2009-01-14

• Trac Wiki 改名的終極方法: 到 db/trac.db 去改內容

  # sqlite3 db/trac.db
  sqlite> update wiki set name='BOINC/Server' where name='BOINC_Server';
  

• 如果有附件(Attachment)的話，比較麻煩 (1) 改 wiki (2) 改 attachment (3) 必須到 attachments/wiki/ 目錄去搬檔案

  # sqlite3 db/trac.db
  sqlite> update wiki set name='FlyCircuit/2008-03-26' where name='FlyCircit/2008-03-26';
  sqlite> update attachment set id='FlyCircuit/2008-03-26' where id='FlyCircit/2008-03-26';
  sqlite> update wiki set name='FlyCircuit/2008-06-24' where name='FlyCircit/2008-06-24';
  sqlite> update attachment set id='FlyCircuit/2008-06-24' where id='FlyCircit/2008-06-24';
  

BUGFIX: jfbterm (4)

• （續 08-11-15@GMT-6 BUGFIX: jfbterm (1)）
• （續 08-11-16@GMT-6 BUGFIX: jfbterm (2)）
• （續 08-11-17@GMT-6 BUGFIX: jfbterm (3)）

• 在看 fbcommon.c 時，發現在這組出現錯誤的 mmap 前曾跑過另一組 mmap, 因此把參數印出來對照看看。
• gdb debug 程序

  file jfbterm
  set args -e ls
  show args
  break fbcommon.c:500
  break fbcommon.c:557
  break fbcommon.c:566
  run
  p fb_fix
  c
  p fb_fix
  c
  p fb_fix.smem_len
  p p->soff
  p p->slen
  p fb_fix.mmio_len
  p p->moff
  p p->mlen
  

  root@intrepid:~/jfbterm-0.4.7-dev# gdb
  GNU gdb 6.8-debian
  Copyright (C) 2008 Free Software Foundation, Inc.
  License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
  This is free software: you are free to change and redistribute it.
  There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
  and "show warranty" for details.
  This GDB was configured as "x86_64-linux-gnu".
  (gdb) file jfbterm
  Reading symbols from /root/jfbterm-0.4.7-dev/jfbterm...done.
  (gdb) set args -e ls
  (gdb) show args
  Argument list to give program being debugged when it is started is "-e ls".
  (gdb) break fbcommon.c:500
  Breakpoint 1 at 0x40303d: file fbcommon.c, line 500.
  (gdb) break fbcommon.c:557
  Breakpoint 2 at 0x40327e: file fbcommon.c, line 557.
  (gdb) break fbcommon.c:566
  Breakpoint 3 at 0x403301: file fbcommon.c, line 566.
  (gdb) run
  Starting program: /root/jfbterm-0.4.7-dev/jfbterm -e ls
  ...略...
  Breakpoint 1, tfbm_open (p=0x6146e0) at fbcommon.c:501
  501             if (fb_var.yres_virtual != fb_var.yres) {
  (gdb) p fb_fix
  $1 = {id = "▒\204▒▒Q\177\000\000\006\000\000\000\000\000\000", smem_start = 21037808, 
    smem_len = 4269392626, type = 32593, type_aux = 0, visual = 0,
    xpanstep = 65535, ypanstep = 65535, ywrapstep = 65535, line_length = 1, mmio_start = 15, 
    mmio_len = 21076240, accel = 0, reserved = {53071, 64, 0}}
  (gdb) c
  Continuing.
  ...略...
  Breakpoint 2, tfbm_open (p=0x6146e0) at fbcommon.c:557
  557             p->smem = (u_char*)mmap(NULL, p->slen, PROT_READ|PROT_WRITE,
  (gdb) p fb_fix
  $2 = {id = "VESA VGA\000\000\000\000\000\000\000", smem_start = 4026531840, 
    smem_len = 1572864, type = 0, type_aux = 0, visual = 3, xpanstep = 0,
    ypanstep = 0, ywrapstep = 0, line_length = 1024, mmio_start = 0, 
    mmio_len = 0, accel = 0, reserved = {0, 0, 0}}
  (gdb) c
  Continuing.
  
  Breakpoint 3, tfbm_open (p=0x6146e0) at fbcommon.c:566
  566             if(p->mlen == 0)
  (gdb) p fb_fix.smem_len
  $3 = 1572864
  (gdb) p p->soff
  $4 = 0
  (gdb) p p->slen
  $5 = 1572864
  (gdb) p fb_fix.mmio_len
  $6 = 0
  (gdb) p p->moff
  $7 = 0
  (gdb) p p->mlen
  $8 = 0
  

fb_fix.smem_len = 1572864	p->soff = 0	p->slen = 1572864	mmap 成功
fb_fix.mmio_len = 0	p->moff = 0	p->mlen = 0	mmap 失敗 (因為 length = 0)

• 從數據看起來，無論是從 SSH 登入，或在本機 tty 使用，所得到的 fb_fix.mmio_len = 0 是主要原因。只是 mmio 所代表的意涵，fbcommon.h 程式碼並無註解。

  <fbcommon.c>
  
  509         tfbm_get_fix_screen_info(p->fh, &fb_fix);
  
  244 static void tfbm_get_fix_screen_info(int fh, struct fb_fix_screeninfo *fix)
  245 {
  246         if (ioctl(fh, FBIOGET_FSCREENINFO, fix)) {
  247                 print_strerror_and_exit("ioctl FBIOGET_FSCREENINFO");
  248         }
  249 }