diff options
| -rw-r--r-- | arch/arm/cpu/arm926ejs/mx27/Makefile | 4 | ||||
| -rw-r--r-- | arch/arm/cpu/arm926ejs/mx27/relocate.S | 51 | ||||
| -rw-r--r-- | arch/arm/lib/crt0.S | 5 | ||||
| -rw-r--r-- | arch/arm/lib/relocate.S | 69 |
4 files changed, 101 insertions, 28 deletions
diff --git a/arch/arm/cpu/arm926ejs/mx27/Makefile b/arch/arm/cpu/arm926ejs/mx27/Makefile index 4976bbb..0edf144 100644 --- a/arch/arm/cpu/arm926ejs/mx27/Makefile +++ b/arch/arm/cpu/arm926ejs/mx27/Makefile @@ -5,3 +5,7 @@ # SPDX-License-Identifier: GPL-2.0+ obj-y = generic.o reset.o timer.o + +ifndef CONFIG_SPL_BUILD +obj-y += relocate.o +endif diff --git a/arch/arm/cpu/arm926ejs/mx27/relocate.S b/arch/arm/cpu/arm926ejs/mx27/relocate.S new file mode 100644 index 0000000..0c4b272 --- /dev/null +++ b/arch/arm/cpu/arm926ejs/mx27/relocate.S @@ -0,0 +1,51 @@ +/* + * relocate - i.MX27-specific vector relocation + * + * Copyright (c) 2013 Albert ARIBAUD <albert.u.boot@aribaud.net> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <asm-offsets.h> +#include <config.h> +#include <linux/linkage.h> + +/* + * The i.MX27 SoC is very specific with respect to exceptions: it + * does not provide RAM at the high vectors address (0xFFFF0000), + * thus only the low address (0x00000000) is useable; but that is + * in ROM. Therefore, vectors cannot be changed at all. + * + * However, these ROM-based vectors actually just perform indirect + * calls through pointers located in RAM at SoC-specific addresses, + * as follows: + * + * Offset Exception Use by ROM code + * 0x00000000 reset indirect branch to [0x00000014] + * 0x00000004 undefined instruction indirect branch to [0xfffffef0] + * 0x00000008 software interrupt indirect branch to [0xfffffef4] + * 0x0000000c prefetch abort indirect branch to [0xfffffef8] + * 0x00000010 data abort indirect branch to [0xfffffefc] + * 0x00000014 (reserved in ARMv5) vector to ROM reset: 0xc0000000 + * 0x00000018 IRQ indirect branch to [0xffffff00] + * 0x0000001c FIQ indirect branch to [0xffffff04] + * + * In order to initialize exceptions on i.MX27, we must copy U-Boot's + * indirect (not exception!) vector table into 0xfffffef0..0xffffff04 + * taking care not to copy vectors number 5 (reserved exception). + */ + + .section .text.relocate_vectors,"ax",%progbits + +ENTRY(relocate_vectors) + + ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ + ldr r1, =32 /* size of vector table */ + add r0, r0, r1 /* skip to indirect table */ + ldr r1, =0xFFFFFEF0 /* i.MX27 indirect table */ + ldmia r0!, {r2-r8} /* load indirect vectors 1..7 */ + stmia r1!, {r2-r5, r7,r8} /* write all but vector 5 */ + + bx lr + +ENDPROC(relocate_vectors) diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S index 29cdad0..a33ad3e 100644 --- a/arch/arm/lib/crt0.S +++ b/arch/arm/lib/crt0.S @@ -104,6 +104,11 @@ clr_gd: ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ b relocate_code here: +/* + * now relocate vectors + */ + + bl relocate_vectors /* Set up final (full) environment */ diff --git a/arch/arm/lib/relocate.S b/arch/arm/lib/relocate.S index 6ede41c..92f5314 100644 --- a/arch/arm/lib/relocate.S +++ b/arch/arm/lib/relocate.S @@ -11,6 +11,47 @@ #include <linux/linkage.h> /* + * Default/weak exception vectors relocation routine + * + * This routine covers the standard ARM cases: normal (0x00000000), + * high (0xffff0000) and VBAR. SoCs which do not comply with any of + * the standard cases must provide their own, strong, version. + */ + + .section .text.relocate_vectors,"ax",%progbits + .weak relocate_vectors + +ENTRY(relocate_vectors) + +#ifdef CONFIG_HAS_VBAR + /* + * If the ARM processor has the security extensions, + * use VBAR to relocate the exception vectors. + */ + ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ + mcr p15, 0, r0, c12, c0, 0 /* Set VBAR */ +#else + /* + * Copy the relocated exception vectors to the + * correct address + * CP15 c1 V bit gives us the location of the vectors: + * 0x00000000 or 0xFFFF0000. + */ + ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ + mrc p15, 0, r2, c1, c0, 0 /* V bit (bit[13]) in CP15 c1 */ + ands r2, r2, #(1 << 13) + ldreq r1, =0x00000000 /* If V=0 */ + ldrne r1, =0xFFFF0000 /* If V=1 */ + ldmia r0!, {r2-r8,r10} + stmia r1!, {r2-r8,r10} + ldmia r0!, {r2-r8,r10} + stmia r1!, {r2-r8,r10} +#endif + bx lr + +ENDPROC(relocate_vectors) + +/* * void relocate_code(addr_moni) * * This function relocates the monitor code. @@ -54,34 +95,6 @@ fixnext: cmp r2, r3 blo fixloop - /* - * Relocate the exception vectors - */ -#ifdef CONFIG_HAS_VBAR - /* - * If the ARM processor has the security extensions, - * use VBAR to relocate the exception vectors. - */ - ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ - mcr p15, 0, r0, c12, c0, 0 /* Set VBAR */ -#else - /* - * Copy the relocated exception vectors to the - * correct address - * CP15 c1 V bit gives us the location of the vectors: - * 0x00000000 or 0xFFFF0000. - */ - ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ - mrc p15, 0, r2, c1, c0, 0 /* V bit (bit[13]) in CP15 c1 */ - ands r2, r2, #(1 << 13) - ldreq r1, =0x00000000 /* If V=0 */ - ldrne r1, =0xFFFF0000 /* If V=1 */ - ldmia r0!, {r2-r8,r10} - stmia r1!, {r2-r8,r10} - ldmia r0!, {r2-r8,r10} - stmia r1!, {r2-r8,r10} -#endif - relocate_done: #ifdef __XSCALE__ |