docs: Update "Getting Started Quickly"

Instructions in this document have become out of date.

Align the content with the "Chromium OS Developer Guide":
- Add missing package to fix local build error with libusb header
- Use ~/chromiumos folder for chroot to be consistent with dev guide
- Set missing env variable $BOARD
- Replace deprecated script ./build_pacakges
- Remove minilayout and use stable branch to make the build more
  reliable

BRANCH=none
BUG=b:219082979
TEST=View of Markdown preview in VSCode

Signed-off-by: Andrea Grandi <agrandi@google.com>
Change-Id: I3fdac3b346098575a0957394e80052626ecbb551
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3466428
Reviewed-by: Bobby Casey <bobbycasey@google.com>
Reviewed-by: Tom Hughes <tomhughes@chromium.org>

1 files changed, 25 insertions, 14 deletions

diff --git a/docs/getting_started_quickly.md b/docs/getting_started_quickly.md
index f9808c76da..0ef88a328e 100644
--- a/docs/getting_started_quickly.md
+++ b/docs/getting_started_quickly.md
@@ -19,10 +19,11 @@ toolchain incompatibilities may require extra debug.
 1.  Install build / dev tools:
 
     ```bash
-    sudo apt-get install git libftdi-dev libusb-dev libncurses5-dev gcc-arm-none-eabi
+    sudo apt-get install git libftdi-dev libusb-dev libusb-1.0-0-dev \
+         libncurses5-dev gcc-arm-none-eabi
     ```
 
-1.  Sync the cros-ec git repo:
+1.  Clone the cros-ec git repo:
 
     ```bash
     git clone https://chromium.googlesource.com/chromiumos/platform/ec
@@ -55,45 +56,55 @@ toolchain incompatibilities may require extra debug.
 Most boards are buildable, but some will fail due to dependencies on external
 binaries (such as [`futility`](#building-futility)). Also, some related tools
 (such as `flash_ec` and `servod`) must be run from the Chromium OS chroot. Here
-is a set of steps to setup a minimal development environment to build EC images
-from the Chromium OS chroot:
+is a set of steps to setup a development environment to build EC images from the
+Chromium OS chroot:
 
 1.  Create a folder for your chroot:
 
     ```bash
-    mkdir cros-src; cd cros-src
+    mkdir chromiumos; cd chromiumos
     ```
 
-1.  Run
+1.  Initialize the checkout in the current directory:
 
     ```bash
-    repo init -u https://chromium.googlesource.com/chromiumos/manifest -g minilayout,firmware
+    repo init -u https://chromium.googlesource.com/chromiumos/manifest -b stable
     ```
 
-1.  Run `repo sync`:
+    NOTE: The
+    [`-b stable` flag](https://chromium.googlesource.com/chromiumos/docs/+/HEAD/developer_guide.md#Sync-to-Green)
+    only works for Googlers. Remove it if you are developing externally.
+
+1.  Update the working tree to the latest version:
 
     ```bash
     repo sync -j <number of cores on your workstatsion>
     ```
 
-1.  Enter the chroot and enter your password for `sudo` if prompted:
+1.  Enter the chroot (type your password for `sudo` if prompted):
 
     ```bash
-    ./chromite/bin/cros_sdk
+    cros_sdk
     ```
 
+1.  Select a target board
+
+    ```bash
+    export BOARD=<target board>
+    ```
+
+    See previous section for recommendations.
+
 1.  Set up your board:
 
     ```bash
     setup_board --board=${BOARD}
     ```
 
-    (ex. `setup_board --board=glados`)
-
 1.  Build EC:
 
     ```bash
-    ./build_packages --board=${BOARD} chromeos-ec
+    build_packages --board=${BOARD} chromeos-ec
     ```
 
 1.  Now, EC images for any board can be built with:
@@ -105,7 +116,7 @@ from the Chromium OS chroot:
 ## Building `futility` outside the chroot {#building-futility}
 
 If you want to build the `futility` host tool outside the normal Chrome OS
-chroot self-contained environment, you can try the following
+chroot self-contained environment, you can try the following:
 
 1.  Install futility build dependencies: