Is this a normal output ? What flags do I need ?

Jon Zarate

I compiled a project with CCS. The code is this:

int main(void) {
    WDTCTL = WDTPW | WDTHOLD;	// Stop watchdog timer

    P1DIR |= BIT0;

    P2DIR &= ~BIT1;
    P2OUT |= BIT1;
    P2REN |= BIT1;

    while (1){

    	if ((P2IN & BIT1) == 0){
    		red_on();
    	}else{
    		red_off();
    	}

    }

	return 0;
}

void red_on(){
	P1OUT |= BIT0;
}

void red_off(){
	P1OUT &= 0xFE;
}

The output is 70 MB. It contains 401 sections. This output was made by a program I wrote because the linux terminal tools don't show them all, just 255.

-1a84591e31034fac832d29ed8584666c584403515_code-editor-fs">Fullscreen /e2e.ti.com/cfs-filesystemfile/__key/communityserver-discussions-components-files/81/elf_5F00_output.txt?_=636742536600000000" elf_output.txt">elf_output.txt /e2e.ti.com/cfs-filesystemfile/__key/communityserver-discussions-components-files/81/elf_5F00_output.txt?_=636742536600000000" elf_output.txt">Download 4591e31034fac832d29ed8584666c584403515_code-editor" 2px;min-width:1230px;margin:0px;" ELF HEADER --------------- [ELF] [1] (32 bits) [1] (little endian) [1] [0] [0] [] [1] (relocatable) [69 (hex)][105 (dec)] [1] [0x0] [0xdbbc] [0xdbbc] [0] [52] [32] [0] [40] [402] string section header: [401] ELF HEADER --------------- ELF PROGRAM HEADER --------------- ELF PROGRAM HEADER --------------- ELF SECTION HEADER (402) --------------- Size VMA LMA File off Algn EntSize Info Type Flags 0 0 0 0 0 0 0 0 0 0 0 34 0 4 1352 17 0 0 0 4c 0 4 1398 17 0 0 0 64 0 4 1400 17 0 0 0 7c 0 4 1401 17 0 0 0 0 94 1 0 0 8 3 16 2400 2400 94 2 0 0 1 3 0 0 0 1 0 0 8 268435456 0 0 0 0 1 0 0 8 0 4 43fc 43fc a4 2 0 0 8 3 4400 4400 a4 2 0 0 1 6 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 c4 1 0 0 8 3 0 0 c4 1 0 0 8 2 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 0 0 0 0 1 0 0 8 0 2 ffd2 ffd2 c4 1 0 0 1 2 2 ffd4 ffd4 c6 1 0 0 1 2 ffd6 ffd6 c8 1 0 0 1 2 ffd8 ffd8 ca 1 0 0 1 2 2 ffda ffda cc 1 0 0 1 2 2 ffdc ffdc ce 1 0 0 1 2 2 ffde ffde d0 1 0 0 1 2 ffe0 ffe0 d2 1 0 0 1 2 ffe2 ffe2 d4 1 0 0 1 2 2 ffe4 ffe4 d6 1 0 0 1 2 2 ffe6 ffe6 d8 1 0 0 1 2 ffe8 ffe8 da 1 0 0 1 2 ffea ffea dc 1 0 0 1 2 2 ffec ffec de 1 0 0 1 2 2 ffee ffee e0 1 0 0 1 2 2 fff0 fff0 e2 1 0 0 1 2 2 fff2 fff2 e4 1 0 0 1 2 fff4 