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Commit | Line | Data |
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045b4d2d | 1 | By Vlad Lungu vlad.lungu@windriver.com 2007-Oct-01 |
0764c164 VL |
2 | ---------------------------------------- |
3 | Qemu is a full system emulator. See | |
4 | ||
5b2da6a3 | 5 | http://www.nongnu.org/qemu/ |
0764c164 VL |
6 | |
7 | Limitations & comments | |
8 | ---------------------- | |
9 | Supports the "-m mips" configuration of qemu: serial,NE2000,IDE. | |
10 | Support is big endian only for now (or at least this is what I tested). | |
11 | Derived from au1x00 with a lot of things cut out. | |
045b4d2d VL |
12 | |
13 | Supports emulated flash (patch Jean-Christophe PLAGNIOL-VILLARD) with | |
14 | recent qemu versions. When using emulated flash, launch with | |
15 | -pflash <filename> and erase mips_bios.bin. | |
702e6014 WD |
16 | |
17 | ||
18 | ||
19 | Notes for the Qemu MIPS port | |
20 | ---------------------------- | |
21 | ||
22 | I) Example usage: | |
23 | ||
24 | # ln -s u-boot.bin mips_bios.bin | |
25 | start it: | |
26 | qemu-system-mips -L . /dev/null -nographic | |
27 | ||
28 | or | |
29 | ||
30 | if you use a qemu version after commit 4224 | |
31 | ||
32 | create image: | |
33 | # dd of=flash bs=1k count=4k if=/dev/zero | |
34 | # dd of=flash bs=1k conv=notrunc if=u-boot.bin | |
35 | start it: | |
36 | # qemu-system-mips -M mips -pflash flash -monitor null -nographic | |
37 | ||
38 | 2) Download kernel + initrd | |
39 | ||
40 | On ftp://ftp.denx.de/pub/contrib/Jean-Christophe_Plagniol-Villard/qemu_mips/ | |
41 | you can downland | |
42 | ||
43 | #config to build the kernel | |
44 | qemu_mips_defconfig | |
45 | #patch to fix mips interrupt init on 2.6.24.y kernel | |
46 | qemu_mips_kernel.patch | |
47 | initrd.gz | |
48 | vmlinux | |
49 | vmlinux.bin | |
50 | System.map | |
51 | ||
52 | 4) Generate uImage | |
53 | ||
54 | # tools/mkimage -A mips -O linux -T kernel -C gzip -a 0x80010000 -e 0x80245650 -n "Linux 2.6.24.y" -d vmlinux.bin.gz uImage | |
55 | ||
56 | 5) Copy uImage to Flash | |
57 | # dd if=uImage bs=1k conv=notrunc seek=224 of=flash | |
58 | ||
59 | 6) Generate Ide Disk | |
60 | ||
61 | # dd of=ide bs=1k cout=100k if=/dev/zero | |
62 | ||
63 | # sfdisk -C 261 -d ide | |
64 | # partition table of ide | |
65 | unit: sectors | |
66 | ||
67 | ide1 : start= 63, size= 32067, Id=83 | |
68 | ide2 : start= 32130, size= 32130, Id=83 | |
69 | ide3 : start= 64260, size= 4128705, Id=83 | |
70 | ide4 : start= 0, size= 0, Id= 0 | |
71 | ||
72 | 7) Copy to ide | |
73 | ||
74 | # dd if=uImage bs=512 conv=notrunc seek=63 of=ide | |
75 | ||
76 | 8) Generate ext2 on part 2 on Copy uImage and initrd.gz | |
77 | ||
78 | # Attached as loop device ide offset = 32130 * 512 | |
79 | # losetup -o 16450560 -f ide | |
80 | # Format as ext2 ( arg2 : nb blocks) | |
81 | # mke2fs /dev/loop0 16065 | |
82 | # losetup -d /dev/loop0 | |
83 | # Mount and copy uImage and initrd.gz to it | |
84 | # mount -o loop,offset=16450560 -t ext2 ide /mnt | |
85 | # mkdir /mnt/boot | |
86 | # cp {initrd.gz,uImage} /mnt/boot/ | |
87 | # Umount it | |
88 | # umount /mnt | |
89 | ||
90 | 9) Set Environment | |
91 | ||
92 | setenv rd_start 0x80800000 | |
93 | setenv rd_size 2663940 | |
94 | setenv kernel BFC38000 | |
95 | setenv oad_addr 80500000 | |
96 | setenv load_addr2 80F00000 | |
97 | setenv kernel_flash BFC38000 | |
98 | setenv load_addr_hello 80200000 | |
99 | setenv bootargs 'root=/dev/ram0 init=/bin/sh' | |
100 | setenv load_rd_ext2 'ide res; ext2load ide 0:2 ${rd_start} /boot/initrd.gz' | |
101 | setenv load_rd_tftp 'tftp ${rd_start} /initrd.gz' | |
102 | setenv load_kernel_hda 'ide res; diskboot ${load_addr} 0:2' | |
103 | setenv load_kernel_ext2 'ide res; ext2load ide 0:2 ${load_addr} /boot/uImage' | |
104 | setenv load_kernel_tftp 'tftp ${load_addr} /qemu_mips/uImage' | |
105 | setenv boot_ext2_ext2 'run load_rd_ext2; run load_kernel_ext2; run addmisc; bootm ${load_addr}' | |
