Hello, I've written some very simple assembler code (included as test.S) and compiled it with "arm-linux-gcc -c test.S". The disassembled code (included as output.txt) shows that the branches are not pointed to the right address. Any idea what would cause this? Something missing in the source file, or a compile option, or a compiler bug? Please CC responses to me, as I'm not subscribed to the list. Scottie Shore <umshore4@xxxxxxxxxxxxxxx> - In general, if you notice double vision, you've gone too far.
test.o: file format elf32-littlearm Disassembly of section .text: 00000000 <.text>: 0: e59f003c ldr r0, [pc, #60] ; 44 <TEST_PATTERN> 4: eb000001 bl 10 <transmit+0x4> 8: eaffffff b c <transmit> c: e59f2038 ldr r2, [pc, #56] ; 4c <UTSR1> 10: e5921000 ldr r1, [r2] 14: e3110004 tst r1, #4 ; 0x4 18: 1a000008 bne 40 <fifo_free+0x18> 1c: e5921000 ldr r1, [r2] 20: e3110004 tst r1, #4 ; 0x4 24: 0a000005 beq 40 <fifo_free+0x18> 28: e59f2018 ldr r2, [pc, #24] ; 48 <UTDR> 2c: e20000ff and r0, r0, #255 ; 0xff 30: e5921000 ldr r1, [r2] 34: e3c110ff bic r1, r1, #255 ; 0xff 38: e1800001 orr r0, r0, r1 3c: e5820000 str r0, [r2] 40: e1a0f00e mov pc, lr 44: 2b2b2b2b blcs acacf8 <UTSR1+0xacacac> 48: 80050014 andhi r0, r5, r4, lsl r0 4c: 80050020 andhi r0, r5, r0, lsr #32
.text ldr r0, TEST_PATTERN loop: bl transmit b loop /* serial output code */ transmit: ldr r2, UTSR1 ldr r1, [r2] tst r1, #4 bne fifo_free fifo_full: /* we don't bother handling timeouts here */ ldr r1, [r2] tst r1, #4 beq fifo_full fifo_free: ldr r2, UTDR and r0, r0, #0xff ldr r1, [r2] bic r1, r1, #0xff orr r0, r0, r1 str r0, [r2] mov pc, lr TEST_PATTERN: .word 0x2b2b2b2b UTDR: .word 0x80050014 UTSR1: .word 0x80050020
