Refactor bootm and Image Commands

Problems:

• bootm has gathered more and more variants of sequences for booting the target OS.
  • Kumar has created a bootm <subcmd> changeset to break the currently unbreakable sequence into steps that can be run sequentially and allows modifications (run commands) in between the bootm steps.
• image.c has grown large and unwieldy. This was aggravated by adding the FIT image handling to it.
  • Can we split the FIT image processing out into a fit_image.c file?

Sequence

1. fdt boardsetup
   • Do board-specific FDT setup
2. fdt chosen
   • Create the FDT /chosen node
3. interrupts off
   • Disable interrupts (need CONFIG_CMD_IRQ)
4. usb stop
   • USB stop (only if USB is supported)
5. dcache off ; icache off
   • Disable cache (only needed for the Amiga One 3SE
6. bootm start <os> <initrd> <fdtaddr>
   • bootm start $loadaddr $ramdiskaddr $fdtaddr
   • Sets the addresses…
7. bootm ramdisk
   • Copies the ramdisk to high memory, honoring the env variable initrd_high and leaving room for the logbuffer
8. bootm fdt
   • Copies the fdt to a "good" location
9. bootm bdt
   • Sets up the bd_t struct values (legacy)
10. bootm cmdline
    • Sets up the (linux) command line
11. bootm prepos
    • OS-specific preparations before relocation or go
12. bootm loados
    • Copies (with decompressing, if necessary) the OS to its execution address
13. bootm go

Original Sequence

1. Initialize / fill out the images structure
2. lmb
   • env specified region: =getenv_bootm_low(); / getenv_bootm_size();
   • board reserved region (optional): board_lmb_reserve(&lmb);
3. os_hdr = boot_get_kernel (cmdtp, flag, argc, argv, &images, &os_data, &os_len);
4. /* get image parameters */ (different methods of filling out these variables based on IMAGE_FORMAT_LEGACY or IMAGE_FORMAT_FIT)
   • type
   • comp
   • os
   • image_end
   • load_start
   • image_start
   • load_end (set to zero, filled in after decompressing)
   • type_name
5. Disable interrupts
6. USB stop (if CONFIG_CMD_USB)
7. Disable caches (if CONFIG_AMIGAONEG3SE)
8. Decompress the image (based on compression type)
   • Sets load_end to the proper value
9. Some sanity checking (load vs. image start and end, header validity)
10. Add image load region to lmb
11. OS-specific start function - should not return

• We need to support the ability to load the images but not actually transfer control to the OS
• We need to support the ability to modify the device tree before its handled to the OS. These modification need to be controlled at runtime and not compile time.

• Traditional: bootm <osaddr> [(-|<ramdisk>) [<fdtaddr>]]

=> bootm $loadaddr $ramdiskaddr $fdtaddr
## Booting kernel from Legacy Image at 00408000 …
   Image Name:   Linux-2.6.26-06077-gc010b2f
   Image Type:   PowerPC Linux Kernel Image (gzip compressed)
   Data Size:    1391935 Bytes =  1.3 MB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum … OK
## Loading init Ramdisk from Legacy Image at 01000000 …
   Image Name:   Simple Embedded Linux Framework
   Image Type:   PowerPC Linux RAMDisk Image (gzip compressed)
   Data Size:    1731902 Bytes =  1.7 MB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum … OK
## Flattened Device Tree blob at 00400000
   Booting using the fdt blob at 0x400000
   Uncompressing Kernel Image … OK
   Loading Ramdisk to 0fdf7000, end 0ff9dd3e … OK

Refactoring cmd_bootm.c

• External functions
  • extern int gunzip (void *dst, int dstlen, unsigned char *src, unsigned long *lenp);
  • extern void bz_internal_error(int);
  • extern flash_info_t flash_info[]; /* info for FLASH chips */ (used by "imls" command)
  • extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);

• Helper functions
  • static void fixup_silent_linux (void);
  • static image_header_t *image_get_kernel (ulong img_addr, int verify);
  • static int fit_check_kernel (const void *fit, int os_noffset, int verify);
  • static void *boot_get_kernel (cmd_tbl_t *cmdtp, int flag,int argc, char *argv[], bootm_headers_t *images, ulong *os_data, ulong *os_len);

• Board-specific helper functions
  • void board_lmb_reserve(struct lmb *lmb) __attribute__((weak, alias("__board_lmb_reserve")));

