]>
Commit | Line | Data |
---|---|---|
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 | ---------------------- | |
0f17f59c | 9 | Supports the "-M mips" configuration of qemu: serial,NE2000,IDE. |
2b086ce4 | 10 | Supports little and big endian as well as 32 bit and 64 bit. |
0764c164 | 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 | ||
2b086ce4 | 24 | Using u-boot.bin as ROM (replaces Qemu monitor): |
702e6014 | 25 | |
2b086ce4 DS |
26 | 32 bit, big endian: |
27 | # make qemu_mips | |
28 | # qemu-system-mips -M mips -bios u-boot.bin -nographic | |
29 | ||
30 | 32 bit, little endian: | |
31 | # make qemu_mipsel | |
32 | # qemu-system-mipsel -M mips -bios u-boot.bin -nographic | |
33 | ||
34 | 64 bit, big endian: | |
35 | # make qemu_mips64 | |
36 | # qemu-system-mips64 -cpu MIPS64R2-generic -M mips -bios u-boot.bin -nographic | |
37 | ||
38 | 64 bit, little endian: | |
39 | # make qemu_mips64el | |
40 | # qemu-system-mips64el -cpu MIPS64R2-generic -M mips -bios u-boot.bin -nographic | |
41 | ||
42 | or using u-boot.bin from emulated flash: | |
702e6014 WD |
43 | |
44 | if you use a qemu version after commit 4224 | |
45 | ||
46 | create image: | |
47 | # dd of=flash bs=1k count=4k if=/dev/zero | |
48 | # dd of=flash bs=1k conv=notrunc if=u-boot.bin | |
2b086ce4 DS |
49 | start it (see above): |
50 | # qemu-system-mips[64][el] [-cpu MIPS64R2-generic] -M mips -pflash flash -nographic | |
702e6014 WD |
51 | |
52 | 2) Download kernel + initrd | |
53 | ||
54 | On ftp://ftp.denx.de/pub/contrib/Jean-Christophe_Plagniol-Villard/qemu_mips/ | |
55 | you can downland | |
56 | ||
57 | #config to build the kernel | |
58 | qemu_mips_defconfig | |
59 | #patch to fix mips interrupt init on 2.6.24.y kernel | |
60 | qemu_mips_kernel.patch | |
61 | initrd.gz | |
62 | vmlinux | |
63 | vmlinux.bin | |
64 | System.map | |
65 | ||
66 | 4) Generate uImage | |
67 | ||
68 | # 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 | |
69 | ||
70 | 5) Copy uImage to Flash | |
71 | # dd if=uImage bs=1k conv=notrunc seek=224 of=flash | |
72 | ||
73 | 6) Generate Ide Disk | |
74 | ||
75 | # dd of=ide bs=1k cout=100k if=/dev/zero | |
76 | ||
77 | # sfdisk -C 261 -d ide | |
78 | # partition table of ide | |
79 | unit: sectors | |
80 | ||
81 | ide1 : start= 63, size= 32067, Id=83 | |
82 | ide2 : start= 32130, size= 32130, Id=83 | |
83 | ide3 : start= 64260, size= 4128705, Id=83 | |
84 | ide4 : start= 0, size= 0, Id= 0 | |
85 | ||
86 | 7) Copy to ide | |
87 | ||
88 | # dd if=uImage bs=512 conv=notrunc seek=63 of=ide | |
89 | ||
90 | 8) Generate ext2 on part 2 on Copy uImage and initrd.gz | |
91 | ||
92 | # Attached as loop device ide offset = 32130 * 512 | |
93 | # losetup -o 16450560 -f ide | |
94 | # Format as ext2 ( arg2 : nb blocks) | |
95 | # mke2fs /dev/loop0 16065 | |
96 | # losetup -d /dev/loop0 | |
97 | # Mount and copy uImage and initrd.gz to it | |
98 | # mount -o loop,offset=16450560 -t ext2 ide /mnt | |
99 | # mkdir /mnt/boot | |
100 | # cp {initrd.gz,uImage} /mnt/boot/ | |
101 | # Umount it | |
102 | # umount /mnt | |
103 | ||
104 | 9) Set Environment | |
105 | ||
106 | setenv rd_start 0x80800000 | |
107 | setenv rd_size 2663940 | |
108 | setenv kernel BFC38000 | |
109 | setenv oad_addr 80500000 | |
110 | setenv load_addr2 80F00000 | |
111 | setenv kernel_flash BFC38000 | |
112 | setenv load_addr_hello 80200000 | |
113 | setenv bootargs 'root=/dev/ram0 init=/bin/sh' | |
114 | setenv load_rd_ext2 'ide res; ext2load ide 0:2 ${rd_start} /boot/initrd.gz' | |
115 | setenv load_rd_tftp 'tftp ${rd_start} /initrd.gz' | |
116 | setenv load_kernel_hda 'ide res; diskboot ${load_addr} 0:2' | |
117 | setenv load_kernel_ext2 'ide res; ext2load ide 0:2 ${load_addr} /boot/uImage' | |
118 | setenv load_kernel_tftp 'tftp ${load_addr} /qemu_mips/uImage' | |
119 | setenv boot_ext2_ext2 'run load_rd_ext2; run load_kernel_ext2; run addmisc; bootm ${load_addr}' | |
120 | setenv boot_ext2_flash 'run load_rd_ext2; run addmisc; bootm ${kernel_flash}' | |
