pieeprom-2025-05-08: 2712: Implement TCP window for net boot (latest)

* arm_loader: Correct some mailbox response lengths
  The GET_GENCMD_RESULT mailbox handler was setting the wrong response
  length, and GET_FIRMWARE_COMMIT_HASH and GET_FIRMWARE_VARIANT were not
  setting any length.
  See: raspberrypi/firmware#1968
* Signed boot and HTTP boot mode
  HTTP boot mode is supposed to be disabled if signed boot is enabled and
  a host is not specified. The code is checking the http_secure flag to
  enforce this. But this is valid now we support custom CA certs.
  Only disable HTTP mode if we're using the default HOST.
* Implement TCP window for net boot
  The minimal IP stack used for https booting lacks the ability to cache
  packets received out of order, which can lead to severe slowdown when
  it happens. The problem seems to affect some ISPs more than others.
  The receive window implemented here copes with packet losses of 10%.
* netboot: Correct the TCP MSS
* rp1_net: Overwrite the length field
  Although concise, ORing in the packet length runs the risk of leaving
  some unwanted bits set. Ensure the length field is cleared before
  ORing in the required value.
* Correct msecs in debug timestamps
  The fractional part of timestamps in UART debug output was showing the
  100ths and 1000ths of a second, rather than 10ths and 100ths, causing
  strange sequences that appear to jump backwards.
* Implement GET_BOARD_MAC_ADDRESS on Pi5
  The Pi 5 EEPROM implements a subset of the original mailbox properties.
  Add GET_BOARD_MAC_ADDRESS to the subset.
  See: #698
* Ensure the initramfs matches the kernel
  As far as is possible, both the kernel and initramfs are matched to the
  device. However, where multiple kernel variants can run on a device, the
  initramfs must be matched to the chosen kernel. Make that the sole rule
  for initramfs selection, rather than duplicating the device matching
  logic.
  See: raspberrypi/firmware#1965
* Enable logging messages from OS loader
  Pi 5 EEPROM builds were missing the output from the main OS loading
  function, including some important diagnostics. Enabling the logging
  output from this loader code results in some near-duplicates, but is
  more user friendly and is available via "sudo vclog -m".

Author: timg236

firmware-2712/latest/pieeprom-2025-05-08.bin

@@ -1,5 +1,48 @@
 # Raspberry Pi5 bootloader EEPROM release notes
 
+## 2025-05-08: Implement TCP window for net boot (latest)
+
+* arm_loader: Correct some mailbox response lengths
+  The GET_GENCMD_RESULT mailbox handler was setting the wrong response
+  length, and GET_FIRMWARE_COMMIT_HASH and GET_FIRMWARE_VARIANT were not
+  setting any length.
+  See: https://github.com/raspberrypi/firmware/issues/1968
+* Signed boot and HTTP boot mode
+  HTTP boot mode is supposed to be disabled if signed boot is enabled and
+  a host is not specified. The code is checking the http_secure flag to
+  enforce this. But this is valid now we support custom CA certs.
+  Only disable HTTP mode if we're using the default HOST.
+* Implement TCP window for net boot
+  The minimal IP stack used for https booting lacks the ability to cache
+  packets received out of order, which can lead to severe slowdown when
+  it happens. The problem seems to affect some ISPs more than others.
+  The receive window implemented here copes with packet losses of 10%.
+* netboot: Correct the TCP MSS
+* rp1_net: Overwrite the length field
+  Although concise, ORing in the packet length runs the risk of leaving
+  some unwanted bits set. Ensure the length field is cleared before
+  ORing in the required value.
+* Correct msecs in debug timestamps
+  The fractional part of timestamps in UART debug output was showing the
+  100ths and 1000ths of a second, rather than 10ths and 100ths, causing
+  strange sequences that appear to jump backwards.
+* Implement GET_BOARD_MAC_ADDRESS on Pi5
+  The Pi 5 EEPROM implements a subset of the original mailbox properties.
+  Add GET_BOARD_MAC_ADDRESS to the subset.
+  See: https://github.com/raspberrypi/rpi-eeprom/issues/698
+* Ensure the initramfs matches the kernel
+  As far as is possible, both the kernel and initramfs are matched to the
+  device. However, where multiple kernel variants can run on a device, the
+  initramfs must be matched to the chosen kernel. Make that the sole rule
+  for initramfs selection, rather than duplicating the device matching
+  logic.
+  See: https://github.com/raspberrypi/firmware/issues/1965
+* Enable logging messages from OS loader
+  Pi 5 EEPROM builds were missing the output from the main OS loading
+  function, including some important diagnostics. Enabling the logging
+  output from this loader code results in some near-duplicates, but is
+  more user friendly and is available via "sudo vclog -m".
+
 ## 2025-04-07: arm_dt: Revert to using the max fan speed (latest)
 
 * arm_dt: Revert to using the max fan speed