• Command functions
  • int do_bootm (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
  • static int image_info (unsigned long addr); - iminfo command
  • static int do_imls (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]); - imls command

• Function pointer
  • typedef void boot_os_fn (cmd_tbl_t cmdtp, int flag, int argc, char *argv[], bootm_headers_t *images); / pointers to os/initrd/fdt */
  • extern boot_os_fn do_bootm_linux; - Q: Why is this one extern? (Probably cause its implemented in the /bootm.c)
  • static boot_os_fn do_bootm_netbsd;
  • static boot_os_fn do_bootm_lynxkdi;
  • static boot_os_fn do_bootm_rtems;
  • static boot_os_fn do_bootm_vxworks;
  • static boot_os_fn do_bootm_qnxelf;
  • static boot_os_fn do_bootm_artos;
  • …and support functions used with the function pointers
    • extern void lynxkdi_boot (image_header_t *);
    • int do_bootvx (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
    • int do_bootelf (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);

Refactoring image.c

• External functions
  • Legacy image handling
    • int image_check_hcrc (image_header_t *hdr) (legacy support)
    • int image_check_dcrc (image_header_t *hdr) (legacy support)
    • ulong image_multi_count (image_header_t *hdr) (legacy support)
    • void image_multi_getimg (image_header_t *hdr, ulong idx, ulong *data, ulong *len) (legacy support)
    • void image_print_contents (image_header_t *hdr) (legacy support)
    • int boot_get_kbd (struct lmb *lmb, bd_t **kbd, ulong bootmap_base)
  • Externally available utility functions
    • int getenv_yesno (char *var) (utility)
    • ulong getenv_bootm_low(void) - returns the env variable bootm_low or, if not defined, the lowest address of RAM (utility)
    • phys_size_t getenv_bootm_size(void) - returns the env variable =bootm_size or, if not defined, the size of RAM (utility)
    • void memmove_wd (void *to, void *from, size_t len, ulong chunksz) - move memory, kicking the WDT
  • New image handling
    • int genimg_get_format (void *img_addr) - new image format detection and identification
    • ulong genimg_get_image (ulong img_addr)
    • int genimg_has_config (bootm_headers_t *images)
    • int boot_get_ramdisk (int argc, char *argv[], bootm_headers_t *images, uint8_t arch, ulong *rd_start, ulong *rd_end)
    • int boot_ramdisk_high (struct lmb *lmb, ulong rd_data, ulong rd_len, ulong *initrd_start, ulong *initrd_end) - used by lib_*/bootm.c - seems misplaced.
    • int boot_relocate_fdt (struct lmb *lmb, ulong bootmap_base, char **of_flat_tree, ulong *of_size)
    • int boot_get_fdt (int flag, int argc, char *argv[], bootm_headers_t *images, char **of_flat_tree, ulong *of_size)
    • int boot_get_cmdline (struct lmb *lmb, ulong *cmd_start, ulong *cmd_end, ulong bootmap_base)

• • Translate IDs to strings
    • const char *genimg_get_os_name (uint8_t os)
    • const char *genimg_get_arch_name (uint8_t arch)
    • const char *genimg_get_type_name (uint8_t type)
    • const char *genimg_get_comp_name (uint8_t comp)
  • Translate strings to IDs
    • int genimg_get_os_id (const char *name)
    • int genimg_get_arch_id (const char *name)
    • int genimg_get_type_id (const char *name)
    • int genimg_get_comp_id (const char *name)

• Helper functions
  • static void image_print_type (image_header_t *hdr)
  • static image_header_t* image_get_ramdisk (ulong rd_addr, uint8_t arch, int verify)
  • static void genimg_print_size (uint32_t size)
  • static void genimg_print_time (time_t timestamp)
  • static char *get_table_entry_name (table_entry_t *table, char *msg, int id) - translate an ID to a printable name
  • static int get_table_entry_id (table_entry_t *table, const char *table_name, const char *name)
  • static void fdt_error (const char *msg)
  • static image_header_t *image_get_fdt (ulong fdt_addr)
  • static int fit_check_fdt (const void *fit, int fdt_noffset, int verify)