fff4 e6 1 0 0 1 2 fff6 fff6 e8 1 0 0 1 2 2 fff8 fff8 ea 1 0 0 1 2 2 fffa fffa ec 1 0 0 1 2 2 fffc fffc ee 1 0 0 1 2 2 fffe fffe f0 2 0 0 1 2 2400 2400 f2 1 0 0 8 268435458 0 0 f2 1 0 0 1 0 0 0 1fc 1 0 0 1 0 0 0 2f1 1 0 0 1 0 0 0 3e8 1 0 0 1 512 0 0 46c 1 0 0 1 0 0 0 4b6 1 0 0 1 0 0 0 4f6 1 0 0 1 0 0 0 536 1 0 0 1 512 0 0 556 1 0 0 1 0 0 0 59d 1 0 0 1 0 0 0 5e4 1 0 0 1 0 0 0 62b 1 0 0 1 0 0 0 67f 1 0 0 1 0 0 0 6cf 1 0 0 1 0 0 0 71f 1 0 0 1 512 247 0 0 73e 1 0 0 1 512 0 0 835 1 0 0 1 0 0 0 855 1 0 0 1 0 0 0 875 1 0 0 1 0 0 0 895 1 0 0 1 0 0 0 8b0 1 0 0 1 0 0 0 8cd 1 0 0 1 0 0 0 8eb 1 0 0 1 512 0 0 9d8 1 0 0 1 0 0 0 aae 1 0 0 1 0 0 0 bf6 1 0 0 1 0 0 0 c20 1 0 0 1 0 0 0 c64 1 0 0 1 0 0 0 ca6 1 0 0 1 0 0 0 ccf 1 0 0 1 0 0 0 d27 1 0 0 1 0 0 0 d47 1 0 0 1 0 0 0 d64 1 0 0 1 0 0 0 d83 1 0 0 1 0 0 0 f5e 1 0 0 1 0 0 0 1056 1 0 0 1 0 0 0 11a9 1 0 0 1 0 0 0 1232 1 0 0 1 0 0 0 126c 1 0 0 1 0 0 0 12b6 1 0 0 1 0 0 0 12fd 1 0 0 1 0 0 0 134d 1 0 0 1 0 0 0 13b1 1 0 0 1 0 0 0 13f6 1 0 0 1 0 0 0 1482 1 0 0 1 0 0 0 14a2 1 0 0 1 0 0 0 14c2 1 0 0 1 0 0 0 14de 1 0 0 1 0 0 0 14f9 1 0 0 1 0 0 0 15d2 1 0 0 1 0 0 0 16c2 1 0 0 1 0 0 0 17ae 1 0 0 1 0 0 0 17ce 1 0 0 1 0 0 0 17fe 1 0 0 1 0 0 0 182e 1 0 0 1 0 0 0 1861 1 0 0 1 0 0 0 188a 1 0 0 1 0 0 0 18b3 1 0 0 1 0 0 0 18da 1 0 0 1 0 0 0 18ff 1 0 0 1 0 0 0 19eb 1 0 0 1 0 0 0 1a27 1 0 0 1 0 0 0 1a4f 1 0 0 1 0 0 0 1a6f 1 0 0 1 0 0 0 1a9a 1 0 0 1 0 0 0 1bab 1 0 0 1 0 0 0 1cbc 1 0 0 1 0 0 0 1d04 1 0 0 1 0 0 0 1d4f 1 0 0 1 0 0 0 1d8b 1 0 0 1 0 0 0 1dc7 1 0 0 1 0 0 0 1de7 1 0 0 1 0 0 0 1e07 1 0 0 1 0 0 0 1e31 1 0 0 1 0 0 0 1e5b 1 0 0 1 0 0 0 1f68 1 0 0 1 0 0 0 1fad 1 0 0 1 0 0 0 1fe9 1 0 0 1 0 0 0 2009 1 0 0 1 0 0 0 2032 1 0 0 1 0 0 0 2145 1 0 0 1 0 0 0 2258 1 0 0 1 0 0 0 22a7 1 0 0 1 0 0 0 22f6 1 0 0 1 0 0 0 2332 1 0 0 1 0 0 0 236e 1 0 0 1 0 0 0 238e 1 0 0 1 0 0 0 23ae 1 0 0 1 0 0 0 23d9 1 0 0 1 0 0 0 2404 1 0 0 1 0 0 0 2511 1 0 0 1 0 0 0 2559 1 0 0 1 0 0 0 2595 1 0 0 1 0 0 0 25b5 1 0 0 1 0 0 0 25de 1 0 0 1 0 0 0 26ed 1 0 0 1 0 0 0 2746 1 0 0 1 0 0 0 2782 1 0 0 1 0 0 0 27a2 1 0 0 1 0 0 0 27cc 1 0 0 1 0 0 0 28f5 1 0 0 1 0 0 0 2933 1 0 0 1 0 0 0 297a 1 0 0 1 0 0 0 29cf 1 0 0 1 0 0 0 29ef 1 0 0 1 0 0 0 2a16 1 0 0 1 0 0 0 2b54 1 0 0 1 0 0 0 2c29 1 0 0 1 0 0 0 2d02 1 0 0 1 0 0 0 2e48 1 0 0 1 0 0 0 2f82 1 0 0 1 0 0 0 3086 1 0 0 1 0 