[processargs] Rename PA_SVC_LOADER to PA_LDSVC_LOADER

We ended up calling the loader service LDSVC in FIDL. This change aligns
the processargs name with the FIDL name.

Change-Id: I5cb2332f047676c2e49fa5b20719aa841185cf19

[syscall][vmo] removal of zx_vmo_{read,write}() actual parameter 4/n

This reverts commit d7c91f0a8a876bd4de8808595cafcd4f2c3fd7a1.

Change-Id: I5c61410f62850583a970d3ff2f44b6d58901509a

[revert] Revert "[syscall][vmo] removal of zx_vmo_{read,write}() actual parameter 4/n"

This reverts commit 2d25909b7ab244d73172c9f5bc11d85b49ccefbb.

Change-Id: I09efe4e1d69d7aeadb051936d3ddc8237e7d39cf

[syscall][vmo] removal of zx_vmo_{read,write}() actual parameter 4/n

Remove actual from zx_vmo_{read,write}
Mark zx_vmo_{read,write}_old as deprecated
Retarget most uses of zx_vmo_{read,write}_old to zx_vmo_{read,write}.

Still need to migrate a handful of uses of _old that had meaningful
usage of actual.
This is good enough to go ahead and migrate uses in Garnet and Topaz.

ZX-1802

Change-Id: If57329f9c5183a0dacd29083decbaf771925145f

[syscall][vmo] removal of zx_vmo_{read,write}() actual parameter 1/n

In preparation for changing the zx_vmo_read() and write() syscalls,
introduce aliases (zx_vmo_read_old() and write_old()) for the existing
behaviour, migrate zircon callers to the aliases, and mark the original
syscalls as deprecated.

Once the garnet and above layers have been migrated, the original
syscalls will be adjusted to remove the "actual" argument, and the
temporary _old() versions will be deprecated, and then removed.

ZX-1802

Change-Id: I2fab9a59caf4093fb585ada6015197017767aba2

[userboot] Print load addresses and entry points

Change-Id: I5e0b6c618c055a53ecf7c591604a0979e7f25c47

[zx] Magenta -> Zircon

The Great Renaming is here!

Change-Id: I3229bdeb2a3d0e40fb4db6fec8ca7d971fbffb94

[userboot] migrate from print() to printl()

Change-Id: I8764ab08368b6bfa32f2df968bbd64389b81de6a

[ulib][elfload] Remove unnecessary vmar_self parameter

This is no longer needed, so don't pass it down.

Change-Id: I28f995cb4a34a467b13074767a2b5b0006af086e

[processargs] tidy up naming and numbering

This cleans stuff up ahead of the addition of string tables for
the upcoming PA_NS_DIR and PA_NS_REQ types and the eventual
flattening of PA_MXIO_* to a single type, using subtypes for
protocol.

- Align names with current-day usage
- Organize numbering / ordering around subsystem usage
- Reduce "type" field to 8 bits
- Reserve space for "subtype" field
- Use PA_ namespace and shorter a lot of very long names

Change-Id: I5e59f412c3b9bd79d90f921a248a6d98d4b703bc

[core][userboot] Provide a basic loader service in userboot

This makes it possible for the initial program (usually devmgr)
to load additional shared libraries.

Change-Id: Ief65d8ec8705d47bbacbbeb85ec28811d4c3725e

[launchpad] Add script execution.

Adds support in launchpad for loading an interpreted script file,
with a new API function "launchpad_file_load".

Change-Id: Iba091890c9975c6066c7f5a38ad577879cd599c8

[processargs][userboot][launchpad] Plumb through MX_HND_TYPE_VMAR_LOADED

Add a processargs handle type for the VMAR used to load the initial
program image (usually the dynamic linker). This is passed down by
launchpad (and userboot), and received by the dynamic linker. It
enables the dynamic linker to apply RELRO page protections to its
own image after relocation.

Change-Id: Ib91933a41c52617207d33a631ff0436baf704ef1

[system] Use the countof() macro (for array sizes) in more places

Change-Id: I79973d43c9f16e518ce4801f046f7d4b9b1ef337

[core][userboot] Pass initial thread through bootstrap message.

This ensures that userboot provides access to the initial thread, so that any
operations that require the thread handle can be performed.

Change-Id: I4916eaae9e4b30944f7fc8180669ec3c9bfa74f3

[vmar][elf] Make the elf loader use VMARs

Change-Id: I1930a886b920f31de90d40d36b88840e1510f43b

Remove mx_size_t and mx_ssize_t types

mx_ssize_t is no longer used. mx_size_t is superfluous and
can be replaced by the standard C type size_t.

Change-Id: I2137af6f166099d2e8aaca4fab63ff101f2a43ac

[syscalls] update mx_handle_duplicate() and mx_handle_replace()

Change-Id: Ie332f4a924311c0bf1f93031712853c33027c411

[syscalls] update vmo_{create,read,write}()

Change-Id: I6b46a48813de4e74767174c2786d04cf414b017a

[core][userboot] Use 'channel' instead of deprecated 'msgpipe'

Change-Id: I9bbd6465f4e3978cc9ca9afe2983b72a4834efcc

[organization] move essential userspace components to system/core/...

userboot, devmgr, acpisvc, crashlogger, netsvc are essential to the
system booting and running. Pretty much everything else in system/uapp/..
is nonessential.

Change-Id: Ibbcf2b1c388bdefc28699226eab02e90aab895f0