Bartlomiej Sieka wrote: [...] > As part of adding support for the new uImage format, bootm command will > be reworked quite a bit. Below is a note that summarizes bootm usage > scenarios (present and planned), and defines extensions to bootm > arguments' syntax. The note, or its portions, can be later on added to > the tree as documentation.
Here's a revised note, with the following changes from the first version: - addressed Wolfgang's comments posted to the list - dropped support for standalone applications from bootm Looking forward to any comments, questions, etc. Thanks, Bartlomiej New syntax for bootm (v2) ========================= As part of adding support for new uImage format, bootm command (and other commands as well) will have to understand new syntax of the arguments. This is necessary in order to specify objects contained in the new uImage, on which bootm has to operate. This note attempts to first summarize both current and future bootm usage scenarios, and then introduces new argument syntax. bootm usage scenarios --------------------- Below is a summary of bootm usage scenarios, focused on booting a PowerPC Linux kernel. Some of the scenarios exist and are supported already, some will be extended/added along with the new uImage format. The purpose of the following list is to document a complete list of supported bootm usages. Note: U-Boot supports two methods of booting a PowerPC Linux kernel: old way, i.e., without passing the Flattened Device Tree (FDT), and new way, where the kernel is passed a pointer to the FDT. The boot method is indicated for each scenario. 1. bootm boot image at the current address, equivalent to 2,3,8 Old uImage: 2. bootm <addr1> /* single image at <addr1> */ 3. bootm <addr1> /* multi-image at <addr1> */ 4. bootm <addr1> - /* multi-image at <addr1> */ 5. bootm <addr1> <addr2> /* single image at <addr1> */ 6. bootm <addr1> <addr2> <addr3> /* single image at <addr1> */ 7. bootm <addr1> - <addr3> /* single image at <addr1> */ New uImage: 8. bootm <addr1> 9. bootm [<addr1>]:<subimg1> 10. bootm [<addr1>]#<conf> 11. bootm [<addr1>]:<subimg1> [<addr2>]:<subimg2> 12. bootm [<addr1>]:<subimg1> [<addr2>]:<subimg2> [<addr3>]:<subimg3> 13. bootm [<addr1>]:<subimg1> [<addr2>]:<subimg2> <addr3> 14. bootm [<addr1>]:<subimg1> - [<addr3>]:<subimg3> 15. bootm [<addr1>]:<subimg1> - <addr3> Ad. 1. This is equivalent to cases 2,3,8, depending on the type of image at the current image address. - boot method: see cases 2,3,8 Ad. 2. Boot kernel image located at <addr1>.ddr1> with initrd loaded with ramdisk <subimg2> from the image at <addr2>. - boot method: non-FDT Ad. 12. Equivalent to case 6: boot kernel stored in <subimg1> from the image at <addr1> with initrd loaded with ramdisk <subimg2> from the image at <addr2>, and pass FDT blob <subimg3> from the image at <addr3>. - boot method: FDT Ad. 13. Similar to case 12, the difference being that <addr3> is the address of FDT binary blob that is to be passed to the kernel. - boot method: FDT Ad. 14. Equivalent to case 7: boot kernel stored in <subimg1> from the image at <addr1>, without initrd, and pass FDT blob <subimg3> from the image at <addr3>. - boot method: FDT Ad. 15. Similar to case 14, the difference being that <addr3> is the address of the FDT binary blob that is to be passed to the kernel. - boot method: FDT Note on current image address ----------------------------- When bootm is called without arguments, the image at current image address is booted. The current image address is the address set most recently by a load command, etc, and is by default equal to CFG_LOAD_ADDR. For example, consider the following commands: tftp 200000 /tftpboot/kernel bootm Last command is equivalent to: bootm 200000 In case of the new uImage argument syntax, the address portion of any argument can be omitted. If <addr3> is omitted, then it is assumed that image at <addr2> should be used. Similarly, when <addr2> is omitted, is is assumed that image at <addr1> should be used. If <addr1> is omitted, it is assumed that the current image address is to be used. For example consider the following commands: tftp 200000 /tftpboot/uImage bootm :[EMAIL PROTECTED] Last command is equivalent to: bootm 200000:[EMAIL PROTECTED] tftp 200000 /tftpboot/uImage bootm 400000:[EMAIL PROTECTED] :[EMAIL PROTECTED] Last command is equivalent to: bootm 400000:[EMAIL PROTECTED] 400000:[EMAIL PROTECTED] tftp 200000 /tftpboot/uImage bootm :[EMAIL PROTECTED] 400000:[EMAIL PROTECTED] :[EMAIL PROTECTED] Last command is equivalent to: bootm 200000:[EMAIL PROTECTED] 400000:[EMAIL PROTECTED] 400000:[EMAIL PROTECTED] ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ U-Boot-Users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/u-boot-users