121 | setenv boot_ext2_hda 'run load_rd_ext2; run load_kernel_hda; run addmisc; bootm ${load_addr}' | |
122 | setenv boot_ext2_tftp 'run load_rd_ext2; run load_kernel_tftp; run addmisc; bootm ${load_addr}' | |
123 | setenv boot_tftp_hda 'run load_rd_tftp; run load_kernel_hda; run addmisc; bootm ${load_addr}' | |
124 | setenv boot_tftp_ext2 'run load_rd_tftp; run load_kernel_ext2; run addmisc; bootm ${load_addr}' | |
125 | setenv boot_tftp_flash 'run load_rd_tftp; run addmisc; bootm ${kernel_flash}' | |
126 | setenv boot_tftp_tftp 'run load_rd_tftp; run load_kernel_tftp; run addmisc; bootm ${load_addr}' | |
127 | setenv load_hello_tftp 'tftp ${load_addr_hello} /examples/hello_world.bin' | |
128 | setenv go_tftp 'run load_hello_tftp; go ${load_addr_hello}' | |
129 | setenv addmisc 'setenv bootargs ${bootargs} console=ttyS0,${baudrate} rd_start=${rd_start} rd_size=${rd_size} ethaddr=${ethaddr}' | |
130 | setenv bootcmd 'run boot_tftp_flash' | |
131 | ||
132 | 10) Now you can boot from flash, ide, ide+ext2 and tfp | |
133 | ||
134 | # qemu-system-mips -M mips -pflash flash -monitor null -nographic -net nic -net user -tftp `pwd` -hda ide | |
135 | ||
136 | II) How to debug U-Boot | |
137 | ||
138 | In order to debug U-Boot you need to start qemu with gdb server support (-s) | |
139 | and waiting the connection to start the CPU (-S) | |
140 | ||
141 | # qemu-system-mips -S -s -M mips -pflash flash -monitor null -nographic -net nic -net user -tftp `pwd` -hda ide | |
142 | ||
143 | in an other console you start gdb | |
144 | ||
145 | 1) Debugging of U-Boot Before Relocation | |
146 | ||
147 | Before relocation, the addresses in the ELF file can be used without any problems | |
148 | by connecting to the gdb server localhost:1234 | |
149 | ||
150 | # mipsel-unknown-linux-gnu-gdb u-boot | |
151 | GNU gdb 6.6 | |
152 | Copyright (C) 2006 Free Software Foundation, Inc. | |
153 | GDB is free software, covered by the GNU General Public License, and you are | |
154 | welcome to change it and/or distribute copies of it under certain conditions. | |
155 | Type "show copying" to see the conditions. | |
156 | There is absolutely no warranty for GDB. Type "show warranty" for details. | |
157 | This GDB was configured as "--host=i486-linux-gnu --target=mipsel-unknown-linux-gnu"... | |
158 | (gdb) target remote localhost:1234 | |
159 | Remote debugging using localhost:1234 | |
160 | _start () at start.S:64 | |
161 | 64 RVECENT(reset,0) /* U-boot entry point */ | |
162 | Current language: auto; currently asm | |
163 | (gdb) b board.c:289 | |
164 | Breakpoint 1 at 0xbfc00cc8: file board.c, line 289. | |
165 | (gdb) c | |
166 | Continuing. | |
167 | ||
168 | Breakpoint 1, board_init_f (bootflag=<value optimized out>) at board.c:290 | |
169 | 290 relocate_code (addr_sp, id, addr); | |
170 | Current language: auto; currently c | |
171 | (gdb) p/x addr | |
172 | $1 = 0x87fa0000 | |
173 | ||
174 | 2) Debugging of U-Boot After Relocation | |
175 | ||
176 | For debugging U-Boot after relocation we need to know the address to which | |
177 | U-Boot relocates itself to 0x87fa0000 by default. | |
178 | And replace the symbol table to this offset. | |
179 | ||
180 | (gdb) symbol-file | |
181 | Discard symbol table from `/private/u-boot-arm/u-boot'? (y or n) y | |
182 | Error in re-setting breakpoint 1: | |
183 | No symbol table is loaded. Use the "file" command. | |
184 | No symbol file now. | |
185 | (gdb) add-symbol-file u-boot 0x87fa0000 | |
186 | add symbol table from file "u-boot" at | |
187 | .text_addr = 0x87fa0000 | |
188 | (y or n) y | |
189 | Reading symbols from /private/u-boot-arm/u-boot...done. | |
190 | Breakpoint 1 at 0x87fa0cc8: file board.c, line 289. | |
191 | (gdb) c | |
192 | Continuing. | |
193 | ||
194 | Program received signal SIGINT, Interrupt. | |
195 | 0xffffffff87fa0de4 in udelay (usec=<value optimized out>) at time.c:78 | |
196 | 78 while ((tmo - read_c0_count()) < 0x7fffffff) |