| |
| #define MEM_END 0x00800000 /* Memory size 8Mb */ |
| |
| #undef CRT_DEBUG |
| |
| .macro PUTC CHAR |
| #ifdef CRT_DEBUG |
| moveq #\CHAR, %d7 |
| jsr putc |
| #endif |
| .endm |
| |
| .global _start |
| .global _rambase |
| .global _ramvec |
| .global _ramstart |
| .global _ramend |
| |
| .data |
| |
| /* |
| * Set up the usable of RAM stuff |
| */ |
| _rambase: |
| .long 0 |
| _ramvec: |
| .long 0 |
| _ramstart: |
| .long 0 |
| _ramend: |
| .long 0 |
| |
| .text |
| |
| _start: |
| |
| /* |
| * Setup initial stack |
| */ |
| /* disable all interrupts */ |
| movew #0x2700, %sr |
| movel #-1, 0xfffff304 |
| movel #MEM_END-4, %sp |
| |
| PUTC '\r' |
| PUTC '\n' |
| PUTC 'A' |
| PUTC 'B' |
| |
| /* |
| * Determine end of RAM |
| */ |
| |
| movel #MEM_END, %a0 |
| movel %a0, _ramend |
| |
| PUTC 'C' |
| |
| /* |
| * Move ROM filesystem above bss :-) |
| */ |
| |
| moveal #_sbss, %a0 /* romfs at the start of bss */ |
| moveal #_ebss, %a1 /* Set up destination */ |
| movel %a0, %a2 /* Copy of bss start */ |
| |
| movel 8(%a0), %d1 /* Get size of ROMFS */ |
| addql #8, %d1 /* Allow for rounding */ |
| andl #0xfffffffc, %d1 /* Whole words */ |
| |
| addl %d1, %a0 /* Copy from end */ |
| addl %d1, %a1 /* Copy from end */ |
| movel %a1, _ramstart /* Set start of ram */ |
| |
| 1: |
| movel -(%a0), %d0 /* Copy dword */ |
| movel %d0, -(%a1) |
| cmpl %a0, %a2 /* Check if at end */ |
| bne 1b |
| |
| PUTC 'D' |
| |
| /* |
| * Initialize BSS segment to 0 |
| */ |
| |
| lea _sbss, %a0 |
| lea _ebss, %a1 |
| |
| /* Copy 0 to %a0 until %a0 == %a1 */ |
| 2: cmpal %a0, %a1 |
| beq 1f |
| clrl (%a0)+ |
| bra 2b |
| 1: |
| |
| PUTC 'E' |
| |
| /* |
| * Load the current task pointer and stack |
| */ |
| |
| lea init_thread_union, %a0 |
| lea 0x2000(%a0), %sp |
| |
| PUTC 'F' |
| PUTC '\r' |
| PUTC '\n' |
| |
| /* |
| * Go |
| */ |
| |
| jmp start_kernel |
| |
| /* |
| * Local functions |
| */ |
| |
| #ifdef CRT_DEBUG |
| putc: |
| moveb %d7, 0xfffff907 |
| 1: |
| movew 0xfffff906, %d7 |
| andw #0x2000, %d7 |
| beq 1b |
| rts |
| #endif |
