diff options
author | Corinna Vinschen <corinna@vinschen.de> | 2013-06-25 16:06:15 +0400 |
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committer | Corinna Vinschen <corinna@vinschen.de> | 2013-06-25 16:06:15 +0400 |
commit | 15b1ed6dc78615f26859146aa764a412b87cee8c (patch) | |
tree | 9e4fcc76b73ce964ce5652465328eba6920553f3 /libgloss/aarch64/crt0.S | |
parent | c024ce1422a60f9600b922f081be3ada47a489ae (diff) |
* aarch64/crt0.S (GEN_DWORD): New macro definition.
(PTR_REG): Ditto.
(PTR_SIZE): Ditto.
(PTR_LOG_SIZE): Ditto.
(start): Use GEN_DWORD to replace the .dword of HeapBase,
__bss_start__, __bss_end__, FUNCTION(_fini), env and
CommandLine; when __ILP32__ is defined, set the stack base to
the top end of the 32-bit address space if the returned value
from the Angel API call is larger than or equal to 4 GiB.
Also carry out sanity check on the heap base; abort if the
base is larger than or equal to 4 GiB. Use other new
macros in the instructions that processes the argv arrays.
(StackBase): New lable; replace __stack_base__.
(__stack_base__): Set with StackBase or StackBase + 4.
Diffstat (limited to 'libgloss/aarch64/crt0.S')
-rw-r--r-- | libgloss/aarch64/crt0.S | 92 |
1 files changed, 75 insertions, 17 deletions
diff --git a/libgloss/aarch64/crt0.S b/libgloss/aarch64/crt0.S index 601bb2bb1..1a5cabbb3 100644 --- a/libgloss/aarch64/crt0.S +++ b/libgloss/aarch64/crt0.S @@ -41,6 +41,36 @@ #define _fini __libc_fini_array #endif +/* In ELF64, the large addressing model is used and R_AARCH64_ABS64 + reloc is generated to relocate a 64-bit address. Since 64-bit + relocation is not available in ELF32, in order to have + a single code path for both ELF64 and ELF32 classes, we synthesize + a 64-bit relocation by using R_AARCH64_P32_ABS32 on one of the two + .word directives, depending on the endianness. */ + +.macro GEN_DWORD name +#if defined(__ILP32__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + .word \name + .word 0 +#elif defined(__ILP32__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + .word 0 + .word \name +#else + .dword \name +#endif +.endm + +/* Help tackle the pointer size difference between ELF64 and ELF32. */ +#ifdef __ILP32__ +#define PTR_REG(n) w##n +#define PTR_SIZE 4 +#define PTR_LOG_SIZE 2 +#else +#define PTR_REG(n) x##n +#define PTR_SIZE 8 +#define PTR_LOG_SIZE 3 +#endif + .text .macro FUNC_START name .global \name @@ -71,10 +101,33 @@ command line options to the AEM in order to define the values exposed here in the HeapInfo Angel call. */ ldr x0, .LC0 /* point at returned values */ - ldr x0, [x0, #8] /* get heap_limit */ + ldr x1, [x0, #8] /* get heap_limit */ +#ifdef __ILP32__ + /* Sanity check on the heap base. */ + ldr x0, [x0] /* get heap_base */ + tst x0, #0xffffffff00000000 + beq 1f + /* Exit with 1 if the heap base is not within the 32-bit address + space. */ + mov x0, ADP_Stopped_ApplicationExit & 0xff + movk x0, ADP_Stopped_ApplicationExit >> 16, lsl #16 + adrp x1, HeapBase /* Reuse to construct the parameter block. */ + add x1, x1, #:lo12:HeapBase + str x0, [x1] + mov x0, 1 + str x0, [x1, #8] + mov w0, #AngelSVC_Reason_ReportException + AngelSVCAsm AngelSVC +1: + /* For the sake of safety, set the stack base to the top end of + the 32-bit address space if the returned value from the + Angel API call is larger than or equal to 4 GiB. */ + tst x1, #0xffffffff00000000 + csinv w1, w1, wzr, eq +#endif /* Ensure quad-word stack alignment. */ - and x0, x0, #~15 + and x0, x1, #~15 mov sp, x0 /* Setup an initial dummy frame with saved fp=0 and saved lr=0 */ @@ -114,7 +167,7 @@ ldr x2, .Lenvp /* envp */ /* Put NULL at end of argv array. */ - str x0, [x1, #-8]! + str PTR_REG (0), [x1, #-PTR_SIZE]! /* Skip leading blanks. */ .Lnext: ldrb w3, [x8], #1 @@ -133,7 +186,7 @@ cinc x8, x8, eq /* Push arg pointer to argv, and bump argc. */ - str x8, [x1, #-8]! + str PTR_REG (8), [x1, #-PTR_SIZE]! add x0, x0, #1 /* Find end of arg string. */ @@ -149,14 +202,14 @@ /* Reverse argv array. */ .Lendstr: - add x3, x1, #0 /* sp = &argv[0] */ - add x4, x1, w0, uxtw #3 /* ep = &argv[argc] */ + add x3, x1, #0 /* sp = &argv[0] */ + add x4, x1, w0, uxtw #PTR_LOG_SIZE /* ep = &argv[argc] */ cmp x4, x3 b.lo 2f -1: ldr x5, [x4, #-8] /* x5 = ep[-1] */ - ldr x6, [x3] /* x6 = *sp */ - str x6, [x4, #-8]! /* *--ep = x6 */ - str x5, [x3], #8 /* *sp++ = x5 */ +1: ldr PTR_REG (5), [x4, #-PTR_SIZE] /* PTR_REG (5) = ep[-1] */ + ldr PTR_REG (6), [x3] /* PTR_REG (6) = *sp */ + str PTR_REG (6), [x4, #-PTR_SIZE]! /* *--ep = PTR_REG (6) */ + str PTR_REG (5), [x3], #PTR_SIZE /* *sp++ = PTR_REG (5) */ cmp x4, x3 b.hi 1b 2: @@ -177,27 +230,32 @@ FUNCTION (_cpu_init_hook): .align 3 .LC0: - .dword HeapBase + GEN_DWORD HeapBase .LC1: - .dword __bss_start__ + GEN_DWORD __bss_start__ .LC2: - .dword __bss_end__ + GEN_DWORD __bss_end__ .Lfini: - .dword FUNCTION(_fini) + GEN_DWORD FUNCTION(_fini) .Lenvp: - .dword env + GEN_DWORD env .Lcmdline: - .dword CommandLine + GEN_DWORD CommandLine .dword 255 /* Workspace for Angel calls. */ .data .align 3 /* Data returned by monitor SVC. */ +#if defined(__ILP32__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + .set __stack_base__, StackBase + 4 +#else + .set __stack_base__, StackBase +#endif .global __stack_base__ HeapBase: .dword 0 HeapLimit: .dword 0 -__stack_base__: .dword 0 +StackBase: .dword 0 StackLimit: .dword 0 env: .dword 0 /* Dummy environment array */ CommandLine: .space 256,0 /* Maximum length of 255 chars handled. */ |