| /* The head-file for the Shark |
| * by Alexander Schulz |
| * |
| * Does the following: |
| * - get the memory layout from firmware. This can only be done as long as the mmu |
| * is still on. |
| * - switch the mmu off, so we have physical addresses |
| * - copy the kernel to 0x08508000. This is done to have a fixed address where the |
| * C-parts (misc.c) are executed. This address must be known at compile-time, |
| * but the load-address of the kernel depends on how much memory is installed. |
| * - Jump to this location. |
| * - Set r8 with 0, r7 with the architecture ID for head.S |
| */ |
| |
| #include <linux/linkage.h> |
| |
| #include <asm/assembler.h> |
| |
| .section ".start", "ax" |
| |
| b __beginning |
| |
| __ofw_data: .long 0 @ the number of memory blocks |
| .space 128 @ (startaddr,size) ... |
| .space 128 @ bootargs |
| .align |
| |
| __beginning: mov r4, r0 @ save the entry to the firmware |
| |
| mov r0, #0xC0 @ disable irq and fiq |
| mov r1, r0 |
| mrs r3, cpsr |
| bic r2, r3, r0 |
| eor r2, r2, r1 |
| msr cpsr_c, r2 |
| |
| mov r0, r4 @ get the Memory layout from firmware |
| adr r1, __ofw_data |
| add r2, r1, #4 |
| mov lr, pc |
| b ofw_init |
| mov r1, #0 |
| |
| adr r2, __mmu_off @ calculate physical address |
| sub r2, r2, #0xf0000000 @ openprom maps us at f000 virt, 0e50 phys |
| adr r0, __ofw_data |
| ldr r0, [r0, #4] |
| add r2, r2, r0 |
| add r2, r2, #0x00500000 |
| |
| mrc p15, 0, r3, c1, c0 |
| bic r3, r3, #0xC @ Write Buffer and DCache |
| bic r3, r3, #0x1000 @ ICache |
| mcr p15, 0, r3, c1, c0 @ disabled |
| |
| mov r0, #0 |
| mcr p15, 0, r0, c7, c7 @ flush I,D caches on v4 |
| mcr p15, 0, r0, c7, c10, 4 @ drain write buffer on v4 |
| mcr p15, 0, r0, c8, c7 @ flush I,D TLBs on v4 |
| |
| bic r3, r3, #0x1 @ MMU |
| mcr p15, 0, r3, c1, c0 @ disabled |
| |
| mov pc, r2 |
| |
| __copy_target: .long 0x08508000 |
| __copy_end: .long 0x08608000 |
| |
| .word _start |
| .word __bss_start |
| |
| .align |
| __temp_stack: .space 128 |
| |
| __mmu_off: |
| adr r0, __ofw_data |
| ldr r0, [r0, #4] |
| orr r0, r0, #0x00600000 |
| |
| ldr r1, __copy_end |
| ldr r3, __copy_target |
| |
| /* r0 = 0x0e600000 (current end of kernelcode) |
| * r3 = 0x08508000 (where it should begin) |
| * r1 = 0x08608000 (end of copying area, 1MB) |
| * The kernel is compressed, so 1 MB should be enough. |
| * copy the kernel to the beginning of physical memory |
| * We start from the highest address, so we can copy |
| * from 0x08500000 to 0x08508000 if we have only 8MB |
| */ |
| |
| |
| __Copy: ldr r2, [r0], #-4 |
| str r2, [r1], #-4 |
| teq r1, r3 |
| bne __Copy |
| /* and jump to it */ |
| adr r2, __go_on |
| adr r0, __ofw_data |
| ldr r0, [r0, #4] |
| sub r2, r2, r0 |
| sub r2, r2, #0x00500000 |
| ldr r0, __copy_target |
| add r2, r2, r0 |
| mov pc, r2 |
| |
| __go_on: |
| adr sp, __temp_stack |
| add sp, sp, #128 |
| adr r0, __ofw_data |
| mov lr, pc |
| b create_params |
| |
| mov r8, #0 |
| mov r7, #15 |