0 0 30a6 1 0 0 1 0 0 0 30d1 1 0 0 1 0 0 0 30fc 1 0 0 1 0 0 0 3137 1 0 0 1 0 0 0 3172 1 0 0 1 0 0 0 31aa 1 0 0 1 0 0 0 31f1 1 0 0 1 0 0 0 3238 1 0 0 1 0 0 0 327f 1 0 0 1 0 0 0 32bd 1 0 0 1 0 0 0 32e6 1 0 0 1 0 0 0 330f 1 0 0 1 0 0 0 337e 1 0 0 1 0 0 0 33ed 1 0 0 1 0 0 0 3440 1 0 0 1 0 0 0 3460 1 0 0 1 0 0 0 3480 1 0 0 1 0 0 0 34a0 1 0 0 1 0 0 0 34bc 1 0 0 1 0 0 0 34da 1 0 0 1 0 0 0 3501 1 0 0 1 0 0 0 3526 1 0 0 1 0 0 0 3541 1 0 0 1 0 0 0 36ff 1 0 0 1 0 0 0 3847 1 0 0 1 512 0 0 38a5 1 0 0 1 0 0 0 38d0 1 0 0 1 0 0 0 3921 1 0 0 1 512 0 0 394c 1 0 0 1 0 0 0 3993 1 0 0 1 0 0 0 3a35 1 0 0 1 0 0 0 3a9d 1 0 0 1 512 183 0 0 3ae6 1 0 0 1 512 0 0 3b9d 1 0 0 1 0 0 0 3bbd 1 0 0 1 0 0 0 3bde 1 0 0 1 512 0 0 3bf9 1 0 0 1 0 0 0 3efd 1 0 0 1 0 0 0 40d5 1 0 0 1 512 0 0 410e 1 0 0 1 512 0 0 413a 1 0 0 1 0 0 0 417a 1 0 0 1 0 0 0 420e 1 0 0 1 512 0 0 423c 1 0 0 1 512 0 0 42bc 1 0 0 1 0 0 0 4312 1 0 0 1 0 0 0 439f 1 0 0 1 0 0 0 440f 1 0 0 1 512 195 0 0 4433 1 0 0 1 512 0 0 44f6 1 0 0 1 512 262 0 0 451a 1 0 0 1 512 0 0 4620 1 0 0 1 0 0 0 4640 1 0 0 1 0 0 0 466a 1 0 0 1 512 0 0 469c 1 0 0 1 512 550 10000 10000 46bc 2 0 0 1 6 0 0 48e2 0 0 0 1879048195 0 22560 0 0 4968 0 16 601 2 0 0 0 a188 1 8 0 1879048193 130 264 0 0 a188 0 8 253 9 0 0 0 a290 0 8 86 9 0 0 0 a2d8 0 8 87 9 0 0 0 a310 0 8 88 9 0 0 0 a348 0 8 89 9 0 0 0 a3e0 0 8 90 9 0 0 0 a3e8 0 8 91 9 0 0 0 a3f0 0 8 92 9 0 0 0 a3f8 0 8 94 9 0 0 0 a408 0 8 95 9 0 0 0 a418 0 8 96 9 0 0 0 a428 0 8 102 9 0 0 0 a438 0 8 103 9 0 0 0 a448 0 8 104 9 0 0 0 a458 0 8 105 9 0 0 0 a460 0 8 106 9 0 0 0 a468 0 8 107 9 0 0 0 a470 0 8 108 9 0 0 0 a478 0 8 10 9 0 0 0 a4a0 0 8 84 9 0 0 0 a4a8 0 8 109 9 0 0 0 a4c8 0 8 110 9 0 0 0 a518 0 8 112 9 0 0 0 a520 0 8 113 9 0 0 0 a530 0 8 116 9 0 0 0 a540 0 8 117 9 0 0 0 a548 0 8 118 9 0 0 0 a550 0 8 119 9 0 0 0 a570 0 8 120 9 0 0 0 a5a0 0 8 121 9 0 0 0 a610 0 8 123 9 0 0 0 a618 0 8 124 9 0 0 0 a620 0 8 125 9 0 0 0 a630 0 8 126 9 0 0 0 a640 0 8 130 9 0 0 0 a650 0 8 131 9 0 0 0 a660 0 8 132 9 0 0 0 a668 0 8 133 9 0 0 0 a670 0 8 134 9 0 0 0 a688 0 8 135 9 0 0 0 a6a8 0 8 136 9 0 0 0 a6c8 0 8 143 9 0 0 0 a6d0 0 8 144 9 0 8 0 0 a6d8 0 8 62 9 0 0 0 a6e0 0 8 63 9 0 0 0 a6e8 0 8 64 9 0 0 0 a6f0 0 8 65 9 0 0 0 a6f8 0 8 66 9 0 0 0 a700 0 8 67 9 0 0 0 a708 0 8 68 9 0 0 0 a710 0 8 69 9 0 0 0 a718 0 8 70 9 0 8 0 0 a720 0 8 71 9 0 0 0 a728 0 8 72 9 0 0 0 a730 0 8 73 9 0 0 0 a738 0 8 74 9 0 0 0 a740 0 8 75 9 0 0 0 a748 0 8 76 9 0 0 0 a750 0 8 77 9 0 8 0 0 a758 0 8 78 9 0 0 0 a760 0 8 79 9 0 0 0 a768 0 8 80 9 0 0 0 a770 0 8 81 9 0 8 0 0 a778 0 8 82 9 0 0 0 a780 0 8 83 9 0 0 0 a788 0 8 145 9 0 0 0 a7b8 0 8 146 9 0 0 0 a7c0 0 8 148 9 0 0 0 a7d0 0 8 149 9 0 0 0 a7d8 0 8 150 9 0 0 0 a810 0 8 151 9 0 0 0 a848 0 8 152 9 0 0 0 a850 0 8 153 9 0 0 0 a858 0 8 156 9 0 0 0 a868 0 8 157 9 0 0 0 a878 0 8 158 9 0 0 0 a880 0 8 159 9 0 0 0 a888 0 8 160 9 0 0 0 a8c0 0 8 161 9 0 0 0 a8c8 0 8 163 9 0 0 0 a8d8 0 8 164 9 0 0 0 a8e0 0 8 165 9 0 0 0 a918 0 8 166 9 0 0 0 a950 0 8 167 9 0 0 0 a958 0 8 168 9 0 0 0 a960 0 8 171 9 0 0 0 a970 0 8 172 9 0 0 0 a980 0 8 173 9 0 0 0 a988 0 8 174 9 0 0 0 a990 0 8 175 9 0 0 0 a9c8 0 8 176 9 0 0 0 a9d0 0 8 178 9 0 0 0 a9e0 0 8 179 9 0 0 0 a9e8 0 8 180 9 0 0 0 aa20 0 8 181 9 0 0 0 aa28 0 8 183 9 0 0 0 aa38 0 8 184 9 0 0 0 aa40 0 8 185 9 0 0 0 aa80 0 8 186 9 0 0 0 aa88 0 8 187 9 0 0 0 aa98 0 8 189 9 0 0 0 aaa8 0 8 190 9 0 16 0 0 aab0 0 8 6 9 0 0 0 aac0 0 8 191 9 0 0 0 aad0 0 8 192 9 0 0 0 aaf0 0 8 193 9 0 0 0 ab10 0 8 194 9 0 0 0 ab58 0 8 195 9 0 0 0 aba0 0 8 196 9 0 0 0 abd8 0 8 200 9 0 0 0 abe0 0 8 201 9 0 0 0 abe8 0 8 202 9 0 0 0 abf0 0 8 203 9 0 0 0 ac00 0 8 204 9 0 0 0 ac10 0 8 205 9 0 0 0 ac20 0 8 212 9 0 0 0 ac30 0 8 213 9 0 0 0 ac40 0 8 214 9 0 0 0 ac50 0 8 215 9 0 0 0 ac58 0 8 216 9 0 0 0 ac60 0 8 217 9 0 0 0 ac68 0 8 218 9 0 0 0 ac70 0 8 219 9 0 0 0 ac78 0 12 253 4 0 0 0 ac84 0 8 220 9 0 0 0 acc4 0 8 221 9 0 0 0 ad14 0 8 222 9 0 0 0 ad74 0 8 224 9 0 0 0 ad7c 0 8 226 9 0 0 0 ad8c 0 8 231 9 0 0 0 ad9c 0 8 232 9 0 0 0 ada4 0 8 233 9 0 0 0 adac 0 8 234 9 0 0 0 ade4 0 8 235 9 0 0 0 ae54 0 8 236 9 0 0 0 ae9c 0 8 237 9 0 0 0 aed4 0 8 239 9 0 0 0 aedc 0 8 242 9 0 0 0 aeec 0 8 249 9 0 0 0 aefc 0 8 250 9 0 0 0 af04 0 8 251 9 0 0 0 af0c 0 8 252 9 0 0 0 af14 0 0 0 2130706437 0 9933 0 0 af2e 0 1 0 3 32 1472 0 0 d5fb 0 1 0 3 32 ELF SECTION HEADER --------------- = j('#fragment-1a84591e31034fac832d29ed8584666c584403515_code-editor-fs'); = j('#fragment-1a84591e31034fac832d29ed8584666c584403515_code-editor'); function(){ volutionCodeEditor('fullscreen')) { volutionCodeEditor('fullscreen', false); volutionCodeEditor('fullscreen', true);

