Update EIP-7928: cap max items in BAL

Merged by EIP-Bot.

Author: nerolation

EIPS/eip-7928.md

@@ -111,6 +111,23 @@ Addresses with no state changes **MUST** still be present with empty change list
 
 Entries from an [EIP-2930](./eip-2930.md) access list **MUST NOT** be included automatically. Only addresses and storage slots that are actually touched or changed during execution are recorded.
 
+### Block Access List Size Constraint
+
+The block access list is constrained by available gas rather than a fixed maximum number of items. The constraint is defined as:
+
+```
+bal_items * ITEM_COST <= available_gas + system_allowance
+```
+
+Where:
+
+- `bal_items = storage_reads + addresses`
+- `ITEM_COST = GAS_WARM_ACCESS + TX_ACCESS_LIST_STORAGE_KEY_COST`
+- `available_gas = block_gas_limit - tx_count * TX_BASE_COST`
+- `system_allowance = (15 + 3 * (MAX_WITHDRAWAL_REQUESTS_PER_BLOCK + MAX_CONSOLIDATION_REQUESTS_PER_BLOCK)) * ITEM_COST`
+
+The `storage_reads` is the total number of storage accesses across all accounts, and `addresses` is the total number of unique addresses accessed in the block. The `system_allowance` term accounts for system contract accesses that occur outside of user transactions. `MAX_WITHDRAWAL_REQUESTS_PER_BLOCK` is defined in [EIP-7002](./eip-7002.md) and `MAX_CONSOLIDATION_REQUESTS_PER_BLOCK` is defined in [EIP-7251](./eip-7251.md).
+
 ### Gas Validation Before State Access
 
 State-accessing opcodes perform gas validation in two phases: