From: hackbard Date: Thu, 20 Sep 2007 21:53:07 +0000 (+0200) Subject: irq/fiq enabled, copy vectors if code resides in ram X-Git-Url: https://hackdaworld.org/gitweb/?a=commitdiff_plain;h=5289778b44c03bc85a970ab2ece27e1888d47558;p=my-code%2Farm.git irq/fiq enabled, copy vectors if code resides in ram --- diff --git a/betty/startup.s b/betty/startup.s index d393d32..18006aa 100644 --- a/betty/startup.s +++ b/betty/startup.s @@ -41,6 +41,8 @@ .equ fiq_disable, 0x40 .equ irq_disable, 0x80 +.equ vic_vect_addr, 0xfffff030 + # # the startup code # @@ -57,6 +59,8 @@ # - that's the vectored address register # - the vic put in there the address of our service routine +exception_vectors: + ldr pc, handler_reset ldr pc, handler_undef_instruction ldr pc, handler_soft_ir @@ -64,6 +68,7 @@ ldr pc, handler_data_abort nop ldr pc, [pc, #-0xff0] + #ldr pc, handler_irq ldr pc, handler_fiq handler_reset: .word handle_reset @@ -71,6 +76,7 @@ handler_undef_instruction: .word interrupt_handler_undef_instruction handler_soft_ir: .word interrupt_handler_soft_ir handler_prefetch_abort: .word interrupt_handler_prefetch_abort handler_data_abort: .word interrupt_handler_data_abort +handler_irq: .word vic_vect_addr handler_fiq: .word interrupt_handler_fiq # reset handling goes here @@ -108,6 +114,9 @@ handle_reset: ldr r0, =stack_limit mov sl, r0 + # enable irq and fiq + msr cpsr_c, #mode_system + # copy data section (only if we are in flash <=> _etext != _data) ldr r1, =_etext @@ -115,7 +124,7 @@ handle_reset: ldr r3, =_edata cmp r1, r2 - beq start_of_c_code + beq copy_exception_vectors copy_data_loop: @@ -123,6 +132,18 @@ copy_data_loop: ldrlo r0, [r1], #4 strlo r0, [r2], #4 blo copy_data_loop + b start_of_c_code + + # copy exception vectors (only if we are in ram <=> _etext = _data) + +copy_exception_vectors: + + mov r0, #sram_addr + ldr r1, =exception_vectors + ldmia r1!, {r2-r9} + stmia r0!, {r2-r9} + ldmia r1!, {r2-r8} + stmia r0!, {r2-r8} # jump to c code