Last question, I am creating a software that performs the relocations in-time reading the ELF file from the flash memory. I was told not to use section names to perform the set up of the program, so I am trying to use flags and types. I would like to know what sections must be copied so that I can check what type and flags they use and ensure that other sections don't have the same.

Thank you.

EDIT: I realised that .text:_isr and .text have the same type and flags, however, I don't need the .text:_isr right ? Isn't that for initialization ? How can I know which one is the .text without checking names ?

Apart from that, this is the output if I filter the sections by flags. Only the ones containing flag = 3 or 6 are shown.

 Idx  Name             Size      VMA       LMA       File off  Algn  EntSize   Info Type     Flags
  5.  .bss             0         0         0         94        1     0         0    8        3       
  6.  .data            16        2400      2400      94        2     0         0    1        3       
  9.  .stack           4         43fc      43fc      a4        2     0         0    8        3       
 10.  .text:_isr       32        4400      4400      a4        2     0         0    1        6       
 15.  .init_array      0         0         0         c4        1     0         0    8        3       
253.  .text            550       10000     10000     46bc      2     0         0    1        6

If I add a type filter I could discard .init_array and I would have a list of all needed sections. Is there any important section missing ?

To filter all the relocation sections I will check that the section referenced in the "info" attribute has flags 6. However, I still have the problem of differentiating the .text:_isr and .text.

over 9 years ago

George Mock over 9 years ago

TI__Guru**** 250380 points

I cannot reproduce this result. Please send in your project. With that project active, select File | Export. In the dialog that pops up, expand General then choose Archive File. The rest of it is straightforward. Attach the .zip file to your next post.

