🧪 Shrink bootloader ISA and RAM requirements (#1118)

CHANGELOG.md

@@ -29,6 +29,7 @@ mimpid = 0x01040312 -> Version 01.04.03.12 -> v1.4.3.12
 
 | Date | Version | Comment | Ticket |
 |:----:|:-------:|:--------|:------:|
+| 11.12.2024 | 1.10.7.1 | :test_tube: shrink bootloader's minimal ISA (`rv32e`) and RAM (256 bytes) requirements | [#1118](https://github.com/stnolting/neorv32/pull/1118) |
 | 10.12.2024 | [**:rocket:1.10.7**](https://github.com/stnolting/neorv32/releases/tag/v1.10.7) | **New release** | |
 | 03.12.2024 | 1.10.6.9 | :sparkles: add ONEWIRE command and data FIFO; :warning: rework ONEWIRE interface register layout; :bug: fix regression: busy flag was stuck at zero | [#1113](https://github.com/stnolting/neorv32/pull/1113) |
 | 01.12.2024 | 1.10.6.8 | add TWI bus sensing logic | [#1111](https://github.com/stnolting/neorv32/pull/1111) |

docs/datasheet/software_bootloader.adoc

@@ -6,7 +6,14 @@
 This section refers to the **default** NEORV32 bootloader. A pre-compiled memory image for the processor-internal
 <<_bootloader_rom_bootrom>> is available in the project's +rtl+ folder: `rtl/core/neorv32_bootloader_image.vhd`.
 This image is automatically inserted into the boot ROM when synthesizing the processor with the bootloader being
-enabled. **Note that the default bootloader image was compiled for a minimal `rv32i` + priv. ISA!**
+enabled.
+
+.Minimal RISC-V ISA and Memory Configuration
+[NOTE]
+The default bootloader image was compiled for a minimal `rv32e_zicsr_zifencei` ISA configuration and only requires a
+RAM size of at least 256 bytes. Both constraints ensure that the bootloader can be executed by any actual CPU/processor
+configuration. However, the bootloader can recompiled with different capabilities. See the User Guide
+https://stnolting.github.io/neorv32/ug/#_customizing_the_internal_bootloader for more information.
 
 The NEORV32 bootloader (`sw/bootloader/bootloader.c`) provides an optional built-in firmware that
 allows to upload new application executables at _any time_ without the need to re-synthesize the FPGA's bitstream.

docs/userguide/customizing_the_bootloader.adoc

@@ -12,7 +12,7 @@ bootloader ROM) and the processor has to be re-synthesized.
 
 [NOTE]
 Keep in mind that the maximum size for the bootloader is limited to 8kB and it should be compiled using the
-minimal base & privileged ISA `rv32i_zicsr_zifencei` only to ensure it can work independently of the actual CPU configuration.
+minimal base & privileged ISA `rv32e_zicsr_zifencei` only to ensure it can work with any actual CPU configuration.
 
 .Bootloader configuration parameters
 [cols="<2,^1,^2,<6"]