106 | setenv boot_ext2_flash 'run load_rd_ext2; run addmisc; bootm ${kernel_flash}' | |
107 | setenv boot_ext2_hda 'run load_rd_ext2; run load_kernel_hda; run addmisc; bootm ${load_addr}' | |
108 | setenv boot_ext2_tftp 'run load_rd_ext2; run load_kernel_tftp; run addmisc; bootm ${load_addr}' | |
109 | setenv boot_tftp_hda 'run load_rd_tftp; run load_kernel_hda; run addmisc; bootm ${load_addr}' | |
110 | setenv boot_tftp_ext2 'run load_rd_tftp; run load_kernel_ext2; run addmisc; bootm ${load_addr}' | |
111 | setenv boot_tftp_flash 'run load_rd_tftp; run addmisc; bootm ${kernel_flash}' | |
112 | setenv boot_tftp_tftp 'run load_rd_tftp; run load_kernel_tftp; run addmisc; bootm ${load_addr}' | |
113 | setenv load_hello_tftp 'tftp ${load_addr_hello} /examples/hello_world.bin' | |
114 | setenv go_tftp 'run load_hello_tftp; go ${load_addr_hello}' | |
115 | setenv addmisc 'setenv bootargs ${bootargs} console=ttyS0,${baudrate} rd_start=${rd_start} rd_size=${rd_size} ethaddr=${ethaddr}' | |
116 | setenv bootcmd 'run boot_tftp_flash' | |
117 | ||
118 | 10) Now you can boot from flash, ide, ide+ext2 and tfp | |
119 | ||
120 | # qemu-system-mips -M mips -pflash flash -monitor null -nographic -net nic -net user -tftp `pwd` -hda ide | |
121 | ||
122 | II) How to debug U-Boot | |
123 | ||
124 | In order to debug U-Boot you need to start qemu with gdb server support (-s) | |
125 | and waiting the connection to start the CPU (-S) | |
126 | ||
127 | # qemu-system-mips -S -s -M mips -pflash flash -monitor null -nographic -net nic -net user -tftp `pwd` -hda ide | |
128 | ||
129 | in an other console you start gdb | |
130 | ||
131 | 1) Debugging of U-Boot Before Relocation | |
132 | ||
133 | Before relocation, the addresses in the ELF file can be used without any problems | |
134 | by connecting to the gdb server localhost:1234 | |
135 | ||
136 | # mipsel-unknown-linux-gnu-gdb u-boot | |
137 | GNU gdb 6.6 | |
138 | Copyright (C) 2006 Free Software Foundation, Inc. | |
139 | GDB is free software, covered by the GNU General Public License, and you are | |
140 | welcome to change it and/or distribute copies of it under certain conditions. | |
141 | Type "show copying" to see the conditions. | |
142 | There is absolutely no warranty for GDB. Type "show warranty" for details. | |
143 | This GDB was configured as "--host=i486-linux-gnu --target=mipsel-unknown-linux-gnu"... | |
144 | (gdb) target remote localhost:1234 | |
145 | Remote debugging using localhost:1234 | |
146 | _start () at start.S:64 | |
147 | 64 RVECENT(reset,0) /* U-boot entry point */ | |
148 | Current language: auto; currently asm | |
149 | (gdb) b board.c:289 | |
150 | Breakpoint 1 at 0xbfc00cc8: file board.c, line 289. | |
151 | (gdb) c | |
152 | Continuing. | |
153 | ||
154 | Breakpoint 1, board_init_f (bootflag=<value optimized out>) at board.c:290 | |
155 | 290 relocate_code (addr_sp, id, addr); | |
156 | Current language: auto; currently c | |
157 | (gdb) p/x addr | |
158 | $1 = 0x87fa0000 | |
159 | ||
160 | 2) Debugging of U-Boot After Relocation | |
161 | ||
162 | For debugging U-Boot after relocation we need to know the address to which | |
163 | U-Boot relocates itself to 0x87fa0000 by default. | |
164 | And replace the symbol table to this offset. | |
165 | ||
166 | (gdb) symbol-file | |
167 | Discard symbol table from `/private/u-boot-arm/u-boot'? (y or n) y | |
168 | Error in re-setting breakpoint 1: | |
169 | No symbol table is loaded. Use the "file" command. | |
170 | No symbol file now. | |
171 | (gdb) add-symbol-file u-boot 0x87fa0000 | |
172 | add symbol table from file "u-boot" at | |
173 | .text_addr = 0x87fa0000 | |
174 | (y or n) y | |
175 | Reading symbols from /private/u-boot-arm/u-boot...done. | |
176 | Breakpoint 1 at 0x87fa0cc8: file board.c, line 289. | |
177 | (gdb) c | |
178 | Continuing. | |
179 | ||
180 | Program received signal SIGINT, Interrupt. | |
181 | 0xffffffff87fa0de4 in udelay (usec=<value optimized out>) at time.c:78 | |
182 | 78 while ((tmo - read_c0_count()) < 0x7fffffff) |