Thanks and regards,

-George

Jon Zarate over 9 years ago in reply to George Mock

Expert 1190 points

Here it is. In previous versions I used the Red Hat compiler so there are a lot of folders, plus, I forgot to mention that the project is supposed to generate a relocatable file, so please don't forget to answer the questions in the bottom of the first post if you know the answer.

Thank you.

ButtonLed.zip

Archaeologist over 9 years ago

TI__Guru* 84285 points

Yes, that look about right in terms of number of sections. The vast majority of sections are debugging info and relocations, neither of which get allocated to target memory.

As I noted in the other thread, you must load every section which has section type SHT_PROGBITS and section flag SHF_ALLOC. More precisely, you must allocate space for every section that is SHF_ALLOC, and you must copy the initial value of each section which has type SHT_PROGBITS. This includes .init_array, although you could probably get away with not loading .init_array because it has zero size.

Judging by its name, .text:_isr probably contains the interrupt service routines. For an arbitrary program, you can't just leave out this section; if it has interrupt service routines, it probably needs them to function correctly.

If the boot routine does not do what you want, you need to recompile the ELF executable with a boot routine that is more suitable to your system. The default boot routine provided in the TI RTS (and most custom boot routines for other projects) assume bare metal mode, and your system is clearly not bare metal. I understand that in a system like Linux, you don't start every program with a bare metal boot routine, but that's because you link every Linux program with a Linux-specific boot routine which understands that is running under Linux.

You might be able to get away without a special boot routine if the programs you are trying to load are particularly well-behaved, but what you're really trying to do is make a simple operating system, and making this work in the general case is quite complicated. Other TI compilers provide features (e.g. PIC, dynamic linking) to facilitate concurrent programs, but the TI MSP compiler just doesn't provide these features.

Jon Zarate over 9 years ago in reply to Archaeologist

Expert 1190 points

I filtered by SHF_ALLOC as you said and this is the output:

Idx  Name             Size      VMA       LMA       File off  Algn  EntSize   Info Type     Flags
  5.  .bss             0         0         0         94        1     0         0    8        3       
  6.  .data            16        2400      2400      94        2     0         0    1        3       
  9.  .stack           4         43fc      43fc      a4        2     0         0    8        3       
 10.  .text:_isr       32        4400      4400      a4        2     0         0    1        6       
 15.  .init_array      0         0         0         c4        1     0         0    8        3       
 16.  .mspabi.extab    0         0         0         c4        1     0         0    8        2       
 62.  RTC              2         ffd2      ffd2      c4        1     0         0    1        2       
 63.  PORT2            2         ffd4      ffd4      c6        1     0         0    1        2       
 64.  TIMER2_A1        2         ffd6      ffd6      c8        1     0         0    1        2       
 65.  TIMER2_A0        2         ffd8      ffd8      ca        1     0         0    1        2       
 66.  USCI_B1          2         ffda      ffda      cc        1     0         0    1        2       
 67.  USCI_A1          2         ffdc      ffdc      ce        1     0         0    1        2       
 68.  PORT1            2         ffde      ffde      d0        1     0         0    1        2       
 69.  TIMER1_A1        2         ffe0      ffe0      d2        1     0         0    1        2       
 70.  TIMER1_A0        2         ffe2      ffe2      d4        1     0         0    1        2       
 71.  DMA              2         ffe4      ffe4      d6        1     0         0    1        2       
 72.  USB_UBM          2         ffe6      ffe6      d8        1     0         0    1        2       
 73.  TIMER0_A1        2         ffe8      ffe8      da        1     0         0    1        2       
 74.  TIMER0_A0        2         ffea      ffea      dc        1     0         0    1        2       
 75.  ADC12            2         ffec      ffec      de        1     0         0    1        2       
 76.  USCI_B0          2         ffee      ffee      e0        1     0         0    1        2       
 77.  USCI_A0          2         fff0      fff0      e2        1     0         0    1        2       
 78.  WDT              2         fff2      fff2      e4        1     0         0    1        2       
 79.  TIMER0_B1        2         fff4      fff4      e6        1     0         0    1        2       
 80.  TIMER0_B0        2         fff6      fff6      e8        1     0         0    1        2       
 81.  COMP_B           2         fff8      fff8      ea        1     0         0    1        2       
 82.  UNMI             2         fffa      fffa      ec        1     0         0    1        2       
 83.  SYSNMI           2         fffc      fffc      ee        1     0         0    1        2       
 84.  .reset           2         fffe      fffe      f0        2     0         0    1        2       
 85.  .TI.persistent   0         2400      2400      f2        1     0         0    8        268435458
253.  .text            550       10000     10000     46bc      2     0         0    1        6       
256.  .mspabi.exidx    0         0         0         a188      1     8         0    1879048193 130

