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![Mario Six](/assets/img/avatar_default.png)
The Linux kernel moved to sphinx-based documentation and got rid of the DocBook based documentation quite a while ago. Hence, the DocBook documentation for U-Boot should be converted as well. To achieve this, import the necessary files from Linux v4.17, and convert the current DocBook documentation (three files altogether) to sphinx/reStructuredText. For now, all old DocBook documentation was merged into a single handbook, tentatively named "U-Boot Hacker Manual". For some source files, the documentation style was changed to comply with kernel-doc; no functional changes were applied. Signed-off-by: Mario Six <mario.six@gdsys.cc>
118 lines
3.2 KiB
ReStructuredText
118 lines
3.2 KiB
ReStructuredText
====================
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U-Boot Hacker Manual
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====================
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Linker-Generated Arrays
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=======================
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A linker list is constructed by grouping together linker input
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sections, each containing one entry of the list. Each input section
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contains a constant initialized variable which holds the entry's
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content. Linker list input sections are constructed from the list
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and entry names, plus a prefix which allows grouping all lists
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together. Assuming _list and _entry are the list and entry names,
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then the corresponding input section name is
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::
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.u_boot_list_ + 2_ + @_list + _2_ + @_entry
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and the C variable name is
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::
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_u_boot_list + _2_ + @_list + _2_ + @_entry
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This ensures uniqueness for both input section and C variable name.
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Note that the names differ only in the first character, "." for the
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section and "_" for the variable, so that the linker cannot confuse
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section and symbol names. From now on, both names will be referred
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to as
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::
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%u_boot_list_ + 2_ + @_list + _2_ + @_entry
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Entry variables need never be referred to directly.
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The naming scheme for input sections allows grouping all linker lists
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into a single linker output section and grouping all entries for a
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single list.
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Note the two '_2_' constant components in the names: their presence
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allows putting a start and end symbols around a list, by mapping
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these symbols to sections names with components "1" (before) and
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"3" (after) instead of "2" (within).
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Start and end symbols for a list can generally be defined as
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::
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%u_boot_list_2_ + @_list + _1_...
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%u_boot_list_2_ + @_list + _3_...
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Start and end symbols for the whole of the linker lists area can be
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defined as
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::
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%u_boot_list_1_...
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%u_boot_list_3_...
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Here is an example of the sorted sections which result from a list
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"array" made up of three entries : "first", "second" and "third",
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iterated at least once.
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::
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.u_boot_list_2_array_1
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.u_boot_list_2_array_2_first
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.u_boot_list_2_array_2_second
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.u_boot_list_2_array_2_third
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.u_boot_list_2_array_3
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If lists must be divided into sublists (e.g. for iterating only on
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part of a list), one can simply give the list a name of the form
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'outer_2_inner', where 'outer' is the global list name and 'inner'
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is the sub-list name. Iterators for the whole list should use the
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global list name ("outer"); iterators for only a sub-list should use
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the full sub-list name ("outer_2_inner").
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Here is an example of the sections generated from a global list
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named "drivers", two sub-lists named "i2c" and "pci", and iterators
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defined for the whole list and each sub-list:
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::
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%u_boot_list_2_drivers_1
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%u_boot_list_2_drivers_2_i2c_1
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%u_boot_list_2_drivers_2_i2c_2_first
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%u_boot_list_2_drivers_2_i2c_2_first
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%u_boot_list_2_drivers_2_i2c_2_second
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%u_boot_list_2_drivers_2_i2c_2_third
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%u_boot_list_2_drivers_2_i2c_3
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%u_boot_list_2_drivers_2_pci_1
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%u_boot_list_2_drivers_2_pci_2_first
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%u_boot_list_2_drivers_2_pci_2_second
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%u_boot_list_2_drivers_2_pci_2_third
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%u_boot_list_2_drivers_2_pci_3
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%u_boot_list_2_drivers_3
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.. kernel-doc:: include/linker_lists.h
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:internal:
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Serial system
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=============
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.. kernel-doc:: drivers/serial/serial.c
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:internal:
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The U-Boot EFI subsystem
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========================
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Boot services
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-------------
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.. kernel-doc:: lib/efi_loader/efi_boottime.c
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:internal:
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