X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=arch%2Farm%2Flib%2Fcrt0.S;h=8415f77e1b1e02b5159b3059dd19c572ccb16098;hb=73eed452b9c9827474c0789c30729dca6fcf061d;hp=ac54b9359aea3b4954004e1b7805445ff0508b41;hpb=5c8d5b6fc15fc2c52d74c266d9fe6eb5f75cbcb4;p=oweals%2Fu-boot.git diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S index ac54b9359a..8415f77e1b 100644 --- a/arch/arm/lib/crt0.S +++ b/arch/arm/lib/crt0.S @@ -9,6 +9,9 @@ #include #include #include +#ifdef CONFIG_CPU_V7M +#include +#endif /* * This file handles the target-independent stages of the U-Boot @@ -22,7 +25,8 @@ * the GD ('global data') structure, both located in some readily * available RAM (SRAM, locked cache...). In this context, VARIABLE * global data, initialized or not (BSS), are UNAVAILABLE; only - * CONSTANT initialized data are available. + * CONSTANT initialized data are available. GD should be zeroed + * before board_init_f() is called. * * 2. Call board_init_f(). This function prepares the hardware for * execution from system RAM (DRAM, DDR...) As system RAM may not @@ -31,24 +35,29 @@ * data include the relocation destination, the future stack, and * the future GD location. * - * (the following applies only to non-SPL builds) - * * 3. Set up intermediate environment where the stack and GD are the * ones allocated by board_init_f() in system RAM, but BSS and * initialized non-const data are still not available. * - * 4. Call relocate_code(). This function relocates U-Boot from its - * current location into the relocation destination computed by - * board_init_f(). + * 4a.For U-Boot proper (not SPL), call relocate_code(). This function + * relocates U-Boot from its current location into the relocation + * destination computed by board_init_f(). + * + * 4b.For SPL, board_init_f() just returns (to crt0). There is no + * code relocation in SPL. * * 5. Set up final environment for calling board_init_r(). This * environment has BSS (initialized to 0), initialized non-const * data (initialized to their intended value), and stack in system - * RAM. GD has retained values set by board_init_f(). Some CPUs - * have some work left to do at this point regarding memory, so - * call c_runtime_cpu_setup. + * RAM (for SPL moving the stack and GD into RAM is optional - see + * CONFIG_SPL_STACK_R). GD has retained values set by board_init_f(). + * + * 6. For U-Boot proper (not SPL), some CPUs have some work left to do + * at this point regarding memory, so call c_runtime_cpu_setup. * - * 6. Branch to board_init_r(). + * 7. Branch to board_init_r(). + * + * For more information see 'Board Initialisation Flow in README. */ /* @@ -66,10 +75,20 @@ ENTRY(_main) #else ldr sp, =(CONFIG_SYS_INIT_SP_ADDR) #endif +#if defined(CONFIG_CPU_V7M) /* v7M forbids using SP as BIC destination */ + mov r3, sp + bic r3, r3, #7 + mov sp, r3 +#else bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ - sub sp, #GD_SIZE /* allocate one GD above SP */ - bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ - mov r9, sp /* GD is above SP */ +#endif + mov r0, sp + bl board_init_f_alloc_reserve + mov sp, r0 + /* set up gd here, outside any C code */ + mov r9, r0 + bl board_init_f_init_reserve + mov r0, #0 bl board_init_f @@ -82,42 +101,79 @@ ENTRY(_main) */ ldr sp, [r9, #GD_START_ADDR_SP] /* sp = gd->start_addr_sp */ +#if defined(CONFIG_CPU_V7M) /* v7M forbids using SP as BIC destination */ + mov r3, sp + bic r3, r3, #7 + mov sp, r3 +#else bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ +#endif ldr r9, [r9, #GD_BD] /* r9 = gd->bd */ sub r9, r9, #GD_SIZE /* new GD is below bd */ adr lr, here ldr r0, [r9, #GD_RELOC_OFF] /* r0 = gd->reloc_off */ add lr, lr, r0 +#if defined(CONFIG_CPU_V7M) + orr lr, #1 /* As required by Thumb-only */ +#endif ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ b relocate_code here: +/* + * now relocate vectors + */ + + bl relocate_vectors /* Set up final (full) environment */ bl c_runtime_cpu_setup /* we still call old routine here */ - +#endif +#if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_FRAMEWORK) +# ifdef CONFIG_SPL_BUILD + /* Use a DRAM stack for the rest of SPL, if requested */ + bl spl_relocate_stack_gd + cmp r0, #0 + movne sp, r0 + movne r9, r0 +# endif ldr r0, =__bss_start /* this is auto-relocated! */ - ldr r1, =__bss_end /* this is auto-relocated! */ +#ifdef CONFIG_USE_ARCH_MEMSET + ldr r3, =__bss_end /* this is auto-relocated! */ + mov r1, #0x00000000 /* prepare zero to clear BSS */ + + subs r2, r3, r0 /* r2 = memset len */ + bl memset +#else + ldr r1, =__bss_end /* this is auto-relocated! */ mov r2, #0x00000000 /* prepare zero to clear BSS */ clbss_l:cmp r0, r1 /* while not at end of BSS */ +#if defined(CONFIG_CPU_V7M) + itt lo +#endif strlo r2, [r0] /* clear 32-bit BSS word */ addlo r0, r0, #4 /* move to next */ blo clbss_l +#endif +#if ! defined(CONFIG_SPL_BUILD) bl coloured_LED_init bl red_led_on - +#endif /* call board_init_r(gd_t *id, ulong dest_addr) */ mov r0, r9 /* gd_t */ ldr r1, [r9, #GD_RELOCADDR] /* dest_addr */ /* call board_init_r */ +#if defined(CONFIG_SYS_THUMB_BUILD) + ldr lr, =board_init_r /* this is auto-relocated! */ + bx lr +#else ldr pc, =board_init_r /* this is auto-relocated! */ - +#endif /* we should not return here. */ - #endif ENDPROC(_main)