As we see, there are a lot of sections here, if we also add the SHT_PROGBITS to the filter, there are still a lot of them, mostly peripheral registers. (1) Any idea how to avoid initializing these ? Checking for size == 0 doesn't work here.

Regarding .text:_isr, if the program doesn't have interrupts, (2) could this be ignored ?

I don't understand the concepts boot routine and bare metal mode. (3) Is the boot routine in .text:_isr ? (4) Can I change the boot of a program so that it's empty ? That would make the relocation easier since the board doesn't need to be initialized for every new program loaded.

I also wanted to point out that I am not developing the OS, however, I have to consider that an OS in the future will load several ELF files so I have to take into account that they may overlap (like initializing Timer registers etc.).

Thank you.

Archaeologist over 9 years ago in reply to Jon Zarate

TI__Guru* 84285 points

I'm pretty sure those small sections are all slots in the interrupt vector. Note the addresses are all between ffd2 and fffe. They are in fact supposed to be loaded. Per your claim your program does not have interrupts, you could omit these. The only way to tell them apart from the other sections would be by name or address. However, I still recommend that you instead change your linker command file such that you don't have them in the first place.

Looking at ButtonLED/Debug/ButtonLED.out from an earlier post, it appears that .text:_isr contains only the boot routine. The boot routine is responsible for setting things like the stack pointer, so you really need it. Otherwise, your loader needs to set the stack pointer properly. Please read chapter 2 chapter 3 "Program Loading and Running" of the latest MSP430 Assembly Language Tools User's Guide, which fully defines and describes the boot routine:
software-dl.ti.com/.../

I understand that you are not developing the whole OS, but you are developing a part of an OS and you need to be very familiar with how the loaded programs and the loader will co-exist.

Roughly speaking "bare metal" means there is only one program is running on the chip, and no OS. This program controls everything.

Yes, you can change the boot routine however much you want. I just don't recommend altering the program at load time.

Jon Zarate over 9 years ago in reply to Archaeologist

Expert 1190 points

EDIT : After talking to my boss, I was told that the program must work with all types of resources like interrupts, timers... We will just assume the programmer is aware of this and won't use the same resources in several programs, so that they don' overlap. (5) Could you tell me what do I have to take care of in order to achieve this ? I can't load all those sections from ffd2 to fffe because they may erase the previous settings. (6) Would my (3) take care of that by removing it ?

Archaeologist said:
I'm pretty sure those small sections are all slots in the interrupt vector

(1) I don't understand, slots ?

Archaeologist said:
They are in fact supposed to be loaded

But once the Loader is started, I don't have to load them again for every ELF I want to load, (2) right ? I so, I could just take it out from the linker script, (3) right ?

Archaeologist said:
It appears that .text:_isr contains only the boot routine. The boot routine is responsible for setting things like the stack pointer, so you really need it

Okey, just to make sure I got it, I will post here all I think the initialization code is.

#pragma CLINK(_c_int00_noargs_noexit)
CSTART_DECL _c_int00_noargs_noexit()
{
   STACK_INIT();
   if (_system_pre_init() != 0) _auto_init(); // Actually this functions calls the one below, IDK how.
   main(0);
   abort();
}

void AUTO_INIT_HOLD_WDT(void)
{
    run_binit();

    uint16_t initial_WDT = WDTCTL;
    WDTCTL = HOLD_WDT;

    run_cinit();

    WDTCTL = RESTORE_WDT(initial_WDT);

    run_pinit();
}

I asked about ignoring .text:_isr because I think I don't need to execute this for every program I load, (4) do I ?