• • static int fit_parse_spec (const char *spec, char sepc, ulong addr_curr, ulong *addr, const char **name)
  • inline int fit_parse_conf (const char *spec, ulong addr_curr, ulong *addr, const char **conf_name)
  • inline int fit_parse_subimage (const char *spec, ulong addr_curr, ulong *addr, const char **image_name)
  • static void fit_get_debug (const void *fit, int noffset, char *prop_name, int err)
  • void fit_print_contents (const void *fit)
  • void fit_image_print (const void *fit, int image_noffset, const char *p)
  • void fit_image_print_hash (const void *fit, int noffset, const char *p)
  • int fit_get_desc (const void *fit, int noffset, char **desc)
  • int fit_get_timestamp (const void *fit, int noffset, time_t *timestamp)
  • int fit_image_get_node (const void *fit, const char *image_uname)
  • int fit_image_get_os (const void *fit, int noffset, uint8_t *os)
  • int fit_image_get_arch (const void *fit, int noffset, uint8_t *arch)
  • int fit_image_get_type (const void *fit, int noffset, uint8_t *type)
  • int fit_image_get_comp (const void *fit, int noffset, uint8_t *comp)
  • int fit_image_get_load (const void *fit, int noffset, ulong *load)
  • int fit_image_get_entry (const void *fit, int noffset, ulong *entry)
  • int fit_image_get_data (const void *fit, int noffset, const void **data, size_t *size)
  • int fit_image_hash_get_algo (const void *fit, int noffset, char **algo)
  • int fit_image_hash_get_value (const void *fit, int noffset, uint8_t **value, int *value_len)
  • int fit_set_timestamp (void *fit, int noffset, time_t timestamp)
  • static int calculate_hash (const void *data, int data_len, const char *algo, uint8_t *value, int *value_len)
  • int fit_set_hashes (void *fit)
  • int fit_image_set_hashes (void *fit, int image_noffset)
  • int fit_image_hash_set_value (void *fit, int noffset, uint8_t *value, int value_len)
  • int fit_image_check_hashes (const void *fit, int image_noffset)
  • int fit_all_image_check_hashes (const void *fit)
  • int fit_image_check_os (const void *fit, int noffset, uint8_t os)
  • int fit_image_check_arch (const void *fit, int noffset, uint8_t arch)
  • int fit_image_check_type (const void *fit, int noffset, uint8_t type)
  • int fit_image_check_comp (const void *fit, int noffset, uint8_t comp)
  • int fit_check_format (const void *fit)
  • int fit_conf_get_node (const void *fit, const char *conf_uname)
  • static int __fit_conf_get_prop_node (const void *fit, int noffset, const char *prop_name)
  • int fit_conf_get_kernel_node (const void *fit, int noffset)
  • int fit_conf_get_ramdisk_node (const void *fit, int noffset)
  • int fit_conf_get_fdt_node (const void *fit, int noffset)
  • void fit_conf_print (const void *fit, int noffset, const char *p)
  • static int fit_check_ramdisk (const void *fit, int rd_noffset, uint8_t arch, int verify)

• Board-specific helper functions

• Command functions

• Function pointer

New Commands Thoughts…

This section is some thoughts about if we made an imload command with subcommands rather than shoehorning the image manipulation into the bootm command.

• I'm wondering whether the OS/ramdisk/fdtblob needs to be loaded into RAM separately. The fdtblob needs to be modified before booting, that needs to be separate. The ramdisk may not exist. Conclusion: yes, might as well do all of them separately.
• We already have a copy command for memory chunks and fdt move for fdtblobs. We should be able to script things using existing+new commands. Missing:
  • An "uncompress" command.
  • A way of getting addresses and length information from the images. Unfortunately, our hush shell doesn't implement back-ticks "`". We could hack our way around this by setting env variables as side effects. fUgly…

1. Copy fdt into destination address
2. Copy initrd into destination address
3. Decompress/copy OFP into destination address (requires interrupts disabled)

• imload fit <fitaddr>
  • Load a FIT image into appropriate locations
• imload os <osaddr>
  • Load an OS image into the appropriate location
  • Return (set env variables?) for start and end addresses
• imload ramdisk <ramdisk>
  • Load a RAMDISK image into the appropriate location
  • Return (set env variables?) for start and end addresses
  • What is needed is the ramdisk start address, destination address, and length. Then a cp command can do the move?!
• imload fdt <fdtaddr>
  • Load a FDT blob into the appropriate location
  • Return (set env variables?) for start and end addresses
  • What is needed is the blob start address, destination address, and length. Then a fdt move (or cp?) command can do the move?!

• bootm bdt
  • Sets up the bd_t struct values (legacy)
• bootm cmdline
  • Sets up the (linux) command line
• bootm prepos
  • OS-specific preparations before relocation or go
• bootm go