SyscallHandler
139 @ ldr r0, =csSyscallPrintRetAddr
140 @ ldr r1, [sp,#9*4+5*4]
145 pop {r0,r1} @ Ret/RetHi
146 add sp, #2*4 @ Saved r2/r3
149 rfeia sp! @ Pop state (actually RFEFD)
153 mov r1, sp @ Arguments
155 ldr r4, =ARMv7_int_HandleSyscalls
164 gpIRQHandler: .long 0
165 IRQ_saved_sp: .long 0
166 IRQ_saved_lr: .long 0
169 sub lr, #4 @ Adjust LR to the correct value
170 srsdb sp!, #19 @ Switch to supervisor mode (DDI0406B D1.6.5) (actually SRSFD)
180 @ Call the registered handler
187 rfeia sp! @ Pop state (actually RFEFD)
192 sub lr, #8 @ Adjust LR to the correct value
193 srsdb sp!, #23 @ Switch to supervisor mode (DDI0406B D1.6.5) (actually SRSFD)
197 @ Get the user's LR value (and push to stack)
198 cps #31 @ Go to system mode
200 cps #19 @ Go to supervisor
202 cps #23 @ back to exception
205 mov r3, #0 @ not a prefetch abort
206 mrc p15, 0, r2, c5, c0, 0 @ Read DFSR (Data Fault Status Register) to R2
207 mrc p15, 0, r1, c6, c0, 0 @ Read DFAR (Data Fault Address Register) into R1
209 ldr r4, =MM_PageFault
211 add sp, #8 @ Undo push of the user/system LR
214 rfeia sp! @ Pop state (actually RFEFD)
218 sub lr, #4 @ Adjust LR to the correct value
219 srsdb sp!, #23 @ Switch to supervisor mode (DDI0406B D1.6.5) (actually SRSFD)
224 @ Get the user's LR value (and push to stack)
225 cps #31 @ Go to system mode
227 cps #23 @ back to supervisor
230 mrc p15, 0, r2, c5, c0, 1 @ Read IFSR (Instruction Fault Status Register) into R3
231 mrc p15, 0, r1, c6, c0, 2 @ Read IFAR (Instruction Fault Address Register) into R3
233 mov r3, #1 @ IS a prefetch abort
234 ldr r4, =MM_PageFault
236 add sp, #4 @ Undo push of the user LR
239 rfeia sp! @ Pop state (actually RFEFD)
255 .asciz "Data Abort - %p accessed %p, DFSR=%x Unk:%x Unk:%x"
257 .asciz "Prefetch Abort at %p, IFSR=%x, UserLR:0x%x"
258 csSyscallPrintRetAddr:
259 .asciz "Syscall ret to %p"
265 .long 0x00000402 @ Identity map the first 1 MiB
269 .long user_table1_map + 0x000 - KERNEL_BASE + 1 @ 0x7FC00000
270 .long user_table1_map + 0x400 - KERNEL_BASE + 1 @ 0x7FD00000
271 .long user_table1_map + 0x800 - KERNEL_BASE + 1 @ KStacks
272 .long user_table1_map + 0xC00 - KERNEL_BASE + 1
273 @ 0x80000000 - User/Kernel split
274 .long 0x00000402 @ Map first 4 MiB to 2GiB (KRW only)
278 .rept 0xF00 - 0x800 - 4
282 .long PCI_PADDR + 0*(1 << 20) + 0x402 @ Map PCI config space
283 .long PCI_PADDR + 1*(1 << 20) + 0x402
284 .long PCI_PADDR + 2*(1 << 20) + 0x402
285 .long PCI_PADDR + 3*(1 << 20) + 0x402
286 .long PCI_PADDR + 4*(1 << 20) + 0x402
287 .long PCI_PADDR + 5*(1 << 20) + 0x402
288 .long PCI_PADDR + 6*(1 << 20) + 0x402
289 .long PCI_PADDR + 7*(1 << 20) + 0x402
290 .long PCI_PADDR + 8*(1 << 20) + 0x402
291 .long PCI_PADDR + 9*(1 << 20) + 0x402
292 .long PCI_PADDR + 10*(1 << 20) + 0x402
293 .long PCI_PADDR + 11*(1 << 20) + 0x402
294 .long PCI_PADDR + 12*(1 << 20) + 0x402
295 .long PCI_PADDR + 13*(1 << 20) + 0x402
296 .long PCI_PADDR + 14*(1 << 20) + 0x402
297 .long PCI_PADDR + 15*(1 << 20) + 0x402
303 .long hwmap_table_0 + 0x000 - KERNEL_BASE + 1
304 .long hwmap_table_0 + 0x400 - KERNEL_BASE + 1
305 .long hwmap_table_0 + 0x800 - KERNEL_BASE + 1
306 .long hwmap_table_0 + 0xC00 - KERNEL_BASE + 1
307 .rept 0xFF8 - 0xF00 - 16 - 4
311 .long kernel_table1_map + 0x000 - KERNEL_BASE + 1
312 .long kernel_table1_map + 0x400 - KERNEL_BASE + 1
313 .long kernel_table1_map + 0x800 - KERNEL_BASE + 1
314 .long kernel_table1_map + 0xC00 - KERNEL_BASE + 1
315 .long kernel_exception_map + 0x000 - KERNEL_BASE + 1
316 .long kernel_exception_map + 0x400 - KERNEL_BASE + 1
317 .long kernel_exception_map + 0x800 - KERNEL_BASE + 1
318 .long kernel_exception_map + 0xC00 - KERNEL_BASE + 1
321 .globl user_table1_map
322 @ User table1 data table (only the first half is needed)
323 @ - Abused to provide kernel stacks in the unused half of the table
324 user_table1_map: @ Size = 4KiB (only 2KiB used)
328 .long user_table1_map - KERNEL_BASE + 0x13 @ ...1FF000 = 0x7FDFF000
330 .long kernel_table0 + 0x0000 - KERNEL_BASE + 0x13 @ ...200000 = 0x7FE00000
331 .long kernel_table0 + 0x1000 - KERNEL_BASE + 0x13 @ ...201000 = 0x7FE01000
332 .rept (0x800/4)-(MM_KSTACK_SIZE/0x1000)-2
335 #if MM_KSTACK_SIZE != 0x2000
336 #error Kernel stack size not changed in start.S
338 .long stack + 0x0000 - KERNEL_BASE + 0x13 @ Kernel Stack
339 .long stack + 0x1000 - KERNEL_BASE + 0x13 @
341 .globl kernel_table1_map
342 kernel_table1_map: @ Size = 4KiB
346 .long hwmap_table_0 - KERNEL_BASE + 0x13
347 .rept 0xFF8/4 - (0xF00+16)/4 - 1
350 .long kernel_table1_map - KERNEL_BASE + 0x13
351 .long kernel_exception_map - KERNEL_BASE + 0x13
356 .long UART0_PADDR + 0x13 @ UART0
360 .globl kernel_exception_map
361 kernel_exception_map:
366 @ Align to nearly the end
370 .long 0x212 @ Map first page for exceptions (Kernel RO, Execute)
374 .long gUsertextPhysStart + 0x22 @ User .text (User RO, Kernel RW, because both is COW)
379 .space MM_KSTACK_SIZE, 0 @ Original kernel stack
381 // vim: ts=8 ft=armv7