Archaeologist said:
chapter 2 "Program Loading and Running"

That title is for chapter 3, so I read that one.

Archaeologist over 9 years ago in reply to Jon Zarate

TI__Guru* 84285 points

The interrupt vector table is an array of pointers to interrupt handler functions. Each element ("slot") in the array/table contains the handler for a specific interrupt.

Jon Zarate said:
the program must work with all types of resources like interrupts, timers... We will just assume the programmer is aware of this and won't use the same resources in several programs, so that they don' overlap.

Then you are defining an API. You are setting requirements that any programmer who wants to use your loader must follow. That is, they must compile their programs in a certain way, with either no boot routine or a boot routine which is compatible with your loader. Additionally, you need some way to coordinate between programs as to which interrupts each will manage; perhaps the program would only contain interrupt vector slots for those interrupts it will handle. Given that programmers will need to do this, you probably should not further alter the program in the boot loader, so your loader should not be trying to make the decision as to whether to leave out the boot routine or interrupt vector table entries.

We've gone pretty far with these discussions, I feel I must mention... You're trying to develop a tool well beyond what TI officially supports, and I can't afford to spend this much time helping you with it. You're dealing with multiple complicated topics. Your project's scope is probably a lot bigger than you anticipate, and the requirements are a bit vague. You might want to take a step back and seriously consider whether what you are developing is the right way to solve the overarching issue. There are other strategies for having multiple tasks in a system, including multithreading or SYS/BIOS, and there are compiler features that could be added to the MSP compiler to make things easier, such as PIC or dynamic linking. I'm also skeptical that your production system will be able to afford the space to store multiple ELF object files in target memory.

Jon Zarate over 9 years ago in reply to Archaeologist

Expert 1190 points

I eventually realised what the slots were due to the names. Are they used to store the value (address of the function) to jump to in case the interrupt is raised ? You mentioned a handler, I guess it's the code that takes care of changing the PC before and after the interrupt, (1) does it do anything else ?

I think it's still not decided how the programmer will approach the problem as I am in the first versions yet, but looks like a good solution. Maybe developing a C program that prepares the ELF file would make it fast and easy to achieve.

Regarding the project: I understand what you're saying. Believe me when I say that I felt the solution was really complex since day 0. Unfortunately, I am a student working on his final degree project and I was told what to do, I did not take part in the solution, I am just researching how to do it. and the fact I never really worked with micro controllers is helping neither That's why I am really grateful for your continuous support.

I asked about PIC, and looks like it's not good from a security point of view. I read that dynamic linking works with shared libraries so I don't really understand how that could help me since I am not using any (2).

The RAM problem. It seems that they only need to have a couple of programs running and they plan to buy extra ram space.

I wanted to add that the goal is related to security. I mean, the whole idea is to add ASLR.

I will try to keep the questions short and straightforward, but this forum is my only help resource so depending on my issue I may not always succeed. if you can't afford to help just don't do it. I am aware of the complexity of the project, but there is nothing I can do about it.

Archaeologist over 9 years ago in reply to Jon Zarate

TI__Guru* 84285 points

For MSP430 yes, the slots hold a pointer to the interrupt handler, which is a function. One of those handlers is the RESET handler, which is typically the boot routine, so that when the device is RESET, it starts the program again. On interrupt, the MSP CPU handles pushing the return address to the stack and adjusting the PC. See section 1.3.4 "Interrupt Processing" in the MSP430x5xx/MSP430x6xx Family User's Guide SLAU208.

I'm relieved to hear that this is a research project, that means you don't really have to make it robust for every single contingency, which would be a lot of work. However, it also means you can't wait around for the compiler to add features.

Code Composer Studio™︎

Code Composer Studio forum

Is this a normal output ? What flags do I need ?