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@@ -8,18 +8,51 @@ asm(
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" .text\n"
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" .globl _start\n"
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" .type _start,%function\n"
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- "_start:\n"
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- " mov r7, sp\n"
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- " @ldr r0, [sp], #4\n"
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- " mov r0, sp\n"
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- " bl _dl_start\n"
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- " mov r6, r0\n"
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- " mov r0, r7\n"
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- " mov pc, r6\n"
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+ "_start:\n"
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+ " @ at start time, all the args are on the stack\n"
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+ " mov r0, sp\n"
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+ " bl _dl_start\n"
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+ " @ returns user entry point in r0\n"
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+ " mov r6, r0\n"
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+ " @ we are PIC code, so get global offset table\n"
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+ " ldr sl, .L_GET_GOT\n"
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+ " add sl, pc, sl\n"
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+ ".L_GOT_GOT:\n"
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+ " @ See if we were run as a command with the executable file\n"
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+ " @ name as an extra leading argument.\n"
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+ " ldr r4, .L_SKIP_ARGS\n"
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+ " ldr r4, [sl, r4]\n"
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+ " @ get the original arg count\n"
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+ " ldr r1, [sp]\n"
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+ " @ subtract _dl_skip_args from it\n"
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+ " sub r1, r1, r4\n"
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+ " @ adjust the stack pointer to skip them\n"
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+ " add sp, sp, r4, lsl #2\n"
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+ " @ get the argv address\n"
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+ " add r2, sp, #4\n"
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+ " @ store the new argc in the new stack location\n"
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+ " str r1, [sp]\n"
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+ " @ compute envp\n"
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+ " add r3, r2, r1, lsl #2\n"
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+ " add r3, r3, #4\n"
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+ "\n\n"
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+ " @ load the finalizer function\n"
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+ " ldr r0, .L_FINI_PROC\n"
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+ " ldr r0, [sl, r0]\n"
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+ " @ jump to the user_s entry point\n"
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+ " mov pc, r6\n"
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+ ".L_GET_GOT:\n"
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+ " .word _GLOBAL_OFFSET_TABLE_ - .L_GOT_GOT - 4\n"
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+ ".L_SKIP_ARGS:\n"
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+ " .word _dl_skip_args(GOTOFF)\n"
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+ ".L_FINI_PROC:\n"
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+ " .word _dl_fini(GOT)\n"
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+ "\n\n"
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" .size _start,.-_start\n"
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- " .previous\n"
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+ ".previous\n"
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);
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+
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/* Get a pointer to the argv array. On many platforms this can be just
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* the address if the first argument, on other platforms we need to
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* do something a little more subtle here. */
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Eric Andersen